Voltage spikes generally occur when switching on and off motorized components like window motors,wiper motors and even the starter. They are created when the magnetic field collapses in the motor when turning it off. These voltage spikes can cause damage to sensitive computer components, found in later vehicles, causing the vehicle to run poorly and/or inefficiently.
A weak or bad battery and loose or corroded connections can aid in the destructive forces of voltage spikes. A good battery acts as a large capacitor to absorb these spikes, so it is important to maintain the battery in good condition and keep the connections clean and tight to help prevent this kind of damage.
Proper and clean grounding of components is very important also. When a voltage spike is forced across a path of least resistance it can literally fry other lessor components and maybe start a fire in the vehicle. Though rare, it sometimes has happened. Have you ever seen a car on the freeway on fire?
Alternators have some built in spike absorbing parts. Many of the older units had capacitors (also referred to as condensers) either inside or mounted on the back of the units. In later vehicles, they used avalanche diodes to do the trick by allowing excess voltage to leak past the diode in reverse, sort of like a pressure relief valve.
Bottom line and I'll repeat, always maintain a good battery in the vehicle and make sure to keep the connections clean. Don't keep charging a weak battery to get by, until it quits all together. By then the damage may have already occured. Proper maintanence can give you more years of trouble free service!
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Tuesday, December 28, 2010
Monday, December 13, 2010
About Alternator Functioning
It's been a couple of weeks since I've posted anything. It's been dead in the shop and nothing had sparked any ideas for a post until last week. A Delco CS130 series alternator from the mid 1990's GM products came in with erratic charging problems and was overcharging. It had a bad regulator, which is the part that controls the output of the alternator. It was also a low quality rebuild from a parts store and probably wouldn't have failed if the rebuilding company had used a better quality regulator.
Anyway this sparked an idea for posting something about alternator functions, to help you diagnose your trouble. Generally if an alternator is not charging on the vehicle, it could be any of the components. Each manufacturer and model of alternator has it's own quirks and reasons they generally fail, so without knowing what your alternator is, it would take hours and hours of writing, that could fill a large book to cover all of what's out there. There are however a few tell tail signs to look for when diagnosing your trouble that might help determine what's wrong.
If the alternator overcharges and is cooking the battery, or charges for a minute when you first start the vehicle when it's cold then quits, then it's most likely it's the regulator. If the regulator internally has a loose ground it can also cause it to overcharge. A totally non charging alternator can be the regulator but it's usually some other component. Another component that can cause overcharging, but is very rare and usually will cause other alternator damage is a shorted rotor. I've only come across a shorted rotor about four or five times in the 11 years I have been working on them.
If the alternator only charges intermittently, whether hot or cold and progressively gets worse, then it's probably the brushes worn out. It can also be a loose connection either inside or outside the alternator. Check to make sure all the wire connections are tight! This is more common on Ford alternators and on Denso (Nippondenso) alternators that are used on Toyota and Chrysler products but can happen on other models.
Alternators that make a howling noise and may charge at a reduced rate, or not at all, usually has a bad rectifier. A bad stator or a combination of both can also cause this condition. This is more common on Delco alternators of the 80's and 90's GM vehicles. (GM, isn't that now Government Motors?)
If the alternator is making a loud popping noise or roars like a waterfall, it will usually have bad bearings. It could either be charging or not. A squealing noise is generally not a bearing noise and is more than likely the belt slipping, due to either being worn, adjusted too loose or a weak tensioner. The only exception to this is when the bearing shells or galls out, but it will usually lock up at that moment. If the bearing comes apart and looses it's balls or rollers it will usually cause more expensive damage to the alternator and may be cheaper to just replace the entire unit, rather than fixing it. Of course only a qualified rebuilder can only tell you if it's that bad!
Anyway this sparked an idea for posting something about alternator functions, to help you diagnose your trouble. Generally if an alternator is not charging on the vehicle, it could be any of the components. Each manufacturer and model of alternator has it's own quirks and reasons they generally fail, so without knowing what your alternator is, it would take hours and hours of writing, that could fill a large book to cover all of what's out there. There are however a few tell tail signs to look for when diagnosing your trouble that might help determine what's wrong.
If the alternator overcharges and is cooking the battery, or charges for a minute when you first start the vehicle when it's cold then quits, then it's most likely it's the regulator. If the regulator internally has a loose ground it can also cause it to overcharge. A totally non charging alternator can be the regulator but it's usually some other component. Another component that can cause overcharging, but is very rare and usually will cause other alternator damage is a shorted rotor. I've only come across a shorted rotor about four or five times in the 11 years I have been working on them.
If the alternator only charges intermittently, whether hot or cold and progressively gets worse, then it's probably the brushes worn out. It can also be a loose connection either inside or outside the alternator. Check to make sure all the wire connections are tight! This is more common on Ford alternators and on Denso (Nippondenso) alternators that are used on Toyota and Chrysler products but can happen on other models.
Alternators that make a howling noise and may charge at a reduced rate, or not at all, usually has a bad rectifier. A bad stator or a combination of both can also cause this condition. This is more common on Delco alternators of the 80's and 90's GM vehicles. (GM, isn't that now Government Motors?)
If the alternator is making a loud popping noise or roars like a waterfall, it will usually have bad bearings. It could either be charging or not. A squealing noise is generally not a bearing noise and is more than likely the belt slipping, due to either being worn, adjusted too loose or a weak tensioner. The only exception to this is when the bearing shells or galls out, but it will usually lock up at that moment. If the bearing comes apart and looses it's balls or rollers it will usually cause more expensive damage to the alternator and may be cheaper to just replace the entire unit, rather than fixing it. Of course only a qualified rebuilder can only tell you if it's that bad!
Friday, November 26, 2010
You Get What You Pay For!
Recently, I've had a couple of customers tell me that they can buy older style (1970's era) Delco starters at the local parts stores for $39.00. One of them had already purchased a marine sealed one for that price with a one year warranty. How is this possible? How can parts stores purchase these, in today's prices, for a low enough price to sell them for that amount and still make a decent mark up?
I'll tell you! They have to cut quality and are rebuilt in third world countries, where they pay probably less then a dollar an hour for the work. The problem with this is that both quality and workmanship suffer. Quality suffers by way of using inferior parts, used parts that should not be reused without rewinding or repair and new parts of very low quality with inferior metals and plastics that work fine when new, but after being in the extreme temperature changes and vibrations under the hood, will eventually fail, sooner rather than later. Many won't make the one year warranty. Workmanship also suffers in that many of the workers are unskilled and don't really know how to watch for problems, when assembling or stripping or leaving bolts and screws loose, which will also cause problems. How many of these units have you taken on and off, for warranty after warranty, until you finally get a good one?
How do I know this? I've worked on many of these units and seen first hand the poor quality! I stood there and told my customer I couldn't believe how much they are charging for these units because I know how much I have to put into one, to repair it.
Speaking about this particular starter, on average if the unit comes in dirty and needs a standard rebuild, using quality wear parts like brushes, bushings, drive and solenoid, the parts alone cost about $25.00 and labor would usually average around $42.00. That's a total of $67.00! Now If I have to replace the armature and/or field coils, that substantially increases the repair cost. To order a 'quality' rebuilt or new starter including shipping, cost me around a hundred bucks! Add my markup of around $40.00 and you see that I can't even begin to compete cost wise with the parts stores. I can however compete on quality, so if you only care about cost, then you get what you pay for! If you want a unit to last and be trouble free, you should take it to a qualified and trusted rebuilder and pay the additional cost to repair yours or get a quality unit!
I'll tell you! They have to cut quality and are rebuilt in third world countries, where they pay probably less then a dollar an hour for the work. The problem with this is that both quality and workmanship suffer. Quality suffers by way of using inferior parts, used parts that should not be reused without rewinding or repair and new parts of very low quality with inferior metals and plastics that work fine when new, but after being in the extreme temperature changes and vibrations under the hood, will eventually fail, sooner rather than later. Many won't make the one year warranty. Workmanship also suffers in that many of the workers are unskilled and don't really know how to watch for problems, when assembling or stripping or leaving bolts and screws loose, which will also cause problems. How many of these units have you taken on and off, for warranty after warranty, until you finally get a good one?
How do I know this? I've worked on many of these units and seen first hand the poor quality! I stood there and told my customer I couldn't believe how much they are charging for these units because I know how much I have to put into one, to repair it.
Speaking about this particular starter, on average if the unit comes in dirty and needs a standard rebuild, using quality wear parts like brushes, bushings, drive and solenoid, the parts alone cost about $25.00 and labor would usually average around $42.00. That's a total of $67.00! Now If I have to replace the armature and/or field coils, that substantially increases the repair cost. To order a 'quality' rebuilt or new starter including shipping, cost me around a hundred bucks! Add my markup of around $40.00 and you see that I can't even begin to compete cost wise with the parts stores. I can however compete on quality, so if you only care about cost, then you get what you pay for! If you want a unit to last and be trouble free, you should take it to a qualified and trusted rebuilder and pay the additional cost to repair yours or get a quality unit!
Tuesday, November 16, 2010
Poor Quality, Part 4 Ferguson Tractor Starter
This Delco starter, which looked like a rebuild from someone, came in because the customer complained that it was dragging really bad. I tested it on the bench and it for sure was dragging. It sounded like the bushings were worn out.
After taking it apart I found that the bushings were alright and it failed because the brushes were worn out all the way down to the metal brush holders and one had worn half way through the brush screw. The reason this starter failed is wrong brushes. They ended up using a smaller brush out of a later unit that didn't belong in this one. Either someone couldn't find the right brushes or purposely picked up the wrong ones. Either way, the starter prematurely failed.
Because this particular starter is a smaller diameter unit and has tight clearances, the longer standard brushes are too long and it takes a short but wide brush with offset screw holes to properly work. I Installed the correct brushes and trued up the armatures commutator, which was chewed up by the brush holders rubbing against it, and finally got it going again.
So this shows that if the right parts are used and someone watches their own workmanship to make sure everything is correct, you'll have a unit that lasts, instead of fails!
After taking it apart I found that the bushings were alright and it failed because the brushes were worn out all the way down to the metal brush holders and one had worn half way through the brush screw. The reason this starter failed is wrong brushes. They ended up using a smaller brush out of a later unit that didn't belong in this one. Either someone couldn't find the right brushes or purposely picked up the wrong ones. Either way, the starter prematurely failed.
Because this particular starter is a smaller diameter unit and has tight clearances, the longer standard brushes are too long and it takes a short but wide brush with offset screw holes to properly work. I Installed the correct brushes and trued up the armatures commutator, which was chewed up by the brush holders rubbing against it, and finally got it going again.
So this shows that if the right parts are used and someone watches their own workmanship to make sure everything is correct, you'll have a unit that lasts, instead of fails!
Thursday, November 11, 2010
Testing Generators on Vehicle or Tractor, Part 2
To fully understand this post, I suggest reading Part 1 first!
'B' circuit generators, like what is on Ford products, differ from 'A' circuit generators by the way they are controlled. To test a 'B' circuit generator on the vehicle, remove the field 'F' wire from the generator and set it aside so it won't touch anything, then using a short jumper wire, jump across to the 'ARM' or 'GEN' terminal on the generator or better yet, use a longer wire and jump to the hot side of the battery, which could either be positive or negative depending on which side is grounded. This will kick the generator into full charge which can either be read by the gauge in the dash or using a meter across the battery. Be careful, because I've found that these generators are usually have a higher amp output than the 'A' circuit generators and will really cook!
To polarize a 'B' circuit system, After everything is hooked up and before starting the engine, Remove the field wire from the REGULATOR'S 'F' terminal and touch that wire to the 'BAT' terminal on the regulator. Just hold it on, for only a second and when you remove it there should be a spark. Warning, do not touch the regulators 'F' field terminal to the 'BAT' battery terminal or you will fry the regulator! (As always follow the instructions you receive with the new regulator if they differ with what is written here!)
'B' circuit generators, like what is on Ford products, differ from 'A' circuit generators by the way they are controlled. To test a 'B' circuit generator on the vehicle, remove the field 'F' wire from the generator and set it aside so it won't touch anything, then using a short jumper wire, jump across to the 'ARM' or 'GEN' terminal on the generator or better yet, use a longer wire and jump to the hot side of the battery, which could either be positive or negative depending on which side is grounded. This will kick the generator into full charge which can either be read by the gauge in the dash or using a meter across the battery. Be careful, because I've found that these generators are usually have a higher amp output than the 'A' circuit generators and will really cook!
To polarize a 'B' circuit system, After everything is hooked up and before starting the engine, Remove the field wire from the REGULATOR'S 'F' terminal and touch that wire to the 'BAT' terminal on the regulator. Just hold it on, for only a second and when you remove it there should be a spark. Warning, do not touch the regulators 'F' field terminal to the 'BAT' battery terminal or you will fry the regulator! (As always follow the instructions you receive with the new regulator if they differ with what is written here!)
Thursday, October 28, 2010
Testing Generators on the Vehicle or Tractor, Part 1
Testing 'A' circuit generators are pretty easy. First, disconnect the 'F' terminal either at the generator or the regulator. You must do this to prevent damaging the regulator if it is still good. Start the engine and have someone watch the ammeter (which is the gauge that should be being used with a generator) and then use a jumper wire and ground the 'F' terminal on the generator. If the generator is good, it will go into full charge instantly and show that way on the meter. What ever you do, don't touch the 'F' terminal on the regulator when you do this.
If the generator does go into full charge then it is probably good. So after you reconnect the 'F' wire, if it doesn't charge then the problem is probably the regulator and will need replaced. You could also remove the regulator's cap and try to clean the contacts to see if it will work. Also make sure the regulator has a good ground as that will also cause it to not work.
One last thing you can try, is to re-polarize the regulator. This has never worked for me, as my problems have always been elsewhere, but it's worth a try. To polarize the regulator on an 'A' circuit system, With the engine off and everything connected including the battery, (positive or negative ground) take a jumper wire and momentarily touch the regulators 'BAT' terminal to the 'ARM' (or 'GEN' terminal, which ever way it is marked). Only hold the wire on it for a second and them remove it. It will spark when removing it and that is normal. If there is no spark, check the wiring to make sure you have battery juice to the 'BAT' terminal by checking it with a test light or meter. Once again, DO NOT touch the 'F' terminal or it will instantly fry the regulator. (My directions for polarization are only general and you should follow the directions you receive with the new regulator if they differ from what I have stated here!)
On some regulators the 'ARM' terminal is in back or underneath and may be hard to access. In that case you can jump from the 'BAT' to the 'A' terminal on the generator as the wire from the 'ARM' terminal goes directly to the 'A' terminal.
One final thought today, most regulators used with 'A' circuit Delco generators have either three or four terminals. The three terminal units terminals will be marked 'BAT', 'ARM' (or 'GEN') and 'F'. Four terminal units are marked 'L', 'BAT', 'F' and the terminal in back or on bottom 'ARM'. The 'L' terminal on the four terminal unit, if used, is for the vehicle's or tractor's lights and is usually wired directly to the light switch.
I will cover 'B' circuit generators in the next post.
If the generator does go into full charge then it is probably good. So after you reconnect the 'F' wire, if it doesn't charge then the problem is probably the regulator and will need replaced. You could also remove the regulator's cap and try to clean the contacts to see if it will work. Also make sure the regulator has a good ground as that will also cause it to not work.
One last thing you can try, is to re-polarize the regulator. This has never worked for me, as my problems have always been elsewhere, but it's worth a try. To polarize the regulator on an 'A' circuit system, With the engine off and everything connected including the battery, (positive or negative ground) take a jumper wire and momentarily touch the regulators 'BAT' terminal to the 'ARM' (or 'GEN' terminal, which ever way it is marked). Only hold the wire on it for a second and them remove it. It will spark when removing it and that is normal. If there is no spark, check the wiring to make sure you have battery juice to the 'BAT' terminal by checking it with a test light or meter. Once again, DO NOT touch the 'F' terminal or it will instantly fry the regulator. (My directions for polarization are only general and you should follow the directions you receive with the new regulator if they differ from what I have stated here!)
On some regulators the 'ARM' terminal is in back or underneath and may be hard to access. In that case you can jump from the 'BAT' to the 'A' terminal on the generator as the wire from the 'ARM' terminal goes directly to the 'A' terminal.
One final thought today, most regulators used with 'A' circuit Delco generators have either three or four terminals. The three terminal units terminals will be marked 'BAT', 'ARM' (or 'GEN') and 'F'. Four terminal units are marked 'L', 'BAT', 'F' and the terminal in back or on bottom 'ARM'. The 'L' terminal on the four terminal unit, if used, is for the vehicle's or tractor's lights and is usually wired directly to the light switch.
I will cover 'B' circuit generators in the next post.
Monday, October 18, 2010
Generators, 'A' or 'B' Circuit?
I thought I'd throw in a little information about auto and tractor generators this week. Please consider this information as general in nature. You should find an experienced electrical technician for proper identification and testing.
The main difference in the various generators that were produced in older vehicles and tractors is that there were either 'A' circuit or 'B' circuit units. What this means is how the units output, is controlled by the regulator, regulating the field current (to the 'F' terminal on the generator). In the 'A' circuit generators, which were mainly Delco units, were controlled by the regulator varying the ground to the field. In 'B' circuit generators, the regulator applied current to the field, which was internally grounded.
Most 'A' circuit units were on GM products and many farm and industrial tractors. 'B' circuit units were mainly found on Ford products and possibly industrial units, but there were a few 'A' circuit Ford tractor units produced. Later generators on Ford tractors were all Lucas brand 'B' circuit generators. Other manufacturers like Autolite and Prestolite made generators also, and they could be either 'A' or 'B' circuit. Delco may have made a 'B' circuit generator, but I've never came across one!
I will offer a little testing and advice for generators in the next post!
The main difference in the various generators that were produced in older vehicles and tractors is that there were either 'A' circuit or 'B' circuit units. What this means is how the units output, is controlled by the regulator, regulating the field current (to the 'F' terminal on the generator). In the 'A' circuit generators, which were mainly Delco units, were controlled by the regulator varying the ground to the field. In 'B' circuit generators, the regulator applied current to the field, which was internally grounded.
Most 'A' circuit units were on GM products and many farm and industrial tractors. 'B' circuit units were mainly found on Ford products and possibly industrial units, but there were a few 'A' circuit Ford tractor units produced. Later generators on Ford tractors were all Lucas brand 'B' circuit generators. Other manufacturers like Autolite and Prestolite made generators also, and they could be either 'A' or 'B' circuit. Delco may have made a 'B' circuit generator, but I've never came across one!
I will offer a little testing and advice for generators in the next post!
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