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.

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!

Fewer Breakdowns

I've been traveling the last week and a half and noticed that there are fewer cars broke down on the road than we used to see, say 30 years ago.  Technology has made them last longer and made than more reliable than earlier vehicles.  Just considering the shear number of vehicles out there, you'd think there should be hundreds of broke down vehicle on the road.  With the advances in tire design, you seldom even see flat tires out there either.  Unfortunately, the trade off being that you can no longer work on your own cars with just basic mechanical skills any more!  Is this a good thing or a bad thing?

Once these cars quit running they must be towed to a mechanic to get them running again.  I remember many times on my old 60's to 70's cars and pickups, being able to repair them on the road or able to limp them home where I could fix them.  Those were the days!

Doctors VS. Mechanics, Who Should Be Paid More?

If you think about this for a minute and compair the two jobs, you may see that the mechanic may actually have a tougher and harder job than most doctors.

First off, the human body is only made in two models, male and female!  Though there are different sizes and ages that play a factor in their treatment, basicly the internal organs are all the same and don't change when a new baby comes along.  Granted there are always new technics and drugs for treatment that come about and new diseases that pop up, not all doctors will learn all of these as only specialists will come along to learn and use some them.

Now look at all the automobiles coming off the rack each and every year.  Consider all the manufacturers and all the models of vehicles they produce.  Then throw in all the different engine sizes and transmission options and even body options and everything is different and nothing is interchangable, none of them have the same readings when testing and diagnosing.  Every year they produce new models with something more complex and difficult to diagnose and work on!  So when you bring your car into the mechanic, he now has to go online and learn how to diagnose and fix your car.  Basic mechanic skills that were learned years ago that would allow a mechanic to fix almost any car, do not come into play now.  Granted they help and without them they would not even know where to start, they really only aid in physically identifing and changing the defective parts.

Every time a patient goes to see the doctor, the doctor relies on his knowledge and experience to treat the patient.  When a person brings in their devective vehicle, the mechanic is faced with a literal nightmare of wires and components that he has to stop and learn how to fix on the spot!

Who do you think should be paid more?

Too Many Different Parts!

It's been dead in the shop, so not much has been happening or has been worth mentioning, except an issue a customer had with a starter off a 2002 Mercedes CLK.  He ordered a starter off the Internet and then brought the vehicle to the mechanics shop, that's across the street from my shop, to swap out the starter.  They had trouble installing the new starter because it was about an inch longer than the old one and would not go into place! 

So the customer brought the old starter to my shop to see if I could fix it right then!  Because of the thousands and thousands of different parts that don't interchange I didn't have or wouldn't even stock the part I needed to repair his starter.  Then they brought me the new starter to see if I could change the parts needed over to the old starter, but as it turned out the new starter was also larger in diameter than the old starter and the parts wouldn't interchange.  With the customer's permission, the mechanic ground out some metal in the frame or something, so he could get the longer starter into position.

Checking the computer I found that Mercedes used two different models of starter for that vehicle and engine size.  Why?  Why in the hell did they do that?  Who's the SOB who thought up using more than one starter?  Why didn't they just produce one starter for the vehicle or for a large number of their vehicles!  This practice, used by all the manufacturers, has caused a large number of headaches for a lot of people and wasted my time, my customer's time and the mechanics time dealing with this issue.  Maybe if the auto manufacturers had to pay us for all the lost time dealing with issues like this, they would change the way they built cars and made them simpler and more interchangeable!

Disassembling your unit and then bringing it to me to fix!

There are several reasons people take their starter or alternator apart.  One is they are usually don't have any money to buy a replacement, can't find one at a salvage and hope they can figure out what's wrong and repair it themselves to save some money.  Another is that they want to find out how bad it is and whether it's worth repairing.  Some people think that if they disassemble it, it will save them some of the labor expense of having me tear it down.  I should also add that some people don't trust the person they will have work on it and don't want to get ripped off by being over-charged for parts they don't need.  Unfortunately, there are some unscrupulous repair men out there that do rip some people off!

A lot of times customers quickly find out that these newer units are not like the old Delco units that were simple to work on and are too complicated to fix!  Whatever the reason, they end up bringing me the mess they have created and want me to fix it.  This presents me with several problems.  The first is, since they took it apart, I may not know how to put it back together again.  This was a real problem the first three or so years I was doing this business.  Though this sounds like no big deal, you have no idea the hundreds or even thousands of variations of starters and alternators there are out there!

With my experience now, I can usually figure out how they go together, but there are parts that can be indexed in several different positions, housings that align in different positions and internal parts that can be switched making the unit operate incorrectly.  Since I didn't take it apart and mark the positions, I have to guess how it goes back together when I reassemble it and I may have to re-take it apart several times to reposition something to get it to work properly!

Another problem is that they leave some of the parts at home, or worse they loose them!  There are some units out there that have small loose parts that the customer doesn't even know are there, that will fall out and they don't even notice them.

Many of the units have complicated construction and if they don't know the 'tricks of the trade' so to speak, the customers will also sometimes damage or break 'beyond repair' some of the components, trying to disassemble or work on the units themselves!

The last thing is that now I can't test the unit, which could help me figure out what's wrong with it.  Testing it before hand can help me find defective parts the won't show up otherwise, until I have fixed the other problems, reassembled and tested the unit.  This would end up requiring me to disassemble the unit again and replace more parts, sometimes doubling the labor expense!

Instead of saving the customer some of the labor costs, it usually ends up costing them more to repair the unit, than if they had just brought it to me still all together!  So, y'all go right ahead and disassemble you units so I can make a lot more money!  Cha-ching!

Working on 2000 and Later Vehicles

The following is my opinion and just my opinion.  Take it for what it's worth!

I believe that if you are not an ASE certified mechanic and have the proper testing equipment, then you have no business going under the hood of a 2000 or later vehicle!  No old school procedures will work when trying to diagnose problems or doing any repairs and will probably cause more expensive repairs by damaging sensitive computer components!

I know all you do-it-yourself people out there think you should be able to fix anything and have had few problems working on vehicles up to now, but these later vehicles just don’t work that way.  I personally have quit working on 2000 and later alternators.  I’ve had too many failures that have cost me more money than I ever made off the unit and I don’t believe the fault was mine or the unit I sold them, but I had to warrant them anyway.  I can’t count on the installer to take the proper care when hooking up the wires, that he doesn’t create a spark and damage the sensitive regulator circuitry! 

What makes matters worse is that if the battery goes dead, you have to have the car towed to a dealer or a qualified mechanic to reprogram the cars computer.  You can't jump start it and you can't just change the battery.  Makes you wonder how much it will cost you every time the battery runs down because you left on a light or the battery fails.  It's been my experience that I only get about three and a half years out of a battery and I don't want to buy one prematurely just to keep me from paying the dealer an extra hundred bucks to reprogram the computer in my car.  To top this off you have to have a mechanic or a dealer to change the damn battery because they have to hook up a power source to the vehicles computer while removing and installing the battery to keep the computer active!  WHAT A LOAD OF CRAP!

The problems with these are both political and the technology race.  The damn politicians keep passing laws for vehicle safety and emissions. Though some of these laws have made things cleaner and safer, there seems to be overkill to some of this, which has forced auto manufacturers to come up with technology that will keep up with the mandates.  This technology costs lots of money and causes extra problems when the car malfunctions.  Also, it is a ploy to make you have to bring your car to the dealer and it also makes the repairs so expensive!  Who pays for all of this?  WE do!  We do, in higher prices for new cars.  We do, for way overpriced diagnostic and repair costs.  We do, in simple repairs we should have been able to do ourselves but now have to pay the dealer!

This makes me wonder what's going to happen to the poorer people in this country.  There are millions of them, they cant afford the payments, taxes and insurance on a new car and the older cars are wearing out.  Even if they could afford a new car on extended payments, the warranty runs out and only one breakdown would render their car useless, as they could never be able to afford the cost of the repairs.

The politicians of both parties are so out of touch with the common people of this country that they only serve to hinder the problem instead of finding solutions to the problems!  I see no end in site toward a solution to all of this short of stop buying new cars and demand that the manufacturers build simpler, easier to fix cars!

Oh how I miss the days when cars were simple to work on!