Iltis Alternator Problems

[Matthew Reid]

I Had a similar issue the alt would occasionally over charge. I also had a faulty head lamp light switch it worked but would drop out on over load when the headlights were turned on. The Alt Over load had no corelation at all to whether the head lights were on or off. When I changed the switch the Alt over charge issue vanished.


Matthew

[rob love]

90% of the over voltage problems that I experienced on the Iltis were due to poor connections. Loose terminals at the batteries would cause the alternator to over compensate and in the end would boil the batteries and fry the alternator. Make sure the cables are clean and tight at the batteries. Another potential problem area is the main connection at the starter. It acts as a junction for a number of wires. If this is loose, it also results in an over voltage problem. You can also check the connections at the master switch. Also, a bad battery (or two) can cause the over voltage problem. Check the batteries cell condition with a hydrometer; all cells should be equal within 20 points of each other. A single bad cell can cause the problems you are describing. Hydrometers are available at Cdn tire for under $10. If a cell is bad, the battery must be replaced, and on a 24 volt system, both batteries should be of relatively equal condition.

As an aside, there was a small bridge on the replacement alternators that also cause a bit of a problem. It was found that the vehicles could be started without the master switch if this bridge was allowed to remain. The bridge ran from the positive stud on the alternator over to the field (IIRC).

[Yeo.NT]

The alternator is not your problem, If i can produce voltage 32v it because the regulator is telling it to produce that much. Your regulator is the problem, try a different regulator and set it to charge at 27-28v

[rob love]

Originally Posted by Yeo.NT

The alternator is not your problem, If i can produce voltage 32v it because the regulator is telling it to produce that much. Your regulator is the problem, try a different regulator and set it to charge at 27-28v

Agreed that if it's charging, just the regulator portion can be changed, but if two different alternators are doing the same thing, and the adjustment won't work, then one should be looking for an external problem. Mind you, it would not be the first time someone installed a red herring (a bad alternator to replace a bad alternator).

[Rpoolie]

I just went through the same troubles (sporadic overcharging).
After checking all the grounds, finally removed the alternator and regulator and asked a local alt/gen repair shop to test.
Bottom line, after testing the reg was found to be faulty and was replaced, with no troubles since.
Cost was $140.00 taxes in.
The best advice to offer you is to send the unit to a repair shop for testing.
Would have saved me some time and frustration!

[antonio]

So here's the update: as I've said in my first post, i have 2 iltis that should run, so I'll call them iltis 1 and 2.

Iltis 1

Problem: Alternator 1 is overcharging to 32 volts and more within 15-30 seconds of engine start (not sporadic).

-I've tried cleaning the battery terminals, the connection at the starter, the ground next to the master key and every connection on the alternator. -No change Haven't touched the split connection of the positive cable or the connection at the master switch.

-I've also played musical chair with 4 batteries, 3 originals for the iltis and one random one. -No change I havent tested the batteries with a hydrometer yet.

-I took the alternator 2 from Iltis 2 and pluged it in Iltis 1, (although it was after it burned up... i'll explain below) This was interesting, the voltage stabilized at around 30.4-30.5 for a bit and then dropped down to 24... my guess is it is now completly fried but the voltage regulator may still work?

-I plugged in again the brand new (or its supposed to be) alternator, and it still overcharges to 32v

Iltis 2

Problem: A constant voltage of 24v accross the batteries and (as i later found out) smoking of the alternator

-I thought it was ok to use even if the alternator didnt charge the batteries, left of about a minute, came back and the alternator 2 was smoking like crazy

-I used the alternator 1 from Iltis 1 and there was still no change in the voltage. I suspect a bad connection/wire from the alternator to the rest of the system.

Rob you mentioned that a bad connection somewhere could cause the buildup of voltage, but since i can successfully and easily start the engine, wouldn't that mean that the connecitons are good? Also, unless there's another power generation equipment other than the alternator, how could the voltage increase? The alternator is behind the voltage regulator, so technically it shouldn't be able to raise the voltage beyond what the regulator dictates?

Also, when the alternator recharges the battery, is the voltage supposed to go up to as much as 30v? Or does it stay constant at 28?

My guess is that both Alternator 1 and the new alternator have defective regulators, and that theres a bad connection from the alternator to the electrical system on Iltis 2. I'll try changing the regulator from Alt 2 to Alt 1 and see what happens. Unless, is there a way to check if the regulator works or not? Maybe with the ohm meter?

I'm open to any suggestions and thought.
Thanks for your help!

[rob love]

Most of the failures I saw were not from an overload, but rather from an open. The alternator needs feedback from the system to regulate the voltage. This is called the field. If it is not getting it's feedback then it tries to put out more voltage to get the necessary feedback. It will continue to climb the voltage until it self destructs.

The regulator should charge at 26 to 28 volt. I always found that once they do their climb above 32, they are gone. You will have to change the regulator.

Rpoolie's advice about taking your alt for a test is a good one. They can change the regulator if needed, and test the unit on a bench tester. If all connections are OK, and the batteries test out OK with the hydrometer, then you should be good to go.