1969 Westfalia Generator Light On

[Amskeptic]

Still seems like it's charging at speed, but nada at idle. What I don't have is a feeling to what should be seen on a system with no issues.

It seems like all components are doing their job. Do you have the ground wire on the generator that screws under a self-tapping screw along the top? Did your relay style regulator have a good ground?

You are just tempting me to part the waters and get over there in-between Michigan and Illinois.
Colin

[jeb1978]

Ground wire for the generator is attached to a small screw that's threaded into the generator body itself... ground goes to the upper regulator mounting screw.

The regulator itself does not have a separate ground wire; it grounds through it's mounting bracket (this is the way this Bus has been since I've owned it).

So, in effect, both the generator and regulator are grounded at the same point. I've checked continuity to ground (battery negative post) from the generator and regulator and get low resistance (0.2 ohms). Guess I'll check it again.

[vdubyah73]

I think you already know this but generators don't charge at low RPM. Install a voltmeter gauge and as long as you show good voltage while driving don't worry.

[jeb1978]

I understand (somewhat) the limitations of a generator, but why the light now at idle when it wasn't there before? Shouldn't the voltage regulator be balancing the voltage in such a way to keep the light off?

[Hippie]

I understand (somewhat) the limitations of a generator, but why the light now at idle when it wasn't there before? Shouldn't the voltage regulator be balancing the voltage in such a way to keep the light off?

Ya. There should be enough voltage there to shut off the light.

[jeb1978]

I removed the 2nd generator with the intention of having it replaced under warranty, again. I took it to the FLAPS, and he suggested I take it to a local auto electric shop to have it tested.

The electric shop tested it, and proclaimed it good. They suggested that I replace the regulator, or bring it in to have it tested by them as a system.

So now I'm at a crossroads whether to replace the generator again or not, and if not, what else to look at?

[hambone]

If it tested good, replace the regulator.

[jeb1978]

I've replaced the regulator twice already.

[hambone]

If you have a known good generator and a known good regulator then the only thing left is wiring.

[Amskeptic]

The electric shop tested it, and proclaimed it good. They suggested that I replace the regulator, or bring it in to have it tested by them as a system.

So now I'm at a crossroads whether to replace the generator again or not, and if not, what else to look at?

Bring it in and have it tested as a system. Then you will know for certain that it is in the wiring. The older VW manuals had excellent and comprehensive write-ups on how to test the system. I think you need a potentiometer however to replicate the load test.
Colin

[jeb1978]

Well, the auto electric's shop version of testing as a "system" was to put their analyzer on the battery and that was it. I might try and go back when the guy who tested my generator is there, since he seemed to know more about what was going on.

Interestingly enough, they said it's charging just fine at idle, and at RPM. Opposite of what the other shop told me.

I ended up replacing both the battery cables since the clamps were getting pretty messed up from all the removing and installed I've been doing lately. No change to the GEN light, but at least the clamps aren't all rounded off.

I also took the harness from the generator to the regulator off and "load" tested by using two wires at a time to power a headlight (which worked fine, all wires good).

I built my own generator-to-regulator harness and installed it, no change to the GEN light. I bypassed the wire from terminal 61 to the dash, no change to the GEN light.

I have two of the solid state Bosch regulators, both operate the same when installed, GEN light on at idle, off at RPM.

I'm still suspicious of this new generator, but I wish I would have had my old one tested last year before I turned it in. I wonder if it would have tested good? Not that I wouldn't have had the same issue.

[vdubyah73]

I'm thinking a feedback on the instrument cluster wiring. Don't know if the '69 wiring is similar to the '77, power to the warning light is also the field exciter. With the engine off, power flows from the fuse box through the warning lite to the generator causing the warning light to light. The generator is the ground. Once the generator starts generating, power is available from both ends, canceling out the ground. The same wire from the fuse box also powers dash lights, fuel gauge, turn signal indicators and who knows what else. If the wire from the fuse box has high resistance from corrosion or just from too many years of vibration, the above mentioned things will draw power from the other end of the circuit, the generator. This power will come through the generator warning lamp, causing it to light. Does the warning lamp get brighter with the lights on? Does it pulse with the turn signals?

[jeb1978]

The GEN light is on at the same intensity regardless of the turn signals, etc. I measured voltage drop from the fuse box to the GEN light base at key on engine off, and it was less than a volt (which I guess it should be less than this considering the length of the wires).

But the GEN light persists. I drove the Bus to Indy and back today (about 120 miles). The light was only on at idle on the way up, but on the way back, I would have to rev the engine to well over 3000 RPM to turn the light out. It would stay out until I went back to idle, and then I would have to repeat the process to turn it out. The speed it took to turn the GEN light out became higher as the day went on, to the point it took over 4000 RPM once I arrived back home.

I checked the battery voltage when the GEN light was on... below 12 volts. If the light was on when I rev'd the engine up, battery voltage didn't increase. If the light was off, battery voltage increased.

I still think this generator is the root of all evil, regardless of what the shop said when it was tested. I also noticed the commutator on it has no grooves... it's solid (Bentley says the grooves should have a minimum depth of something I can't recall right now; my old scrap generators have this). I'll probably take it back. Again.

I'm at the point of thinking it's alternator time. I've put way too much time into this the past few weeks with no success... not to say an alternator is going to be perfect, but it might at least be a new set of problems.

[Amskeptic]

The GEN light is on at the same intensity regardless of the turn signals, etc. I measured voltage drop from the fuse box to the GEN light base at key on engine off, and it was less than a volt (which I guess it should be less than this considering the length of the wires).

But the GEN light persists. I drove the Bus to Indy and back today (about 120 miles). The light was only on at idle on the way up, but on the way back, I would have to rev the engine to well over 3000 RPM to turn the light out. It would stay out until I went back to idle, and then I would have to repeat the process to turn it out. The speed it took to turn the GEN light out became higher as the day went on, to the point it took over 4000 RPM once I arrived back home.

I checked the battery voltage when the GEN light was on... below 12 volts. If the light was on when I rev'd the engine up, battery voltage didn't increase. If the light was off, battery voltage increased.

I still think this generator is the root of all evil, regardless of what the shop said when it was tested. I also noticed the commutator on it has no grooves... it's solid (Bentley says the grooves should have a minimum depth of something I can't recall right now; my old scrap generators have this). I'll probably take it back. Again.

I'm at the point of thinking it's alternator time. I've put way too much time into this the past few weeks with no success... not to say an alternator is going to be perfect, but it might at least be a new set of problems.

The above describes perfectly the failure of my first alternator. The bearings were getting worn, and the rotor was shorting out until I revved it sufficiently to "spool the shaft" backwards. I do not know if a generator could fail the same way with the armature being on the rotating assembly, but I agree that you must seek redress with this generator.
Colin

[jeb1978]

Well, it's fixed.

I gave up on the generator, and generators in general. My local FLAPS gave me credit towards an alternator (cost of alternator minus what the rebuilt generator cost), so I opted for a new Bosch AL82. I found a good German alternator stand, swapped over the parts, changed some wiring, and done.

Light is on at engine start until the first throttle blip (which is normal by all accounts I have read). Battery voltage is ~13 volts at idle. No more GEN light.

I don't exactly know what went wrong or what was bad with what I had, but I'm leaning towards the rebuilt generator(s)... and I'm not really in the mood to find out. It works, time to drive.