Red light on

[crvc]

I pulled the engine out to change the flywheel seal. The first thing I did was disconnect the battery. After replacing the flywheel seal and getting the engine back in the last thing I did was reconnect the battery. I got a momentary spark when the wrench touched a ground. But no fuses broke. It starts right up but the red light stays on. Did something happen when the wrench touched a ground? I used a 12volt tester. With the engine idling there's 12 volts at the coil but zero voltage at D+ on the 6 month old generator. Did the spark damage the generator?

TIA

kevin

[Marc]

I started with a stock '67 1500cc. I upgraded to 1650cc jugs, dual port heads... I'm still using the 1500cc tin but put in the alternator and fan from a 1973 engine...

So, is it currently a generator or an alternator?
It's not likely that a small momentary short would damage either. Alternators, with their aluminum housings, don't hold much residual magnetism when they're idle (generators usually have a "shelf-life" measured in months rather than days).
Alternators receive a voltage via the warning lamp filament when the ignition is on that creates sufficient current to "flash" the magnetic field so they'll start to charge. You say the lamp is on with the engine running, but is it on with the engine off and the key turned to "on"? If the charging and oil pressure warning lamps don't illuminate when the key is switched "on", there may be no voltage supplied to the bulbholder for the warning lamps. That wasn't fuse-protected until the early `70s, but who can say how your `67 has been wired...other posts you've made have raised some questions in that area.

Have you only started and idled the motor since fixing the front seal? Sometimes it takes a momentary blast to ~3000 RPM or so to "wake up" an alternator that's been sitting unused.


In future, when you disconnect the battery lift the cable from the negative terminal, not the positive. If they both need to come off (you're removing/replacing the battery) disconnect the negative first and reconnect it last. This way if your wrench contacts ground there will be no short.

[Ol'fogasaurus]

... It starts right up but the red light stays on...

Oil?

[Marc]

Starting with the `70 model year both warning lights were red. Prior to that the oil pressure light was green, but it was changed in deference to IDIOT American drivers who never read their owner's manual and think that green means "go".

One should always take a second to see that both warning lamps illuminate when the key is first switched "on", before cranking. They are the only stock "instrumentation" available and it's foolhardy to leave the driveway without knowing that they are capable of alerting you to a problem.

[Ol'fogasaurus]

Oh! My buggies never used the idiot lights (edit -in the speedo) so I guess I assumed that they were like American cars w/red meaning stop/there is a problem... I drove a VW in '60 or '61 for about 15 minutes then not again until my buggy in ~'91 - '93.

Lee

[crvc]

There's a red idiot light and a green idiot light. Both come on when I turn the key. And after starting the engine the green goes out but the red stays on. My mistake; It's a generator, not an alternator. I ran out of light last night so I drove it in the garage and quit for the night. It was dark enough I couldn't tell whether I've stopped the oil leak.

kevin

[Marc]

Do you have the original-style electromechanical voltage regulator:


...or a solid-state replacement type?


Certain that the wires all got hooked back up properly when the engine was reinstalled?

If the brushes are worn they can have insufficient spring tension to provide firm contact to the commutator bars, and a few days out of service (particularly if it's damp out) can allow oxidation to form that inhibits contact. Usually simply pressing on the brushes with the engine running is enough to "burn off" the corrosion and get the generator charging again, at least for a while. In the unlikely event that the voltage regulator got zapped by your spark-show, the generator should still work; that can be confirmed by disconnecting the wires from it and momentarily jumpering DF to ground with a voltmeter connected from D+ to ground; at a high idle the voltage should spike up above ~25V.

http://www.vw-resource.com/generator.html

[crvc]

I've got the original style regulator, similar to the upper photo. I've had little practice with a voltage meter but I think it showed 10 volts on the battery. And when revving the engine it showed no motion in the meter. Then I disconnected Df and D+ and connected the meter between D+ and the frame. With the engine revving the meter did move. Then I removed the fan belt. I put a jumper from Df to ground. Then ran a jumper from the battery positive to D+. Instead of the generator spinning I got a spark.

I remembered that I put in a starter relay a couple years ago. It's mounted to the frame on the left side next to the starter. I remember moving wires-without disconnecting any--while putting the insulated heat conduit back in. If I'd accidentally pulled any out I assume the car wouldn't start at all.

I only have a couple days before my daughters go back to college and I'm reduced to riding a bike to work. I may have to take the bug to a shop that will work on antiques.

kevin

[crvc]

Using a voltage meter I found the battery is 10 volts. Letting the bug run for a while does not increase voltage. I disconnected D+ and Df from the generator and saw no current while the engine was running. I talked to a mechanic who offered advice but couldn't see the car for at least a week.

I have three old generators. I don't remember how I got them but they're old and dirty and I think I kept them for spare parts. I took the generator out. A real PIA getting it out without unbolting the fan. Then I laid it on the bench next to the other three. I have a 12volt dry cell battery. I made sure it was charged. Then with jumper cables I put the negative on the shell and positive on D+. When I did that with the latest generator I got sparks. Then tried it with the 2nd and 3nd and got nothing. Then tried it on the last one and it started spinning. I put the positive cable on Df and it started spinning the opposite direction. I guess that means it works???

Since my daughters haven't left for college yet I made them help me get this generator back in. I started it and--viola!--the red light went out. So this one works--the oldest and dirtiest of the four--but it works I hope.

kevin

[Marc]

...I removed the fan belt. I put a jumper from Df to ground. Then ran a jumper from the battery positive to D+. Instead of the generator spinning I got a spark...

OK, so you've done the "polarization" A.K.A. tried to run the generator as a motor; nothing you did removing/installing the engine should've killed it (including the little spark-show) so unless it's dirty brushes it's apparently just a nasty coincidence.

Here's the procedure from Rob & Dave's, (same as you did already, just as confirmation):

Polarize the Generator -

...To polarise the generator, remove the fan belt, jumper wire from DF to the generator case (grounding the DF terminal). Now connect a wire from the + terminal on the battery to D+ on the generator. The generator should now start to spin. A few seconds is enough for this test.

If the generator doesn't spin, it's faulty. It's rebuild time (or at least it needs an auto electrician to look at it).

Now, note that you can do this same test on an uninstalled generator, all you need to add is a second jumper cable from the negative battery post to the housing of the generator. Wise to clamp it down so it doesn't jump out of your hands when power is applied.
A healthy generator will spin up and run smoothly as a motor when hooked up like this. Don't do it for too long as it could overheat, but ~10-20 seconds at a time won't hurt anything. If it just shudders, or rotates unsteadily, there's a problem with the commutator/windings and it needs the attention of a specialist.

Try bench-testing your extra generators, if they spin (and the brushes don't bounce up & down on an out-of-round commutator) they're worth the effort to install in the car.

[crvc]

Thanks, I tried it on all three and got nothing. I took apart the one that had been working before I removed the engine. I looked for obvious problems but didn't see any. The old one that's in and working also makes a screeching noise. With the belt off I can turn the generator by hand and don't hear any rubbing. But at idle something rubs. Or perhaps it's generator bearing noise?

kevin

[crvc]

I took half a day off work expecting I'd be removing the generator again. While listening with a stethoscope I found the noise was coming from sheetmetal rubbing the large pulley. I bent it away from the pulley a little and the noise went away. Since I had the time I went to work on the 6-month-old generator that quit working after I pulled the engine out. I took it apart completely and found a broken wire at the Df pole. I guess from unscrewing the nut multiple times I bent the wire enough to break it. I dug out tools and soldered the wire and put everything back together. Then using the dry cell and jumper cables I tested it and it runs great.

So now I have a good-as-new generator that I can use once that really old generator quits working.

kevin

[Marc]

Good work! There should be two nuts on the DF post, the bottom one is snugged down against the insulator to stabilize the "stud". If you always hold it with a thin second wrench while you're loosening/tightening the top nut against the terminal the stud shouldn't spin and break that wire loose.

Prior to mid`69, instead of posts for DF and D+ they used push-on terminals (so that's what your `67 harness had originally). It was better for DF, but sometimes had problems carrying the current at D+. "Best-of-both-worlds" is to keep the "bolt-down" ring terminal on D+, but add a push-on terminal (such as is found on ignition coils) to DF so you don't need to touch the nuts when removing/installing.

[crvc]

http://i1325.photobucket.com/albums/u63 ... 462d73.jpg

I put the generator together but forgot that small ring. It spins fine without it. Then I took it back apart and added the ring. Now it's too tight to spin using the 12volt dry cell. Can I live without the small ring?

kevin

[Marc]

Probably. It preloads the bearing, but I don't imagine anything would fail right away without it. But it shouldn't be causing that problem, makes me wonder if something else isn't quite right.