Alternator? Voltage Reg? No lights on dash

[vwzorm58]

Help!

I replaced the alternator and VR with a rebuilt unit from Pelican and when I got everything hooked up I have NO lights on the dash when I turn the key on. I hear the fuel pump (FI), and have headlights, clock, etc., but nothing on the dash. The car will start, but doesn't run smoothly like it usually does so I haven't run it for more than 20 seconds or so. When the car is running I get no tach, no volt-meter, no dash lights (not even alternator).

I tried the old VR and even tried a spare from my stash and have the same results. I have verified all connections (short of removing the rblt alt and checking the ones under the cover, but I know I plugged in the harness and the big wire that goes to the starter. My 3-prong wire harness is in excellent shape (replaced about 5 years ago).

The problems first began when I was driving the car and the alternator light came on. I drove the car home (15 miles at highway speeds) and turned it off. I then re-started it and it started OK, but the alternator light stayed on so I shut it off until I could replace the alternator. BTW, this is a car that has seen regular usage for the past 10 years and I've never had any electrical problems whatsoever.

Anybody have any suggestions why I get no lights, no tach, no volt-meter? Thanks in advance for any and all ideas - I'm stumped!

Mike g.
74 914 2.0

[Joe Sharp]

Hey Mike, the dash lights get their power form the light switch and they all have common ground. Grounds can cause real gost probablems with the electrial system. The gauges try to ground throgh each other and the dash lights. I would look at the gounds behind the dash and check common power terminals.
Oh and the Alt light needs to work if doesn't it won't excite the alt circut and you won't get charging.

[vwzorm58]

IT'S FIXED!

I wish I could claim some sort of earth-shattering discovery that fixed it, but alas I cannot. I checked, double-checked, and triple-checked everything I could and found nothing amiss. Finally, in a fit of anguish I started the car and ran it at about 3K RPM for about a minute and all of a sudden the gen-light came on! I let it run another 30 seconds then shut it off. Now all of the dash lights come on when I turn the key on and they go off when I start the car.

The only thing I can think of is that maybe the new/rebuilt alternator needed to be run at speed for a few minutes before it would start generating electricity and do whatever magic to the voltage regulator it needed to do.

Anyway, hopefully this little anecdote will help someone in a similar situation in the future. Thanks for all your warm wishes and sympathy - that probably had as much to do with it getting fixed as anything

[Joe Sharp]

So Mike, to quote Andy "things that fix themselve tend to un fix themselvs." Enjoy it while it lasts. If the issue come up again, just post again.

[Jared at Pelican Parts]

Check your battery connections/groundstraps. This sounds like a loose connection.

[vwzorm58]

(sigh) As Joe said, "things that fix themselve tend to un fix themselvs. Enjoy it while it lasts"

I put everything back together today (all the heat ducting, hoses, etc.) got cleaned up, and went out for my victory lap. Turned the key on and the gen and oil lights came on (yeah). Started it up and the gen and oil lights went off (yeah). Put it in reverse and the gen light came back on (sound of me crying in my beer).

Now the gen light comes on and stays on when the engine is running, but like before, no oil or gen light with the key on and the engine not running. No volt-meter activity on the console gauge either.

So I'm back to square-1 trying to figure this thing out. I've checked by battery connections and the tranny-chasis ground strap. I checked every connection I could find and everything looks OK.

I'm wondering: Could something have been damaged either on the circuit board or possibly the battery itself when I drove the car 20 miles with the gen light on (BTW the brushes had failed in the original alternator).

As before, any and all sugestions greatly appreciated.

[904svo]

Try cleaning up fuse #9 thats the power for the brake and gen light, instruments lights brake lights also.

[vwzorm58]

IT'S FIXED (again)!

Although I had already checked each fuse, at 914svo's suggestion I checked them all again. I used an OHM meter across the metal mounts for each fuse and they all checked good. Then I removed each fuse for inspection and lo and behold! #9 was broken (not blown) in such a way that the metal was MOSTLY making contact with the end of it. I supposed when I checked with the OHM meter I was pushing against the ends such that it made connection, but it wasn't a good enough connection to pass the voltage through it.

Just before I discovered this I was going over the schematics in my Haynes and had discovered that the brake lights, backup lights, wipers, volt-meter, oil and gen lights, and a few other things ALL run through that same fuse. I hadn't realized that none of the other components were working either since I was focusing on the gen and oil lights, but when I checked them a few minutes ago none of them worked.

BTW, in case any of you were wondering, the alternator really had gone bad. When I removed the cover to swap it to the new unit the brushes were rattling around inside of it. So somewhere along the way this fuse #9 coincidentally went bad at the same time. Weird, but there you have it.

Anyway, everything is working fine now. Thank you all again for the suggestions, thoughts, and warm wishes. Now if we can just get some warm weather here in Colorado I can drive it again

[Joe Sharp]

And you learned a lot about your car.