Alternator light and no gauges

[L Sjoberg]

On my way home labor day weekend my alternator light came on (dimly) and several of my gauges acted up - I had no voltmeter, no turn signals or brake lights, and my gas gauge, oil temp and tach registered only nominal activity. B/c I was about 120 miles from home, I putzed home and swapped out the voltage regulator (thanks Pelican). Still same problem.

Should I go ahead and swap out the alternator? What about an alternator belt (these fail every now and then on my 911)? And where do I find the belt (it doesn't jump out at me)? The battery doesn't seem to be running down, as I am still able to start the car (just w/o gauges). I just went through a "ground cleaning" and new battery exercise, so I'm pretty confident that I don't have an earth strap or battery issue.

Thanks!

[John Rogers]

We had something similar to this on our 914 coming back from getting the body work and paint done and I really had some panic too. Oh yes, when I put on the brakes, everything (guages) got worse! I read on the Renegade site to check the fuses and I did and the 4th from the right was blown. It was turned around and you couldn't see it right away. When I replaced it, all worked fine again!

[This message has been edited by john rogers.]

[JP Noonan]

Similar thing happened to on I-95 on a sweeping on ramp (had nothing to do with catching up to a new M3 just to show off). At about 75-80 MPH the engine died, nothing worked except the alt light (it was bright). Hazards, radio, lights, nothing. So I pulled over and for some reason undid the batt. (paranoid) and as I looked up from the engine bay saw smoke from under the center console. It seems a PO had bypassed the interlock relay with an open faced terminal block (I should have butt spliced everything as soon as I found it but..) that shorted out the electrical system. Even though I had fused the three wires from the batt. (2 smaller wires 20amps each, 1 thick wire with 2 30 amps in parallel) only one of the fast blow 30amps blew the other looked like it was about to. Anyway before pulling the alt. test the system with a volt meter. Dave Darling posted a detailed procedure a few months back. I'm sure if you look (or ask him nicely) you'll find it. I would guess it is either a fuse (don't just check them, take each one out, use emery cloth on the ends of the fuse and the fuse holder) or check the ground point above the fuse block. If that dosen't work, pop out the gauges and make sure nothing is shorting out. In a 25 year old car a lot of rewiring happens for CB's, radios, alarms, and most of it is left dangling (the worst in my car was a hot +12V wire taped up with masking tape, that fire is another story).

[Wayne 962]

I had my alternator go out on me about a year and a half ago. I was up in Hollywood at night (about 20 mi from home). I drove home, and at about 2 miles from my house on the freeway, I could here the injectors clicking, but there was no spark. So, I shut off my lights (driving home at 2AM in the morning, can we say 'Cop-bait'). As soon as I did this, the car took off! I guess it had a whole bunch of unexploded fuel to burn.

Anyways, the car made it to my driveway. I got out to open the garage door, and it died. I consider myself lucky, otherwise, I would have had to count that as a 914 breakdown (I'm at 2 AAA tow calls right now for the 914 and one for the 356 when I left my tire iron in my garage and got a flat. *stupid, stupid, stupid, as I'm still beating myself up for that one*)

Anyways, if the belt were failing, the light would probably go back off as you rev'ed the engine. Most likely it's the diodes. Check out the following diagnostic procedure for alternators:

http://www.pelicanparts.com/914/914QA/914Q_electrical_alternator.htm

Hope this helps,

Wayne

[L Sjoberg]

Well, just like w/ the 911 I'm learning something new about 914's...every time something goes wrong w/ the darn thing!!!

Thanks for the help - turns out the gauge fuse was bad. It looked good, but I swapped it out anyway and everything's back to normal (a relative term). The symptoms John explained were identical. Hope I can return the favor and help someone else out...