912E Electrical Problem

Shawn Erwin · 10-26-2004, 09:18 PM

I just picked up a 912E and I have a bit of a electrical problem. The car was sitting with a dead battery and I replaced it. Now there are two issues...(1) both turn signal lights in the dash stay lit when the car is running (turn signals work fine). (2) headlights dim quite a bit when engine returns to idle. Can anyone point me in the right direction for troubleshooting?..

Thanks in advance,
Shawn

david c. · 10-26-2004, 09:58 PM

1. bad ground somewhere in the lighting circuit. Follow it around and clean the connections or, better, get a wiring diagram and track it down. There is probably a 912E wiring diagram around here somewhere. The turn signal circuit might be identical to a 76 911 but I'm not sure.

2. did you trickle charge the battery or just jump start? If the latter, it might take a little while to recharge the battery (assuming it will in fact take a charge and hold it). Best bet and cheap insurance is to go and buy yourself a new battery (get a sealed one, like an Optima) and have the alternator tested. It's fairly easy to remove, clean the terminals, have it tested, reinstall with a new belt. All cheap insurance with a "new" 30 year old car.

Enjoy!

Nige-912E · 10-27-2004, 01:04 AM

Shawn

I'll be interested how you fix the signal lights in the dash, mine does the exact same thing with the actual turn signals working fine. I just assumed it was down to some dodgy left over wiring as it had an UNGO box fitted (ancient immobiliser/alarm) which I have since removed.

Its been one of those things that has never really bothered me enough to fix, probably because of more important things to fix

Nige

Shawn Erwin · 10-27-2004, 07:56 PM

Thanks...I will try out your suggestions and I'll tell you how they worked out...I'll also post a decent picture when I get a chance.

Rich Roesch · Rich Roesch's Garage

I have this same problem with my turn signals and have chased everything as well as tried several different turn signal flashers. Each of those give me some different and incorrect symptom. So I just accept that my indicators stay on all the time but do flash with the turn signal when selected. Anybody fixed this yet?

COLDBASS · 11-13-2004, 09:14 AM

BTDT - Had a new switch installed and that cured the prob.

Dave C. (as always) is right on with his comments...

The problems I had when chasing electrical woes on the 944, were that when troubleshooting I was using old/used electrical parts. This was adding different symptoms/gremlins to the original issue...YMMV

Good Luck, keep us posted...

Oh, yeah...one more thing. I had individual relays installed after the H4 installation...dont ask, some folks have to learn the hard way...

Shawn Erwin · 11-13-2004, 03:47 PM

OK....After driving the car for awhile I smelled battery acid from the front of the car. I soon discovered that the charging system was over charging the battery to the tune of 16.5 volts! I replaced the voltage regulator and problem fixed. 14.5 volts and no dimming lights..good to go...All so had a successful smog test too...woohoo!

Turn signals still on...I'm going to live with it.

Nige-912E · 11-15-2004, 03:29 AM

Quote:

Originally posted by Shawn Erwin
OK....After driving the car for awhile I smelled battery acid from the front of the car. I soon discovered that the charging system was over charging the battery to the tune of 16.5 volts! I replaced the voltage regulator and problem fixed. 14.5 volts and no dimming lights..good to go...All so had a successful smog test too...woohoo!

Turn signals still on...I'm going to live with it.

Me too, I first changed the regulator, still overcharged, removed and repaired the alternator (4 times, long story) still overcharged. After much head scratching I found that the ali cage that the regulator is attached to wasn't earthing properly, so the regulator couldn't regulate!! 5 minutes with abit of emery paper over the mouting points and problem solved. Took me two weeks to get to this fix!! typical.