1985.5 Porsche 944 Charging Issues

9fourfour · 03-05-2012, 06:04 PM

I have a 1985.5 porsche 944 that is having some charging issues. The altenator is not putting out any voltage at all, So I replaced the altenator with a rebuilt unit from Napa. The car still does not charge however. I did pull what looked like an aftermarket alarm our of it and this seemed to be when this all started. There were a couple of wires that ran across the firewall, crimped several times, one being tied to the ignition coil, the other to the battery and what appeared to be an aftermarket alarm box self tappered to the firewall. Just to rule out the alarm, I jumped the stock porsche alarm module to rule it out and the car still won't charge. I pulled the intstrument cluster out as well and I cam across a porsche wiring diagram that shows a ciruit that runs through the cluster that goes to the regulator. Even though the diagram does show a bulb, I cannot find one in the cluster for the charging system other than the voltmeter gauge. I'm at my wits end on this car, I love the car, but its driving me crazy. Does anyone have any ideas? Any better wiring diagrams than those on all data and shopkey?

snake1996 · snake1996's Garage

Check out CLARKS-GARAGE.com Very helpful website

Outback Porsche · 03-07-2012, 02:27 AM

Quote:

Originally Posted by 9fourfour

I pulled the intstrument cluster out as well and I cam across a porsche wiring diagram that shows a ciruit that runs through the cluster that goes to the regulator. Even though the diagram does show a bulb, I cannot find one in the cluster

That bulb is behind the battery symbol on the dash. If that bulb is dead, your battery will not charge. Does the battery light come on when you turn the ignition key to the ON position?

9fourfour · 03-07-2012, 03:37 AM

I've been to Clarks Garage, def a great resource

Not that I've noticed, but I don't see a bulb behind the battery symbol. I've heard that the late model 944's don't have a charging light even though one appears on the wiring diagram. Do they have one? The euro wiring diagrams are confusing as all hell.

CatsEyes · 03-08-2012, 02:54 AM

A PO installed an aftermarket immobiliser on my 944 of the same vintage as yours. Did it himself, judging by the big clumsy dollops of solder.

He re-wired the ignition circuit to go back through the immobiliser.

He also opened and tampered with the ignition relay to suit it to the new wiring layout.

It took me forever to sort all this out.

Have you thought about restoring the alarm and returning the wiring etc to its previous state? Just to see if that's the issue?

Good luck.

9fourfour · 03-08-2012, 01:28 PM

wow, that sounds like a nightmare! To tell you the truth, I don't remember how any of the wiring I took out went back in, and I don't know it I have all the pieces. I'm one of those anal people who when they buy a car has to eliminate every ounce of hack job that has ever gone into it, and with this porsche, it looks like a lot unforunetly. I'm going to try just jumping 12 volts to the d+ terminal and see if it puts out more current. It turns out the altenator is charging, but only like 12.7 volts at the most, so just not enough.

CatsEyes · 03-09-2012, 04:27 PM

Yes, I think there's a common story with a lot of these cars (it's certainly true of mine):

1. First 15 years of their lives owned by well-heeled purists who always serviced them at Porsche workshops, and washed them more than they drove them

2. A subsequent decade of ownership by cash-strapped home-mechanics who tried to do everything themselves, working with whatever tools they had to hand, and cutting out wiring circuits when things went wrong.

3. New owners, bewildered by the effects of 2., who sign up to this forum looking for help. (Again, people like me!)

Good luck. I've had similar alternator issues myself, though not quite as bad as yours. I feel your pain!