Dsqr964

Well, read through the forum here and can not decide if the cold solder joint could be the issue, the battery now (loaned my charger to my nieghbor and he is not around), or some other grimlin.
Original Issue: Engine light and ABS light both come on with no battery light but the voltage at the battery while car is running was 12.3V. Could charge battery for short hop for diagnostics of alternator or other needed driving but the battery slowly depleted as the charging system was not giving a charge.

Fix: Replaced alternator after testing it in car and giving low output. Had new alternator on shelf (2 1/2 years old never used still in box ordered when replaced fan bearings).

Out come: Ran great, improved performance for two weeks, now the same light configuration comes on Engine and ABS light with only 9.5 to 9.8 output at battery.

Any ideas out there? Battery could be bad but would that cause the experianced symptoms?
Thanks all, hope this is just a matter of manual labor to fix or very little expense as I am laidoff and my independant computer work is slow.

thanks again for any words of wisdom.

mojorizing

This post might be helpful, the clock, the blue wire....
https://rennlist.com/forums/964-foru...uestion-2.html

Dsqr964

Thanks Mojorizing, I went through the thread. Will need to reread tomorrow and start a little T/S with wiring and maybe a cold solder joint could be part of the issue after all, though I do get all dash lights when system is energized before starting engine.

Second issue will be getting into the engine compartment fuse box as someone before stripped out one of the cover bolts. Ah the joys of going in after the heavy handed.

BTW Mojorizing, I have loved your avitar pic ever since I have been part of this forum. Take care Sir.
-D²

Dsqr964

Ok did the test of Pin 11 to ground with the key energized, found that the alt light comes on, now the issue I have is that this is a new alternator that I have had on the shelf for the past two years. I have a hard time believing it would belly up on me after only two weeks of driving.

I will be pulling it and taking it to a shop to test along with my old alternator. Perhaps it is good and the issue lays somewhere with the "blue wire."

Testing output at the battery while running only shows a constant 12.35V so the alternator is definately not producing the charging Voltage required.

Any further thoughts would be much apreciated.

-D²

ras62

It is worthwhile checking to see if there is any load on the battery with the ignition off. Disconnect the negative lead and put a test meter in series to check for current drain.
Also you could swap relay 11 for the horn relay (sorry I cant remember the number) and see if it fixes the problem. I had all sorts of problems due to a dry joint in the 11 relay, all now solved. Good luck!

deadon

Remove the clock and resolder the connections on the rear. This will fix the alternator problem and the idiot lights on the clock. The solder cracks over time. If you do not have the skills there are plenty of gauge repair people that will be happy to do the fix.

Lorenfb

Many seem to forget that there're wires that connect the alternator's output
from the back to the battery in the front, and there is an intermediate connection
point at the starter. Wouldn't it be logical to check the voltage first directly at the
alternator or a close point before assuming it's bad?

Dsqr964

Thank you all for the advice.
Game plan: Check load on battery.
Try the relay switch.
Check the voltage at the starter connection.
Check the connections for the alternator
Then I will look at soldering the clock. Used to burn my own circuit boards as a kid so fairly handy with an iron, just not looking foward to taking the clock apart, thus it is the last thing on the list.

Thanks again for your advice, will keep you posted.

-D²

Lorenfb

"Then I will look at soldering the clock."

A waste of time if the light comes 'on' when the key is in the 'run' position and
the engine hasn't started. Once the engine starts, the light will go 'out'. The light
just helps 'start' the alternator to charge and doesn't affect it once it 'starts'.

Dsqr964

/agree.
The blue wire/ pin 11 test shows that the fault should not be the clock. That is why it is the last in the list.

After reading the link Mojorizing posted for me I discounted a clock issue. I am going to be testing the output at the starter connection for the true output of the alternator. Thank you for that insight on the starter connection.

Didn't work on it today needed to do desk work and work my network for jobs and contract work. Again I really apreciate this forum and all the members here as DIY Porsche owner. Hell I couldn't own one if I didn't do my own work. Learned alot on a 77' 911S Targa but there is plenty of advancemts on the 964 example which really endears me to the model. Really have no desire to drive anything else now.
I even load her up to go the SCA events as pictured in my sig.

-D²

p.s. My last job we had UPS driver who really liked my girl and was in the market for something different, he was used to BMW's and I told him to look around and take a P-Car for a drive. He bought a 993 will dig up a pic of our girls together. He told me he wouldn't have got one if he hadn't known me. We now have become friends because of our cars. It's cool how a machine such as ours can bring people together in a positive manner. Sorry I am meandering. -D²

Indycam

I would suggest you do the clock 1st . Its not a hard job and its a known failure / problem .
Solder it up real nice and then do the tests .
If it does nothing you still have a clock that has been soldered real nice and that will keep the clock from being a problem down the road for a bit , iykwim .
Think of it as preventative maintenance at worst and a hail Mary fix at best .

Dsqr964

OK, this is what I have done and results:

Verified that there is no drain on battery.
Tried the Relay 11/horn relay switch- no change in lack of out put.

Well with Indycam's input I looked at the car and thought ok get up off the ground, remove plastic trany cover, dig around with the meter at the starter or just pull the clock, unhook a few wires, go back to my desk, do a little solder work while drinking a cup of tea and still be clean.

I checked the clock out. A few posts gave flakey readings on the post itself vs the solder at the back. Reworked the solder with a veriable iron, used 25 watt to desolder the 3 leads for the clock itself, 30 watts to rework the post connections, messured and actually made one worse , used 35 watts and reworked. Mesured and all contacts now read good.

Replaced and no chage. Expected result honestly but did kinda cross my fingers.

Now to the starter: Made mesurements with car off and running, votages were the same 12.34 +-.03.

Next step verify the contiunuity of the "blue wire"- tested good.

So now with the alt out of the car I will be taking it in for testing as well as the old one.

If it is bad I hope that I can make a pheonix out of two piles of ashes.

-D²

-nick

I went through several "rebuilt" Bosch alternators until I found one that worked. I've seen threads with similar experiences from others. That would be my first line of attack.

FeralComprehension

I had my stocker rebuilt by a known-good local source to avoid the aforementioned issue.

Dsqr964

Well after looking arround here in Vancouver/Portland area could only find one shop that could test a Bosch alternator for a Porsche. Really!!

Will take and rig up a test bench in my meager garge just to test output to make me happy.

As Nick and FeralCompreHension stated I may just have a bad rebuild and I will look for a local rebuild shop. Surely there will be one here in my area .

I am tempted to try makeing a good one out of the two I have but I did find one for 149.00 and only a 60.00 core deposit.

Now for just my piece of mind: Is there something in the set up that could knock out the Alt that I have over looked?

Thanks for all your insight guys!

-D²