Stonea's Charging Issue

[stonea]

I'm trying to diagnose my battery charging issue that I've been having. Hopefully I can organize this thread to help other people out too in the future. I'll Keep on updating the first post on my testing and findings.

Background: I'm not an expert on this stuff, I've been working on cars for a while now, but I don't have much experience diagnosing things, and it doesn't help that electricity has never been my strength

Problem: My car has always had a charging issue. It could probably go two weeks and the battery would die. To me this sounded like something was on the fritz since it wasn't constant. I could go 2 weeks, hell sometimes even a month and be fine. Now it seems like something is just down right broke, the alternator doesn't charge the battery at all. I can have the car fully charged via battery charger and I could probably kill the battery in a day if I tried.

Symptoms:
-Alternator Light in the SI board is on when the key is in the "ON" position and is still on after you start the car, but it is VERY dim and goes away after I give the engine just a little bit of gas. ABS light also does this as well.

-Battery doesn't charge. I use a battery charger to charge it outside the car and once I put it in, its only a matter of time until I have to swap it out again.

New Parts:
-Refurbished 150 Amp Alternator (eBay)
-Refurbished Gauge Cluster (Bavarian Restoration)
-Upgraded Power and Ground Cables (Bavarian Restoration)
-Used, but working 1.3 Motronic ECU (eBay)

Have you checked voltage with the car running?

Voltage Test:
Fully charged battery fresh off the charger - 13.07 v
Said battery hooked up to car - 12.99 v
Car on and rev'd a couple of times - 12.55 v
Lights on - 12.36 v
High beams on - 12.29 v
Car turned off after test - 12.69 v

[Cephas]

Have you checked voltage with the car running?

[stonea]

Voltage Test:
Fully charged battery fresh off the charger - 13.07 v
Said battery hooked up to car - 12.99 v
Car on and rev'd a couple of times - 12.55 v
Lights on - 12.36 v
High beams on - 12.29 v
Car turned off after test - 12.69 v

Edit: Updated first post to be more helpful

[audiquattrot]

did the issues arise after you replaced the cluster?

[stonea]

The charging issue was around before the cluster swap, but was never real bad. I replaced the cluster with the one from Bavarian Restorations and no real change, but then sometime later it got a lot worse.

[Fsnow]

Has the same alternator been in the whole time you have had these issues? Ebay alternator would likely be the culprit if everything is hooked up properly and the belt is turning the alternator. You should have around 14.4 volts when it is running.

[Cephas]

Voltage Test:
Fully charged battery fresh off the charger - 13.07 v
Said battery hooked up to car - 12.99 v
Car on and rev'd a couple of times - 12.55 v
Lights on - 12.36 v
High beams on - 12.29 v
Car turned off after test - 12.69 v

Edit: Updated first post to be more helpful

You are not getting a charge from your alternator at all. This could be a few things - but I would start with the easy things first:

1) Is your "Battery Light" on at all in the cluster? Does it light up when you turn the key to the ACC position?
2) Do you have all the proper engine grounds in place and clean?


Other possibilities are a bad alternator or brushes/voltage regulator. But I would start with the cluster light bulb. If it's dead, the car will not charge.

[stonea]

Has the same alternator been in the whole time you have had these issues? Ebay alternator would likely be the culprit if everything is hooked up properly and the belt is turning the alternator. You should have around 14.4 volts when it is running.

I've had two different alternators, one that came with the car that I replaced after I started having serious battery charging issues then I swapped it out with the rebuilt one and there has been no change.

You are not getting a charge from your alternator at all. This could be a few things - but I would start with the easy things first:

1) Is your "Battery Light" on at all in the cluster? Does it light up when you turn the key to the ACC position?
2) Do you have all the proper engine grounds in place and clean?


Other possibilities are a bad alternator or brushes/voltage regulator. But I would start with the cluster light bulb. If it's dead, the car will not charge.

Cluster bulb is brand new from ECU tunning. It turns on when the key is in the ACC position, and once you turn the car on it goes very dim until you give the car some gas. I don't know if thats normal or not. Also cleaned all the engine grounds and got rid of the grease and dirt when I replaced the cables.

I'm thinking about trying to pick up a working alternator from a trusted forum member and also another gauge cluster. I need a gauge cluster for a school project anyway.

[audiquattrot]

I have an alternator laying in my garage, but shipping might be $$

[Cephas]

You have both alternator wires connected, right?

Do you get battery voltage at "D+" terminal on the alternator? This should be with the car off (not running), but the key in the "Acc" position.

[stonea]

I have an alternator laying in my garage, but shipping might be $$

Well if it comes to it, I might jump on it.

You have both alternator wires connected, right?

Do you get battery voltage at "D+" terminal on the alternator? This should be with the car off (not running), but the key in the "Acc" position.

Just ran out and tested this it reads 4.32 v

[Cephas]

Well if it comes to it, I might jump on it.



Just ran out and tested this it reads 4.32 v

Now we're getting somewhere. This should show battery voltage. I would trace that wire back and make sure that there are no breaks. I'm not sure where that wire starts, but I would check the Electrical troubleshooting manual to see where it gets its power from and start there.

[stonea]

Now we're getting somewhere. This should show battery voltage. I would trace that wire back and make sure that there are no breaks. I'm not sure where that wire starts, but I would check the Electrical troubleshooting manual to see where it gets its power from and start there.

Ok now that something is actually wrong I feel a little bit better. I'll look into this and try to trace the wire and see if anything is wrong with it.

Thanks guys!!!

[Cephas]

Ok now that something is actually wrong I feel a little bit better. I'll look into this and try to trace the wire and see if anything is wrong with it.

Thanks guys!!!

Just looked at the ETM (Electrical Troubleshooting Manual) and that blue wire runs back through the C101 and is also connected to your ABS control unit (which would explain why your ABS light is on as well). I would actually start at the C101 connector. Open it and clean it/make sure that no one made any shade-tree repairs to it. If you don't find anything there, I'd start to lean towards the cluster being the culprit, since the charge signal originates there. As a quick test, I would replace the battery charge bulb for grins to see if it helps.

What year is the car? BTW, this could all still be the alternator in the end. I know you've replaced it, but if the charge diode in the exciter circuit is shorted, it could be pulling your exciter wire (blue wire) voltage down and also causing the alternator to not charge.

Good luck!

[stonea]

Ok so I've still been chasing this down. And I've noticed that my alternator light in the cluster is on, but VERY dim when I have the key in the on position but not running. Everyone I have talked to says that I probably got a bad alternator or something. Did another voltage test though.

12.80 v Battery Fresh off the Charger
12.73 v Battery Connected to the Car
12.70 v Terminal on the Alternator that goes to the Starter
00.00 v D+ Terminal on the Altenator
08.76 v D+ With the Car in the "On" Position but not Running
12.38 v Battery with the Car Running

I'm taking the car into a shop to get the head gasket replaced and I'm getting them to replace some plugs and other things while they got the engine apart. Should I get them to put in a new engine harness too? Theres one on eBay for $200. I don't want to take it to a shop, but the car just sits there and between school and work I barely have time to even go check to see if there car is still in the garage let alone to actually work on it.