I have an '86 5000 TQ wagon, and have develloped a charging problem.

While driving the car, it bagan to shut down electrical componants - Radio, guages etc. I got the battery light on the dash, and then the car died. I was able to limp it home, at which point found that the battery was dead. I charged it over night, and now the car starts with no problem. But I am not convinced that there is no alternator issue here. After running the car for a few minutes, the battery will still take a charge from the charger. That tells me the alternator isn't charging..... right?

How can I test to see if the alternator is good or not?

What else could it be?

The PO said that both the Alternator and battery were relatively new, but I have no reason to believe that was the case.

Thanks!

 

Sounds like the brushes are worn down. Remove the alternator and pull the brush/regulator assembly it's one piece and replace it. RockAuto has them for $30. I had a similar problem on my SAAB that also uses a very similar Bosch alternator.

 

Thanks for the tip Offramp.

I started the car and put a meter across the alternator, and it was just 12.5V - and falling. So I am confident that the alternator is finished.

I'll see if any of the local parts places sell regulator/brush assemblies. Otherwise I'll visit the local scrap yard.

 

The alternator is located in a bad spot without any protection. Yesterday I was driving in some heavy rain and all of a sudden my radar detector started to chirp with low voltage warning. I looked at the voltage gauge and with the engine running it was reading about 10-11V. Either the belt was slipping or the alternator took in too much water. Time to pull my the alternator apart.