I was driving my 85 pickup this weekend and the charge/brake light came on for about 10 seconds. I checked my battery and everything seem to be okay. Later that evening I went for a drive and the lights came on again for about 5 seconds, This time I could see my headlights go dim. My guess is the alternator is going out. Should I be looking at something else?

 

alternator!

many threads on this subject

 

thanks metalhed.

 

Mine was the volt regulator. I replaced the alt like everyone said and it still happened.

 

i think 85's had internal regulators. have it tested, i bet its the brushes easy and cheap fix.

 

loose battery cable or plug on alternator.

 

Looks like I need ot do some DD before I start replacing the alternator. Nothing has been what is suppose to be lately with this truck.

 

yep .. I'd lay money on the alt. brushes as well ... I have done easliy a dozen of em ..


sometimes if you have been in the mud , it'll pack the brushes and they wont contact the armature causing a fault in the charge system .. sometimes preasure washing the alt will help loosen the packed brushes and free them up ..

 

thanks slacker. I'll give that a try first. I think the mechanic who replaced the steering pump might have got trans fluid inside the alternator.

 

oil leak will cause it as well ... try spraying some "enigne shampoo" and pressure washing it ..

 

Is it possible that a short somewhere else can cause the same outcome? (not trying to complicate matters with another possible suggestion....) The reason I bring this up is sometimes I hear a spark behind my instrument panel. I have the same problem as you and it only seems to happen when I first start up my truck (usually for the first 5 minutes or less) then the volt meter goes up to the top (I have a SR5 cluster int he truck.)

If it was the brushes wouldn't it be something that happened all the time and not just after initial start up? Night time is different and sometimes it take cruising the truck at about 40-50mph to get it to take a constant full charge when the lights are on!

John

 

worked for me ...


My p/s pump was leaking .. drip drip.. right on to the alt .


brake and charge lamp came on . I did the shampoo , and wash .. and maybe , just maybe then , the key is to LET DRY .


works perfectly even a year later . just my experiance .

 

Just a quick note to follow up and say that my problem is related to AT fluid in the alternator on the cables and connectors. I wiped off a bunch with my hand Saturday and that seem to fix the problem temporarily. I'm going to use a degreaser/engine cleaner spray on it this weekend.

And for clarification this problem didn't exist until the power steering pump ws replaced.