Author Topic: Battery light :( (Read 4817 times)

VW Scully · « **on:** October 12, 2007, 06:42:36 pm »

Hey everyone;
On my way home tonight, I was stuck in a traffic jam on the freeway, and my battery light came on, but when I revved the engine, it went out again.
I've just had the alternator brushes replaced but I'm wondering if it's dying somewhere else :roll:

I do recall in my old Bug, the battery light would flicker if the car was idling/stuck in traffic for a long time. Could the 2 things be related?
Once I got moving again, the light stayed out.
Any help!? :?:

Patrick · « **Reply #1 on:** October 13, 2007, 04:11:54 am »

First thing I'd be checking is belt tension/belt slippage. I've had serious trouble on SOME of these cars keeping the belt tight enough. Maybe there's too much wear on the alternator pulley? There's always the possibility of a bad ground somewhere too, but I think you went looking for that before you did the alternator...........

jtanguay · « **Reply #2 on:** October 13, 2007, 04:28:20 am »

my alt keeps loosening up too. i just re-tighten and re-tighten. oh well just one of those things i suppose. maybe need some locktite on the adjusters...

BlackTieTD · « **Reply #3 on:** October 13, 2007, 07:12:38 am »

especially if its a new belt it will loosen up as the belt stretches out. try retightening it and see if the problem returns. i have had similar things happening with my '82, but i know for a fact the v-belt is really sloppy right now (about 6000km since i put a new one on, no re-tighten yet). so i just assume thats what it is on mine. could also have something to do with voltage regulator which is about a $20 part you can change with a screwdriver.

jimfoo · « **Reply #4 on:** October 13, 2007, 08:11:25 am »

Also could happen if the belt is old and glazed.

subsonic · « **Reply #5 on:** October 13, 2007, 03:48:04 pm »

Does the light come on real low at highway speeds? You may need to drive at night to notice. Mine was like that. Bearing in the alt was worn out and sloppy. It allowed some internal "drift" , and a no or low charge situation. Just a thought.

VW Scully · « **Reply #6 on:** October 13, 2007, 04:40:24 pm »

Thanks guys;
I had wondered if it was slipping again. I had tightened it before I had the brushes replaced, but of course, had to take the Alternator out to take it to the reubild shop and haven't tightened the belt again since I put the Alt. back in.
It was night time actually when I was driving home, and so easy to see the dash lights.
Light would go out completely once I revved the engine and got out of the traffic jam and back up to 100 - 110km/h.
Car goes into storage in 2 weeks, but I wanted to address this ASAP so I'm not stuck somewhere.

I had such a ***ty day on the job yesterday too, I felt like my Rabbit was mad at me cuz I bonked into another car in the parking lot on set. :oops: sigh; it's always something! :roll:
Anyway, I will try tightening the belt tomorrow and see what happens! Thanks everyone!

Vincent Waldon · « **Reply #7 on:** October 13, 2007, 05:36:28 pm »

How did the commutator look when you replaced the brushes ??

The last couple alternators I've worked on the commutator was worn as well as the brushes... in this case just replacing the brushes only works marginally... if at all.

blkboostedtruck · « **Reply #8 on:** October 13, 2007, 06:50:24 pm »

you prolly should do a VAT40 check on your charging system any garage can do that maybe your local parts store can do the test as well? i know they do it here in the states! thats to see how much your Alt. is puting out! and it will tell you what is actually worn out ! hope that helps ?
thanks Duane

jtanguay · « **Reply #9 on:** October 14, 2007, 04:41:19 am »

my money is on tightening the belt.

my batt light goes on and tach dies when i'm just running the rear defogger and the fan at speed 3. when i choose speed 4 on the fan, it occurs intermittantly and only at idle. it really really pisses me off!

lol a funny story... I changed my main accessory belt one day, and put everything back together... no problems and everything is cool. then i'm driving down the road and i hear a clang on the road (metal hitting pavement) so i thought hmmmm no oil trail so i'm good to go. then my batt light and tach go nuts. intermittantly coming back on and nice screeching from the belt slipping on the pulley. turns out the bolt that holds the alt on managed to wiggle itself out :shock: i thought my alternator was dying... put another bolt in and bingo good as new... except for the belt tensioning issue.