Chevy truck electrical

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  #1  
Old 12-09-08, 02:41 PM
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Question Chevy truck electrical

2 hours away from home, I started my truck last evening and noticed my lights were very dim. Then I noticed my battery gauge was only around 10. Other gauges were moving/jumping. Gradually (45 minutes) the battery went down to the red zone and I did not have lights.

I pulled off the road and suddenly my engine revved on it's own for about 5 seconds. I was about to turn the engine switch off when the revving stopped and just like that I had headlights again and the battery gauge went to 14. Did not have the problem the rest of the way home which was an hour and 15 minutes.

Any idea what it could be?
 
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Old 12-09-08, 07:44 PM
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almost sounds like a stuck brush in the alternator, how many miles on the vehicle?

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Old 12-09-08, 07:46 PM
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electrical

Since it cured itself I would look for bad connections in the batt cables or alt wiring. Check the ground wires that bolt beside the thermostat housing. RW
 
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Old 12-09-08, 09:36 PM
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forgot one often overlooked item, check for corrosion between the battery bolts and the cable inside of the insulation it is an area that is often overlooked when cleaning the battery cables and will cause electrical problems.

Murphy was an optimist
 
  #5  
Old 12-10-08, 06:32 AM
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Thanks for the replies!

The truck has 123,000 miles but the alternator has about 40,000. I checked all connections and they appear tight and clean. I'll take them apart and go over them to make sure.

Any idea why it revved high on it's own for about 5 seconds?

Another possible clue ... In the last 2 months, I don't drive this truck often, I have noticed when I start it the head lights and instrument panel lights will pulse bright-dim-bright-dim.

Thanks again!
 
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Old 12-10-08, 07:42 AM
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you most likely have a ground problem with the added info, disconnect all grounds and clean each one then reconnect firmly. some will be difficult to find, don't ignore dash grounds as they can affect your engine control computor.

are you going to cowboy up or just lay there and bleed?
 
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Old 12-10-08, 09:01 AM
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Originally Posted by Sam77 View Post
Thanks for the replies!

The truck has 123,000 miles but the alternator has about 40,000. I checked all connections and they appear tight and clean. I'll take them apart and go over them to make sure.

Any idea why it revved high on it's own for about 5 seconds?

Another possible clue ... In the last 2 months, I don't drive this truck often, I have noticed when I start it the head lights and instrument panel lights will pulse bright-dim-bright-dim.

Thanks again!
The alt. has 40,000 miles. Was it a NEW one or a reman? Maybe the built in regulator is malfunctioning? Just a thought.
 
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Old 12-10-08, 09:24 AM
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Had this happen on a Cutlass years ago....lights getting dimmer and dimmer. If I turned on the air conditioner and giving the electrical system a jolt I guess, it would start charging again.

Turned out to be a bad trio-diode (I think it's called) in the alternator. Cheap fix back then.


Baldwin
 
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Old 12-10-08, 09:40 AM
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Checked my records ... this alternator has about 25,000 miles. Paid $115 over 3 years ago. Delphi ... not sure if it's a reman.
 
  #10  
Old 12-10-08, 03:21 PM
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Smile

Just wanted to give a shout out to say THANK YOU for the suggestions and help you've given me! You guys are great and I appreciate the extra effort and thought.

I'm hoping this was a one-time event.
 
  #11  
Old 12-10-08, 07:28 PM
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electrical problem

[
Turned out to be a bad trio-diode (I think it's called) in the alternator. Cheap fix back then.


Diode trio,you had it but just backwards,thats the rectifier that converts AC to DC. The older ones you could fix pretty easy. These new ones arent made to repair.Where you used to have terminals now they are welded joints and you have to cut them apart and re solder the joints. The parts are so delicate if you bend them too much they just break off. Sorry I just got done with one and had to rant a little. RW
 
  #12  
Old 12-11-08, 12:48 PM
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Question

Anyone know where I can find the dashboard grounds? My instrument panel lights still are flickering bright-dim-bright-dim.
 
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