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Old 10-22-2003, 04:46 PM   #1
jeffbo
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HELP: Electrical Problems

Not really sure where to post electrical problems, so I guess I'll just do it here. Anyway, I can't get my truck to start today. I was having electrical problems last week. I would attempt to start my truck and there was nothing at all. No click from the starter and the dome light wouldn't even light up at all, as if there was no power at all. I messed with the battery connections a little and my dome light would come on, but as soon as I turned the key the dome light went out and nothing happened again. So I repeated the process, jiggling the battery cables until my dome light came on and turning the key. Eventually I got it to start after a dozen tries. Drove to the parts store and picked up a new negative battery cable, assuming it was the problem. Installed the cable and the dome light came on instantly, a good sign. Turned the key and nothing. Messed with the new cable some until the dome light came back on, turned the key and she started. So I figured it was the battery, since it was old anyway. I installed a new battery and everything seemed fine. The truck worked perfect all weekend for me. Then today, I drove to work. After work I went to start it and the starter clicked once, the dome light died, and that was it. It is doing the exact same thing as before. I attempted to jump start it and that didn't work. Something I noticed today that I didn't last week is that while I was sitting in the truck with the door open attempting to start it, the dome light slowly comes back on within about 1 minute after turning the key. Once I turn the key it immediatly goes out. After I release the key I watched the dome light and it just faintly glows and slowly gets stronger, like it is gaining power. If I turn on something electrical, such as the headlights, the dome light goes out, but the headlights still won't come on. It's like they don't have enough power. I hope this makes some sense to you guys, kind of hard to explain it. So any suggestions? All I can come up with right now is possibly the starter solenoid. Would it cause the truck to do this? I'm going to try to test it with a test light ASAP. How do I go about this. Do I just connect the light to the 2 posts on the solenoid and have someone turn the key or what? Or could the problem be something else? I just hope it's not a short somewhere in my wiring harness. I would appreciate any suggestions. Thanks.
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Old 10-22-2003, 04:57 PM   #2
bpmcgee
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Have you checked the battery voltage when the truck won't start? It sounds to me like your battery is dead.

That would mean either:

1) Defective battery (possible)
2) Defective charging circuit (i.e. alternator or v. regulator)
3) Slow drain someplace.


Any of these, I believe, would cause the symptoms which you describe.

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Old 10-22-2003, 05:02 PM   #3
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tell you what happend to me one time. on my little 4 banger toyota. the positive cable had started to come loose from the actuall battery cable connector. It was not off all the way but was coming loose. My car woudl do same thing. lights go dim then out. I replaced alternator, battery and then one day while *****ing @ it I noticed the + was feeling wiggley. sure nough.. That was it I replaced with with a new cable connector and never had a problem sence.

my 2 cents. hop eit helps. ( but probally not ) :-)

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Old 10-22-2003, 05:08 PM   #4
jamis
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I think the best thing is to start over.

1. Load test your batt., if it fails then you might have a draw thats killing the batt. To check for a draw, first turn everything off in your truck disconnect your negative cable from the batt. and place a test light between the negative batt. post and the negative cable. If it lights up then you have something drawing down the batt. If you have an amp. meter, it will work better then a test light.

2. If the batt is ok. now test your cables by either doing a load test at the starter positive lug and the ground lug on the engine block. Or you can do a similer test by using a volt meter in the same location and watch the voltage drop during a cranking cycle. It should not fall below 10 volts. If it does you have bad cables, bad conection at the cables, or a shorted starter thats drawing to many amps.

3. If that is ok, then jump the positive lug on the stater to the "S" post on the starter. Make sure your truck is in neutral and the emergency brake is on!!!!!!!!! If that turns your engine over then look for the problem in the ign. key circuit.

Try that first then let us know, I or someone else will walk you threw the next steps.
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Old 10-22-2003, 05:20 PM   #5
tom hand
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Check your connection to the terminal block next to the battery...If it is not getting power there nothing inside the truck will work
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Old 10-22-2003, 05:38 PM   #6
jeffbo
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I "tested" the battey by arcing a pair of pliers across the posts and it had very good spark. Damn near welded the pliers onto the battery. It's probably not the best or most accurate way, but I'm pretty sure the battery is fully charged.
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'68 C-10 4spd (not running)
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Old 10-22-2003, 06:23 PM   #7
cdowns
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replace the +cable, if that works cut the insullation off it and look at the condition of the wire it's probably all green and nasty
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Old 10-22-2003, 06:40 PM   #8
jeffbo
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Hey, I just got the truck started and feel kind of stupid now. It was a simple problem. The positive batt cable was extremely corroded under the screw. I should have checked it right away, but I guess I didn't even think of it because the truck ran fine all weekend, and the + cable is only about six months old, so I didn't even consider it as a possiblility. Just goes to show you should always start from the first step and not get ahead of yourself. I'm glad this was the problem and it wasn't more serious. Thanks for all of the very prompt replies though. I appreciate it.
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'72 C-10 LWB Highlander, A/C, tilt TH350 w/ B&M shift kit, 327LJ bored .040", cast flattops, forged crank, L31 Vortecs, 9.25:1 CR, Comp conical valvesprings, Crane Energizer single pattern 216/.454", Professional Products Power Plus Crosswind intake, Edelbrock #1406 600cfm, HEI, dual exhaust, open 3.08 12bolt
'68 C-10 4spd (not running)
'79 C-10 LWB Mild 350
'80 Caprice Classic, 2-dr
'97 GMC K-1500, SWB, Reg. Cab, Z-71, 5.7, Auto
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Old 10-24-2003, 12:44 AM   #9
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It sounds like you have a high resistance connection. If you have a multimeter, measure the voltage at the battery. Note the voltage. Next measure from the positive terminal to the frame. Note the voltage. Next measure from the negative terminal to the poitive on the solenoid. A fully charged lead acid battery should measure 13.2 Volts. If your ground, and positive cables are good all three measurements should be the same. After you get those voltage measurements we can go on to step two. On a side note I wouldn't suggest using the wrench across the battery terminals as a way to measure the health of a lead acid battery. That's a really good way to have the battery explode in your face. Not good.
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