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Old 09-14-2007, 02:50 AM   #1
mexgrhd68
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Lightbulb what the heck?

allright fellas, I have a 68 pickup that seems to hate having its headlights turned on! The truck will sit in idle very good, but as soon as I turn the headlights on, the darn truck turns off!! I replaced my dimmer switch because I seen that the wires where it connects to the switch were melted, thinking this would cure my problem, but no way. Could it be the headlight switch? what do you guys think? think I need another alternator?
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Old 09-14-2007, 03:11 AM   #2
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Re: what the heck?

Sounds like it could be your voltage regulator and /or alternator to me. Alternator does not usually do that but it's possible if the regulator is bad.
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Old 09-14-2007, 04:28 AM   #3
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Re: what the heck?

Do the lights work? Both of them? What about when it's not running? Only at idle? Any idea what melted the wires on the dimmer?
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Old 09-14-2007, 04:36 AM   #4
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Re: what the heck?

You may be grounding out the ignition system somewhere. Like on some lawn mowers. Kill the switch it goes to ground and kills the engine. Melted wires are always suspect. I'm no mechanic, so I'm just guessing here.
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Old 09-14-2007, 05:16 AM   #5
72armyswbtruck
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Re: what the heck?

No Not The Dreaded Electrical Problems>>>>
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Old 09-14-2007, 08:03 AM   #6
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Re: what the heck?

My vote is a bad ground. Turn the key on (not start) and turn the headlights on. Does the ignition switch get hot?
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Old 09-14-2007, 03:16 PM   #7
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Re: what the heck?

Put a multimeter on the battery while it is running, if it is less than 13 volts, you have a charging issue.
That's my vote.
Keep it simple, electronics are not that hard.
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Old 09-14-2007, 05:30 PM   #8
mexgrhd68
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Re: what the heck?

Quote:
Originally Posted by Fe2o3 View Post
Do the lights work? Both of them? What about when it's not running? Only at idle? Any idea what melted the wires on the dimmer?
both lights work when truck is on or off, as far as the melted wires, don't know I don't think the dimmer switch ever been replaced.
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70 caddy 2 door, 89 chevy silverado stepside(older sons rides )
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Old 09-14-2007, 09:14 PM   #9
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Re: what the heck?

when the lights are on with engine running, then battery isnt used. The alternator must drag down for the load, if the regulator senses this it can kill the engine thru the red wire.

Wiring may be grounding or i vote regulator....
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