Author Topic: Electrical issue  (Read 23706 times)

Offline 355shortbed

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Re: Electrical issue
« Reply #15 on: August 06, 2011, 02:25:14 AM »
Yes the fuse only blows when the engine is running after it is started, this is the3rd ditributor in the truck it is a MSD street fire H.E.I distributor  we tested voltage at the fuse Monday and after the engine started the voltage at the fuse was at 13 volts then jumped up to 15 volts. Could a bad coil cause this problem?

Offline griffo2k

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Re: Electrical issue
« Reply #16 on: August 07, 2011, 01:03:08 AM »
it should jump to around 15 volts the alternator should be regulated at 14.8 volts you should be more concerned about current. current takes the path with the least resistance. so you need to check for shorts to ground or a failing component on all the run side of the ignition switch like Greg says.
« Last Edit: August 07, 2011, 01:06:38 AM by griffo2k »
1983 GMC Sierra Clasic 1500

Offline VileZambonie

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Re: Electrical issue
« Reply #17 on: August 07, 2011, 10:50:54 AM »
The starter is not your problem. Go back to my last post and find your problem. You either have a chaffed wire or pinched wire in the bellhousing or something grounding that circuit. A Fuse is not going to work. Replace it with a fusible link once you find where it's shorted. It should be fairly easy since it's such a short lead from the junction block.


http://forum.73-87chevytrucks.com/smforum/index.php?topic=11972.0
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 355shortbed

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Re: Electrical issue
« Reply #18 on: August 29, 2011, 10:39:53 PM »
sorry to bring this topic back up but the other day i found somthing rather odd. i was tinkering with the wiring, ihad charged my battery up the night before. i unplugged the charging wire on the back of the alternator and started the engine up and let it run for a bit. after 5 minutes i took it up the road and noticed the engine running better than it had since i had installed the engine and it started fouling spark plugs every week. my point being is before unhooking the charging wire from alternator my plugs where all black and sooty and becoming fouled by too much fuel, and after unhooking that wire and driving the truck around the plugs have cleaned up to a nice chocolate color and the motor has come back to life and is driving great, the battery is not getting charged by the alt. but as long as it is above 12 volts the plugs stay where they need to be.       Why?

Offline txchainsawgogi

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Re: Electrical issue
« Reply #19 on: August 30, 2011, 11:19:05 AM »
that really is weird.

Offline 1980c10

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Re: Electrical issue
« Reply #20 on: August 30, 2011, 04:45:09 PM »
My best guess;
Check the voltage to your electric choke with and without the alt hooked up with the engine running. My guess is that some how you're losing voltage to your choke not allowing it to open completely.  If the voltage increases to your choke with the alt disconnected that is the issue.

Offline VileZambonie

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Re: Electrical issue
« Reply #21 on: August 30, 2011, 08:55:10 PM »
Is the B+ stud on the alternator loose? Sounds like either the B+ is touching the case or it's time to replace the alternator.
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              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 355shortbed

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Re: Electrical issue
« Reply #22 on: August 30, 2011, 09:11:50 PM »
Well I just got a new alternator Saturday and I ordered a new engine wiring harness from classic parts. Hopefully it will work out .  Wat I dnt understand is why it ran so poorly for about a year fouling plug after plug and all I changed in the equation was unhooking that wire and runs like it should , pretty odd. Guess it got tired of siting in the yard lol