1972 Chevy C10 with a 350 hei conversion harnesses alternator not charging and when key off engine still runs

80

Asked by Nov 10, 2016 at 06:33 PM about the 1973 Chevrolet C/K 10

Question type: Car Customization

1972 Chevy C10 with a 350 hei conversion harnesses alternator not charging and when key off engine still runs.

12 Answers

63,305

Sounds like the coil wire from the ignition switch is not hooked up correctly. Double check that. HTH. -Jim

80

Ok this is under the hood of the truck I'm working on this is how it came in

1 out of 1 people think this is helpful.
80

More pics

1 out of 1 people think this is helpful.
80

This wire was hooked up to the generator. It's the power wire from the distributor I ran it threw the firewall.

1 out of 1 people think this is helpful.
80

More

1 out of 1 people think this is helpful.
63,305

Standard GM from that era has the power going from the starter, to the ignition switch, then from there a resistor wire to the distributor. The resistor wire is there to drop down the voltage from 12 VDC to 6 to 8 VDC. The "BAT" terminal on the back of the alternator is supposed to be connected to the positive (+) battery cable on most GMs of that era. Do you have an external voltage regulator? HTH. -Jim

80

Yes that got replaced

1 out of 1 people think this is helpful.
63,305

Sounds like the wiring to the distributor is hot all the time. You'll have to rewire the system correctly. When you shut off the ignition, you're actually cutting off power to the ignition coil which shuts off the engine. If the wire going to the ignition coil is hot all the time, the engine will keep running. HTH. -Jim

1 out of 1 people think this is helpful.
80

Do you think I'm better off rebuilding the harness. As I was looking at the whole truck today most of the harness inside and out is cut spliced and what not.. I think he is also missing some ground wires.

1 out of 1 people think this is helpful.
63,305

If it's that bad, yes. You can get wiring diagrams from the factory shop manual. Try eBay or Faxon Auto Literature in Riverside, California. They have a website. There's also companies that make reproduction wiring harnesses out there. A Google search should help you find one. On a truck of this vintage it shouldn't be too hard to do the wiring. Did you find out where the wire from the alternator goes? The fuse box? HTH. -Jim

80

Nothing was hooked up to fuse box is what I found out... hence I already got the manual for the truck... hopefully I get most of the wiring done Monday I'll let u know how it gose thanks for the help

1 out of 1 people think this is helpful.
63,305

Ok, sounds good. Having the manual is a must. The wiring should be pretty straight forward. Yes, please keep us posted. -Jim

Your Answer

Add photo

Related Questions

  • 55 Chevy 3200 6v to 12v in progress, 350 swapped.

    OK so I swapped in 350 w/ automatic. I have engine on stand alone setup, is carbureted, HEI distributor. So 12v alternator & battery, I want to run the 6v systems off the 12v charging, I re instal...

    1971 Chevrolet C/K 10

    -

    Car Customization

  • Fuel Tank 6 answers

    I have 1972 c10 with 1989 stepside bed installed. I'm a 350/350,650 Holley,12 bolt rearend 373 gears. I want to use the existing fuel door on the stepside, whta fuel tank should I use with the mechani...

    1972 Chevrolet C/K 10

    -

    Car Customization

  • 1989 c10 1 answer

    Ok first I'm ah let you know that I got bad gas from ah friend and it was 85% water yep all went in my tank & carb but nun the less I got most out drove the truck home it cut off ah frew times but...

    1979 Chevrolet C/K 10

    -

    Car Customization

  • Can I Install Small Block V-8 in 1965 CHevy Pickup 9 answers

    What I would like to do is remove the inline six in my 1965 Chevy Pickup and install a Small Block or Big Block V8. I have a three on the tree and would like to keep that in place. Is there any V8's t...

    1965 Chevrolet C/K 10

    -

    Car Customization

  • My 1972 350 shuts off randomly going down the road. After a few mins it will start up again and run fine....then do it again. 20 answers

    I just had the carb redone, new fuel lines and a inline filter. It has a HEI distributor for over a year now.

    1972 Chevrolet C/K 10

    -

    Maintenance & Repair

C/K 10

Looking for a Used C/K 10 in your area?

CarGurus has 1 nationwide C/K 10 listings and the tools to find you a great deal.

Postal Code:

Search Chevrolet C/K 10 Questions

Chevrolet C/K 10 Experts

#1 CaptPKelly
CaptPKelly
Reputation 560
#2 Rowefast
Rowefast
Reputation 310
#3 John Carson
John Carson
Reputation 300
View All

Related Models For Sale

Used Chevrolet Camaro
975 listings starting at $13,995
Used Chevrolet Blazer
17 listings starting at $3,999
Used Chevrolet Corvette
432 listings starting at $27,950
Used Ford Mustang
996 listings starting at $4,995