1962 gmc half ton no power to front lights - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bp81 · 05-09-2022, 08:05 PM

Back lights working front no power. Replaced lights. Ordered new switch in case that’s the issue. Suggestions welcome I worked on this thing all morning. Can’t figure it out.

**cwcarpenter98** · 05-09-2022, 08:45 PM

Have you checked various connections in the system with a multimeter?
I would start at the headlight plugs, if nothing there, check the connection at the core support, then check the connection coming out of the firewall, the headlight switch, and the power wire for the lights going into the fuse block.

I lost power to my headlights when the power wire on the back side of the fuse block corroded and came apart at the terminal. Replaced the terminal and all was good again.

**bhap** · 05-09-2022, 10:15 PM

Make sure you have a good ground in the front harness, then start chasing power wires. I think they are light green (high) and tan - tha tis what 62 Chevy are. They run from the dimmer switch to the main harness next to brake master on firewall to the rad support plug. There are a few wiring diagrams floating around..

TJ's Chevy · 05-09-2022, 10:48 PM

I'll 2nd a good ground. Seems 9 times outta 10 it's a grounding issue on this old iron.

Wrenchbender Ret · 05-09-2022, 10:54 PM

Check the dimmer switch & connector. They are in a position to get corrosion. 9 times out of 10 that is the problem with that symptom. The connector is available as a pigtail from part stores.

George

AcampoDave · 05-10-2022, 09:51 PM

Maybe its losing contact at the firewall bulkhead connector

cgrocen · 05-11-2022, 01:01 PM

I echo the statement of those above who say a good ground is very important.
Once you ascertain a good ground, then get out your test light and start checking for power. I would probably start at the headlight switch. Since you have power to the back lights, then you know you have power up to your switch. Make sure the pointed end on your test light is good and sharp to pierce the insulation on a wire. Start working your way to the front. You may want to check any wire connector plugs first. There can be corrosion there. I recently chased some wires on a 1959 Ford F100 and found wires where the insulation looked good but the wire was broken inside. I also found where the insulation was worn away, and the wire shorted out, melted, and the connection was broken. This may be a long shot too, but is there any chance that the lights may simply be burnt out? Let us know what you find.

05-09-2022, 08:05 PM	#1
Bp81 Registered User Join Date: Apr 2022 Location: CA Posts: 2	1962 gmc half ton no power to front lights Back lights working front no power. Replaced lights. Ordered new switch in case that’s the issue. Suggestions welcome I worked on this thing all morning. Can’t figure it out.

05-09-2022, 08:45 PM	#2
cwcarpenter98 Senior Member Join Date: Jan 2018 Location: Hickory Flat, GA Posts: 4,496	Re: 1962 gmc half ton no power to front lights Have you checked various connections in the system with a multimeter? I would start at the headlight plugs, if nothing there, check the connection at the core support, then check the connection coming out of the firewall, the headlight switch, and the power wire for the lights going into the fuse block. I lost power to my headlights when the power wire on the back side of the fuse block corroded and came apart at the terminal. Replaced the terminal and all was good again. __________________ Christian Carpenter 1963 C10 - Frankentruck 283, Muncie 3 speed with overdrive Overdrive wiring here 1963-ish truck bed trailer - Half-Wit 1981 C10 - Penny 305, th350 --> Soon to be 350, Saginaw 4 speed 1995 Dodge Dakota Sport "I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson

05-09-2022, 10:15 PM	#3
bhap Senior Member Join Date: Mar 2006 Location: Pittsburgh, PA Posts: 266	Re: 1962 gmc half ton no power to front lights Make sure you have a good ground in the front harness, then start chasing power wires. I think they are light green (high) and tan - tha tis what 62 Chevy are. They run from the dimmer switch to the main harness next to brake master on firewall to the rad support plug. There are a few wiring diagrams floating around..

05-09-2022, 10:48 PM	#4
TJ's Chevy Registered User Join Date: Mar 2013 Location: Southern Oregon Posts: 10,384	Re: 1962 gmc half ton no power to front lights I'll 2nd a good ground. Seems 9 times outta 10 it's a grounding issue on this old iron. __________________ 1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw

05-09-2022, 10:54 PM	#5
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: 1962 gmc half ton no power to front lights Check the dimmer switch & connector. They are in a position to get corrosion. 9 times out of 10 that is the problem with that symptom. The connector is available as a pigtail from part stores. George

05-10-2022, 09:51 PM	#6
AcampoDave Registered User Join Date: Feb 2013 Location: central California Posts: 2,783	Re: 1962 gmc half ton no power to front lights Maybe its losing contact at the firewall bulkhead connector

05-11-2022, 01:01 PM	#7
cgrocen Registered User Join Date: Apr 2017 Location: Esterhazy, SK Posts: 82	Re: 1962 gmc half ton no power to front lights I echo the statement of those above who say a good ground is very important. Once you ascertain a good ground, then get out your test light and start checking for power. I would probably start at the headlight switch. Since you have power to the back lights, then you know you have power up to your switch. Make sure the pointed end on your test light is good and sharp to pierce the insulation on a wire. Start working your way to the front. You may want to check any wire connector plugs first. There can be corrosion there. I recently chased some wires on a 1959 Ford F100 and found wires where the insulation looked good but the wire was broken inside. I also found where the insulation was worn away, and the wire shorted out, melted, and the connection was broken. This may be a long shot too, but is there any chance that the lights may simply be burnt out? Let us know what you find.



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