Interior light, open door switch

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casey3115

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Hi all. I have a 1977 c10. My interior light works fine if I click the headlight knob to the left but does not come on when the door is open. Neither door turns it on actually.
Anyone have a wiring schematic for these circuits? Or any ideas where I should start?
Thanks in advance.
 

bucket

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There's a plunger switch in each lower A-pillar. The switches usually just get crusty and can no longer complete the light circuit because of it.

If you unscrew the door jamb switch, you can unplug the white wire and ground it out. That should turn on the dome light. If so, simply replace the switch.
 

casey3115

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There's a plunger switch in each lower A-pillar. The switches usually just get crusty and can no longer complete the light circuit because of it.

If you unscrew the door jamb switch, you can unplug the white wire and ground it out. That should turn on the dome light. If so, simply replace the switch.
Sweet! Thanks. That's an easy place to start.
 

Blue Ox

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Be sure that the plunger doesn't turn while you're unscrewing the switch body. If it does you'll twist up the wire.
 

CorvairGeek

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I may be showing my age here, but if we are talking a very base model Custom, does it have door switches for the courtesy lights? I can remember when they did not.
 

bucket

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I may be showing my age here, but if we are talking a very base model Custom, does it have door switches for the courtesy lights? I can remember when they did not.

You may be on to something here. I had a very base model '79 K5, it may not have had the door jamb switches. I can't remember for sure.

But I know that even the upper trim level Burbs and crew cabs of the 70's did not get switches for the rear door jambs.
 

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I may be showing my age here, but if we are talking a very base model Custom, does it have door switches for the courtesy lights? I can remember when they did not.

Ha! My base model 82 C10 doesn't even have an interior light! I have a couple under dash fixtures I plan to install when I rewire the truck.
 

gmachinz

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You may be on to something here. I had a very base model '79 K5, it may not have had the door jamb switches. I can't remember for sure.

But I know that even the upper trim level Burbs and crew cabs of the 70's did not get switches for the rear door jambs.
My loaded 1990 Suburban didnt have rear door jamb switches either-until I re-wired the entire truck then I added my own rear door jamb switch circuit.
 

bucket

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My loaded 1990 Suburban didnt have rear door jamb switches either-until I re-wired the entire truck then I added my own rear door jamb switch circuit.

Well that's an odd one. I've had two 86's, an '88 and a '90, they all had switches in the rear jambs. The '90 was even the base Scottsdale trim, although with power windows and locks.

I added the rear switches to my '79 crew cab right after I bought it.
 

casey3115

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Be sure that the plunger doesn't turn while you're unscrewing the switch body. If it does you'll twist up the wire.
That is a good thought. I'll look out for that.
 

casey3115

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Both doors have them.
I may be showing my age here, but if we are talking a very base model Custom, does it have door switches for the courtesy lights? I can remember when they did not.
 

PrairieDrifter

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Well that's an odd one. I've had two 86's, an '88 and a '90, they all had switches in the rear jambs. The '90 was even the base Scottsdale trim, although with power windows and locks.

I added the rear switches to my '79 crew cab right after I bought it.
My 84 burban didn’t have rear door jamb switches either, manual locks and windows but is a Silverado. Then I added some myself to the rear while replacing the fronts as well
 

SquareRoot

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My 85 Custom Deluxe K20 doesn't have jamb switches or a dome light. I always thought the Custom Deluxe title was a little misleading. Maybe could have been
"Nothing, none, nada ****" package.
 

42Grand

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I found a wire while I was ripping out my single cab interior. I'm thinking it has something to do with the cab light but I don't have a door plunger in my truck. This connector was just hanging out by my drivers side seat belt. It ran along the sill plate, under the carpet and up into the fuse panel. Any idea what it is guys??
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crpntr78

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That should be the wire that hooks to to your seatbelt to send a warning buzz that your seat belt isn't buckled. Also should have a dash warning light that says seatbelt. Of couse with it not being connected you won't hear the buzz but you should still see the seatbelt light.
 

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