Door Jam switch replacement
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5th Wheeling
Joined: Nov 2023
Posts: 26
Likes: 3
From: Tennessee
Door Jam switch replacement
Hi all. Tried finding the answer before posting so forgive me if this is redundant.
Im replacing the door jam switches in my 77 f100 Custom Explorer. I ordered and received the switches and pigtails to do both sides, the issue is the part being replaced is 2 wire and the new pigtail has three wires. Is that an additional ground? I understand how the switch works with constant power and ground triggering the dome, just have no idea if I can disregard the third wire.
thanks in advance,
Keith
Im replacing the door jam switches in my 77 f100 Custom Explorer. I ordered and received the switches and pigtails to do both sides, the issue is the part being replaced is 2 wire and the new pigtail has three wires. Is that an additional ground? I understand how the switch works with constant power and ground triggering the dome, just have no idea if I can disregard the third wire.
thanks in advance,
Keith
Fleet Mechanic
Joined: Feb 2022
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The door switches on my 73 have three wires. One is ground, one is feed from the fuse panel, and one is switched power to the dome lamp. Perhaps the design changed in later model years and you received parts from the earlier models? Others will have to weigh in here because I’m not well educated enough on what might be different.
Fleet Mechanic
Joined: Feb 2022
Posts: 1,366
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This is what I ordered as replacements. LMC shows all of the model years sharing the same parts.
https://www.lmctruck.com/1973-79-for...-jamb-switches
https://www.lmctruck.com/1973-79-for...-jamb-switches
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5th Wheeling
Joined: Nov 2023
Posts: 26
Likes: 3
From: Tennessee
Thank you, viper. Yes, that is the exact part I bought from LMC along with the switch itself. It’s odd to me that there’s three wires but I do know it comes from the harness which comes from the fuse block so the 3rd wire on the 77 would be unnecessary. No?
Logistics Pro
Joined: Oct 2006
Posts: 4,025
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From: East Central Ia
Same switch and plug used for several models 3rd wire could trigger headlamps on module or others.
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Fleet Mechanic
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Great thread on dome light wiring. Pretty much all you'll need to know about dome light wiring. You don't need to ground the switch. I didn't know that but I'm glad you started this thread because now I do. The ground for the cargo light and the dome light is in the roof support brace under the headliner. The door switch is a 12V power supply that gets shorted when the door is closed (switch depressed).
https://www.ford-trucks.com/forums/1...00-1973-a.html
https://www.ford-trucks.com/forums/1...00-1973-a.html
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5th Wheeling
Joined: Nov 2023
Posts: 26
Likes: 3
From: Tennessee
Great thread on dome light wiring. Pretty much all you'll need to know about dome light wiring. You don't need to ground the switch. I didn't know that but I'm glad you started this thread because now I do. The ground for the cargo light and the dome light is in the roof support brace under the headliner. The door switch is a 12V power supply that gets shorted when the door is closed (switch depressed).
https://www.ford-trucks.com/forums/1...00-1973-a.html
https://www.ford-trucks.com/forums/1...00-1973-a.html
Fleet Mechanic
Joined: Feb 2022
Posts: 1,366
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FYI, if the old switches look different than the new ones you received this thread will help explain why. Self adjusting to your door. Kinda cool.
https://www.ford-trucks.com/forums/1...tch-wtf-2.html
https://www.ford-trucks.com/forums/1...tch-wtf-2.html
Thread Starter
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5th Wheeling
Joined: Nov 2023
Posts: 26
Likes: 3
From: Tennessee
FYI, if the old switches look different than the new ones you received this thread will help explain why. Self adjusting to your door. Kinda cool.
https://www.ford-trucks.com/forums/1...tch-wtf-2.html
https://www.ford-trucks.com/forums/1...tch-wtf-2.html
thanks!
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5th Wheeling
Joined: Nov 2023
Posts: 26
Likes: 3
From: Tennessee
I haven’t touched mine yet but will be installing soon. Just got my New Vintage USA gauge cluster so I’ll be buttoning up all behind the dash wiring at the same time. Thanks again for your help.
5th Wheeling
Joined: Jul 2023
Posts: 31
Likes: 7
From: Seattle
I spent some time yesterday cleaning up the door jam switches and am curious to get some thoughts and guidance. I removed the switches and got out the wire brush and some sandpaper and was able to clean the 3 little prong contacts pretty well. The other side was harder to get to due to the plastic collar. Any tips on how to get in there? It's the dome shaped area that the 3 prongs contact when the switch is moved out (when the door would be open).
Overall I got things working pretty well (once I got past the cramp in my thumb from holding the switch down
when the switch is removed but when I installed it and tightened it down, it only works intermittently. I'm thinking that tightening things is twisting the switch a bit and changing contact points. I loosed the nut a bit and that helps some. Any thoughts on guidance on this will be helpful as well.
Overall I got things working pretty well (once I got past the cramp in my thumb from holding the switch down
when the switch is removed but when I installed it and tightened it down, it only works intermittently. I'm thinking that tightening things is twisting the switch a bit and changing contact points. I loosed the nut a bit and that helps some. Any thoughts on guidance on this will be helpful as well.
More Turbo
Joined: Oct 2023
Posts: 549
Likes: 240
From: Anacortes
I replaced mine recently and same deal, one came from O'Reily's and one from LMC cause I forgot to order 2. Both were exactly the same.
Mine was a 2 wire setup originally and I think I just metered the leads off the new switch to find the two needed on the new switch and just capped the other 3rd wire.
Easy peasy.
Mine was a 2 wire setup originally and I think I just metered the leads off the new switch to find the two needed on the new switch and just capped the other 3rd wire.
Easy peasy.
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TheViper90210
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