Back-up Light Switch Question
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5th Gear
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Back-up Light Switch Question
Hi! I have a 1974 F100 3 speed truck I'm trying to get going.
I'm trying to figure out if my switch is bad or is something wired wrong.
I have a pretty simple question concerning the back-up light switch. Is it supposed to be complete the circuit when the plunger is depressed (reverse lever pushes it), or does pushing in the plunger supposed to break the circuit?
Right now my reverse lights are on when in neutral,1-3, but turn off when put I it in reverse. Seems like it should complete the circuit when the plunger closed. If the switch did the opposite of what it's doing, I would be fine.
I'm trying to figure out if my switch is bad or is something wired wrong.
I have a pretty simple question concerning the back-up light switch. Is it supposed to be complete the circuit when the plunger is depressed (reverse lever pushes it), or does pushing in the plunger supposed to break the circuit?
Right now my reverse lights are on when in neutral,1-3, but turn off when put I it in reverse. Seems like it should complete the circuit when the plunger closed. If the switch did the opposite of what it's doing, I would be fine.
Last edited by GeorgeAFTRLF; Aug 13, 2024 at 03:45 PM. Reason: type of truck
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From: Angier, NC
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I would say when it is pushed but from what you are saying it dose not work that way so I am not sure
Easy enough to check how many wires going to the switch?
Remove them. If 2 wires check if one had power with key on and are the lights on?
Then jump the wires together and check the lights, do they now come on?
If so you would want a normally open switch when in 1-3 and closed when in reverse.
If 1 wire it may ground that wire but check for power first before grounding.
If no power with key on and no lights ground the wire do you have lights?
If so just like above normally open in 1-3 and closed to ground when in reverse.
you can check the switch with a ohm meter.
See if it is a normally open (at rest) or normally closed (at rest)
It should change when you press it.
Dave ----
I would say when it is pushed but from what you are saying it dose not work that way so I am not sure
Easy enough to check how many wires going to the switch?
Remove them. If 2 wires check if one had power with key on and are the lights on?
Then jump the wires together and check the lights, do they now come on?
If so you would want a normally open switch when in 1-3 and closed when in reverse.
If 1 wire it may ground that wire but check for power first before grounding.
If no power with key on and no lights ground the wire do you have lights?
If so just like above normally open in 1-3 and closed to ground when in reverse.
you can check the switch with a ohm meter.
See if it is a normally open (at rest) or normally closed (at rest)
It should change when you press it.
Dave ----
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Joined: Feb 2004
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From: The Shenandoah Valley
Hi! I have a 1974 F100 3 speed truck I'm trying to get going.
I'm trying to figure out if my switch is bad or is something wired wrong.
I have a pretty simple question concerning the back-up light switch. Is it supposed to be complete the circuit when the plunger is depressed (reverse lever pushes it), or does pushing in the plunger supposed to break the circuit?
Right now my reverse lights are on when in neutral,1-3, but turn off when put I it in reverse. Seems like it should complete the circuit when the plunger closed. If the switch did the opposite of what it's doing, I would be fine.
I'm trying to figure out if my switch is bad or is something wired wrong.
I have a pretty simple question concerning the back-up light switch. Is it supposed to be complete the circuit when the plunger is depressed (reverse lever pushes it), or does pushing in the plunger supposed to break the circuit?
Right now my reverse lights are on when in neutral,1-3, but turn off when put I it in reverse. Seems like it should complete the circuit when the plunger closed. If the switch did the opposite of what it's doing, I would be fine.
If Automatic, the neutral safety switch and back up light switch are combined and mounted on top of the steering column well under the dash, Back up lights on in neutral, not reverse .... reads like the switch needs adjustment.
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5th Gear
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Sorry - it's a manual.
Is it a manual ... or ... automatic transmission?
If Automatic, the neutral safety switch and back up light switch are combined and mounted on top of the steering column well under the dash, Back up lights on in neutral, not reverse .... reads like the switch needs adjustment.
If Automatic, the neutral safety switch and back up light switch are combined and mounted on top of the steering column well under the dash, Back up lights on in neutral, not reverse .... reads like the switch needs adjustment.
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5th Gear
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Thanks for the reply!
It is two wire. There is power when the key is in the on position. The button works OK, except it's doing the reverse of what I need.
When the truck is any gear besides reverse, the button on the switch is out and the lights are on.
When the truck is in reverse the shift rod pushes up on the button (as I believe it should) and then the lights go off.
Grounds at the lights lights are untampered with OEM and there is continuity. Everything else works.
Easiest solutions would be to get a switch that does the opposite of what it's doing right now, but I don't know if that's an option. Maybe the wrong switch is in there?
It is two wire. There is power when the key is in the on position. The button works OK, except it's doing the reverse of what I need.
When the truck is any gear besides reverse, the button on the switch is out and the lights are on.
When the truck is in reverse the shift rod pushes up on the button (as I believe it should) and then the lights go off.
Grounds at the lights lights are untampered with OEM and there is continuity. Everything else works.
Easiest solutions would be to get a switch that does the opposite of what it's doing right now, but I don't know if that's an option. Maybe the wrong switch is in there?
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5th Gear
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From: The Shenandoah Valley
Looking at the picture, it appears it could only be contacted by the 1-R lever coming out of the column in any event ... and since you only want the lights on in reverse when the lever is "up", it would follow that the switch needs closed circuit when depressed then. I looked the switch up on RA, looks like it's a generic pushbutton switch with just two screw terminals.
Reads like yours is busted up inside and a piece is fell out of place and shorting contacts when relaxed or "button out" .... and the piece is out of place when the button is pushed inwards? Such damage would be easy to have with age, heat, maybe adjusted too close or maybe fast shifts from N up to R?
Reads like yours is busted up inside and a piece is fell out of place and shorting contacts when relaxed or "button out" .... and the piece is out of place when the button is pushed inwards? Such damage would be easy to have with age, heat, maybe adjusted too close or maybe fast shifts from N up to R?
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5th Gear
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Looking at the picture, it appears it could only be contacted by the 1-R lever coming out of the column in any event ... and since you only want the lights on in reverse when the lever is "up", it would follow that the switch needs closed circuit when depressed then. I looked the switch up on RA, looks like it's a generic pushbutton switch with just two screw terminals.
Reads like yours is busted up inside and a piece is fell out of place and shorting contacts when relaxed or "button out" .... and the piece is out of place when the button is pushed inwards? Such damage would be easy to have with age, heat, maybe adjusted too close or maybe fast shifts from N up to R?
Reads like yours is busted up inside and a piece is fell out of place and shorting contacts when relaxed or "button out" .... and the piece is out of place when the button is pushed inwards? Such damage would be easy to have with age, heat, maybe adjusted too close or maybe fast shifts from N up to R?
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