T18 reverse switch
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T18 reverse switch
Hello,
I have a 1989 F150 XL 4X4 with a 5.0 and the T18 transmission. 77k original miles, got the truck from my day when he passed. My reverse lights just stopped working so I looked underneath and the cable going to the reverse witch was zip tied off. My dad did not do anything to the switch as far as I know. The backup lights have been working until recently. I checked the fuse which was good.
Does anyone know if Ford used an alternate reverse switch setup vice using the switch off the tranny? It does not look like the tranny switch was ever used.
Appreciate any info anyone can provide. Thanks.
I have a 1989 F150 XL 4X4 with a 5.0 and the T18 transmission. 77k original miles, got the truck from my day when he passed. My reverse lights just stopped working so I looked underneath and the cable going to the reverse witch was zip tied off. My dad did not do anything to the switch as far as I know. The backup lights have been working until recently. I checked the fuse which was good.
Does anyone know if Ford used an alternate reverse switch setup vice using the switch off the tranny? It does not look like the tranny switch was ever used.
Appreciate any info anyone can provide. Thanks.
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With the T18 haveing internal shift rails and with the way the shifter fits into the transmission, it would be hyper-ugly to fit an external switch.
Here is a thread with a Ford illustration of the switch set ups for the 4 speeds.
https://www.ford-trucks.com/forums/1...ht-wiring.html
And a switch:
https://www.transmissionpartsdistrib...mazda-m5r1-72/
Here is a thread with a Ford illustration of the switch set ups for the 4 speeds.
https://www.ford-trucks.com/forums/1...ht-wiring.html
And a switch:
https://www.transmissionpartsdistrib...mazda-m5r1-72/
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From: Angier, NC
Take a test light to the wires. 1 should be hot all the time with key on and the other not.
Then jump the 2 wires together and the back up lights should work if everything is good.
This way you will know if it is a wire / light bulb or light socket issue OR the switch.
Dave ----
Then jump the 2 wires together and the back up lights should work if everything is good.
This way you will know if it is a wire / light bulb or light socket issue OR the switch.
Dave ----
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Jumpered the wires on the cables that were zip tied and not on the reverse switch. Put in reverse turned the key on and the jumper wire started smoking. The cable is not connected to the switch and has not been I think for a long time.
Am wondering if the first owner of the truck before my father somehow rigged the lights somewhere else? I pulled the bulbs and did a voltage check about 12 milli volts DC with the key on and truck in reverse.
I guess i am down to tracing wires and figure out where the reverse lights are wired up to. I know it is not the reverse switch on the tranny. Strange!
Am wondering if the first owner of the truck before my father somehow rigged the lights somewhere else? I pulled the bulbs and did a voltage check about 12 milli volts DC with the key on and truck in reverse.
I guess i am down to tracing wires and figure out where the reverse lights are wired up to. I know it is not the reverse switch on the tranny. Strange!
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FTE Legend
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From: Angier, NC
What side of the wiring was smoking?
1 wire is hot with key on and goes into the switch on the top shifter plate.
The other wire is out of the switch and goes to the back up lights out back.
If you pull the jumper dose the wire still smoke?
If not then I would say the short would be on the wire to the lights out back.
I would pull the bulbs and using an ohm meter see if that wire is shorted to ground, meter between wire & ground, you should not get a reading if it is not shorted.
If you get a reading you will need to trace the wiring from that point all the way to the rear lights.
I don't see how you could of had working b/u lights as there is no other switch.
Dave ----
1 wire is hot with key on and goes into the switch on the top shifter plate.
The other wire is out of the switch and goes to the back up lights out back.
If you pull the jumper dose the wire still smoke?
If not then I would say the short would be on the wire to the lights out back.
I would pull the bulbs and using an ohm meter see if that wire is shorted to ground, meter between wire & ground, you should not get a reading if it is not shorted.
If you get a reading you will need to trace the wiring from that point all the way to the rear lights.
I don't see how you could of had working b/u lights as there is no other switch.
Dave ----
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What side of the wiring was smoking?
1 wire is hot with key on and goes into the switch on the top shifter plate.
The other wire is out of the switch and goes to the back up lights out back.
If you pull the jumper dose the wire still smoke?
If not then I would say the short would be on the wire to the lights out back.
I would pull the bulbs and using an ohm meter see if that wire is shorted to ground, meter between wire & ground, you should not get a reading if it is not shorted.
If you get a reading you will need to trace the wiring from that point all the way to the rear lights.
I don't see how you could of had working b/u lights as there is no other switch.
Dave ----
1 wire is hot with key on and goes into the switch on the top shifter plate.
The other wire is out of the switch and goes to the back up lights out back.
If you pull the jumper dose the wire still smoke?
If not then I would say the short would be on the wire to the lights out back.
I would pull the bulbs and using an ohm meter see if that wire is shorted to ground, meter between wire & ground, you should not get a reading if it is not shorted.
If you get a reading you will need to trace the wiring from that point all the way to the rear lights.
I don't see how you could of had working b/u lights as there is no other switch.
Dave ----
The only thing I have not checked is the trailer hook up on my hitch.
I spent a few hours yesterday under my truck looking at wire bundles, nothing seems out of sort.
I am thinking that perhaps the connector came off the reverse switch and where it was sitting made it look like it was never connected.
I will look at my trailer hitch and check the wiring.
Then I will connect the cable back to the reverse switch and see what happens.
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Well my reverse lights are fixed. I think what happened is:
1. The cable came off the reverse switch so I am think my reverse lights have not been working for a while.
2. Second where the cable fell down, it looked like it had not been connected at all which led me down a trail of trying to figure out whether or not a mod to the reverse light was done.
Today I reconnected the cable to the switch and tried with no luck. Discovered my fuse had blown. So I replaced the fuse and I had a new reverse switch so I replaced that and reconnected the cable. I then disconnected my trailer hitch four pin connector and tried again, and my reverse lights are working. There is a short from the short pigtail to my trailer wiring connector on my rear bumper causing my fuse to blow. . I will leave that issue for another day.
I sincerely appreciate all the help and advice from this forum. I am glad it is working.
1. The cable came off the reverse switch so I am think my reverse lights have not been working for a while.
2. Second where the cable fell down, it looked like it had not been connected at all which led me down a trail of trying to figure out whether or not a mod to the reverse light was done.
Today I reconnected the cable to the switch and tried with no luck. Discovered my fuse had blown. So I replaced the fuse and I had a new reverse switch so I replaced that and reconnected the cable. I then disconnected my trailer hitch four pin connector and tried again, and my reverse lights are working. There is a short from the short pigtail to my trailer wiring connector on my rear bumper causing my fuse to blow. . I will leave that issue for another day.
I sincerely appreciate all the help and advice from this forum. I am glad it is working.
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