When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So... this is my last electrical problem (I think). 1975 F250.
Reverse lights don't work. Found the Reverse light switch (pictures below) but no harness anywhere. Can someone explain in detail where this harness is coming from? Just need to know it's location and routing so I can find what a previous owner did with it. Thank you.
Added a few pictures of the highboy updated. Getting close!!!
I don't have any pictures of that particular harness, but look under the hood on the driver's side splash pan. There will be a small "L" shaped connector with two wires going to it. This is where the back up light harness should plug into the main harness. On automatic equipped trucks this connector has a factory jumper installed like in the picture. On manual trucks there should be a harness plugged in that goes to your switch.
Nice looking truck BTW.
I don't have any pictures of that particular harness, but look under the hood on the driver's side splash pan. There will be a small "L" shaped connector with two wires going to it. This is where the back up light harness should plug into the main harness. On automatic equipped trucks this connector has a factory jumper installed like in the picture. On manual trucks there should be a harness plugged in that goes to your switch.
Nice looking truck BTW.
Thanks for the responses. Mike - I took a picture of this connector with a jumper on mine? Is this confirmed to be the right harness? Kind of strange there would be a jumper in there right? Thanks!
Is this confirmed to be the right harness? Kind of strange there would be a jumper in there right? Thanks!
Yeah, that's the right connector. You're right, it's kinda strange that the factory jumper would be there with a manual transmission.
Do you know if this is the original harness for the truck?
With that jumper there, your backup lights should be on....unless...Check the main harness under the dash. Look in the area of the steering column for a flat four terminal connector. It looks like a trailer light plug. This was the connector for the factory NSS for an automatic. Yours should have a dummy plug plugged into it to bypass the neutral start. If it doesn't have the dummy plug, that would explain why your backup lights aren't on now.
Thanks Dummy. And thanks Mike. I'll have to do a little more digging. And grab some more pictures. So probably stay tuned! lol
To answer your questions. The reverse lights are not on. And I have not seen a 4 terminal connector behind the dash or near the steering column. But will double check.
Here's a picture of the plug under the dash. In an automatic truck it plugs into the column mounted neutral start switch. When the truck is equipped with a manual transmission, the plug is still there but it has a dummy bypass plugged into it to bypass the neutral start function and so the back-up lights work.
Here's a picture of the plug under the dash. In an automatic truck it plugs into the column mounted neutral start switch. When the truck is equipped with a manual transmission, the plug is still there but it has a dummy bypass plugged into it to bypass the neutral start function and so the back-up lights work.
Thanks I just found it. Picture below plus another of the jumper on the harness. Ordered a harness. Coming tomorrow. Gonna plug it in and see what happens.
I'm going to assume that the wires in the right side of the picture have been cut, you can't tell from the picture.
Once you get the new harness, you'll need to make sure the two pairs of wires are connected.
In automatic trucks, the NSS is a compound switch, it's both the neutral start switch and the back-up light switch. Right now you should have one pair of wire connected (the neutral start switch) and one pair not connected (the back-up lights). You'll need to connect the back-up light wiring to make them work.
Thanks for the update.
