Recently acquired a great 1988 F250 (Z code manual transmission) 4x4 with a 460. Love the truck but have been chasing down years of electrical tinkering by previous owners. I noticed weeks ago that my reverse lights do not come on when I shift into reverse and after lots of troubleshooting, I have reached a dead end.

I traced the wires all the way to the bulbs and replaced the bulbs with the specified type. I found the switch atop the manual transmission and jumpered the two wires in that harness. Reverse lights then came on when I turned on the key. Yeah! Okay, so I ordered the Motorcraft replacement switch (even though I had continuity in the old one when I depressed the ball end). Just installed the Motorcraft switch and tested again...no reverse lights. Ugh.

Looking for suggestions for what to try next and am worried that all this means the dohicky inside the trans that presses the switch is buggered somehow.

Thoughts? And thanks in advance.

 

my reverse lights on my 88 were hit and miss from new. i simply wired in a toggle switch and turned them on when i needed them. and since the lights in the tail light are all but useless i mounted a good set of flood lights under the rear bumper, and another set on the headache rack.

 

I think the previous owner did that too. There were two crusty old lights under the bumper with wires running back to who-knows-where. I will eventually add a reverse camera to this rig, but if I can't even figure this little problem out, I'm not sure how successful I'll be at something more complex. I'm really just trying to get this truck back to stock operation.

Do you know if anyone has tried running a reverse light switch into the trans that has a bit longer of a threaded shaft, extending the ball farther into the trans? Might be playing with fire, but I'd really like to lick this.

Appreciate the reply!

 

When I did the M5OD to ZF5 swap I did not have reverse lights. They worked before the swap so I jumpered the connector and the lights came on. I was going to replace the switch since I didn’t know if it worked before. I don’t know why but fiddling around with the connector on the switch fixed it for me. It must not have been making good contact.

 

Interesting. I'll fiddle with it a bit and see what happens. I have to do everything by feel since the switch is on the top of the trans and inset a bit. The "ears" of the connector were no longer elastic; I had to push on them to get them to engage the switch and stay. Since I probably cannot find this type of connector anywhere, I'll have to get creative. Maybe with a zip tie and infinite patience?

I suppose I could test this setup with two alligator clip test leads, if I can find a way to blindly connect them at the switch side.

The switch isn't polarized, is it? Just the two contacts and I did not see any limiting lugs in the connector.

 

This says it is for a 4 speed but if I remember correctly from when I was looking, it is the same for the 5 speeds.



No. The connector does not have to go a certain way. It plugs in either way.

 

Oh man! If I can snag one of those it will answer that question for sure! Thanks so much for that resource.

 

i replaced the 5 speed with an automatic trans in 2000 when the transfer case self destructed. while pulling everything apart to inspect the clutch and trans because the 5 speed was tired after 350,000 miles, i also had the dual mass flywheel fall out in 4 pieces. since i already had the C6 trans, i just stuffed the automatic in and left the manual reverse lights.

 

This morning, I disconnected the connector and noticed that, in addition to the loose connector arms, one of the female receptacles appeared to be oversized by a bit (from being worked on over time I think). I inserted two pins into the connector female end, then ran two test leads up to the switch. When I shifted into reverse, the lights came on. So, I think the connector may be the culprit. I've ordered it from Rock Auto. And I'll report back here what the results are.

Thanks for the suggestion.

 

You can just take some copper wire pieces from some wire stripping repairs etc. and cram them into the female end then install the connector
That has been happening to those connectors for years and years
Great news, you found another connector

 

maniacmechanic007 for the win!! Your solution was the only one that worked after I did several other 'more elegant' solutions. What a frustrating ride!

I bought two connectors; one from the jungle website that got here fast and one from Rockauto that got here as fast as anything from Rockauto gets here (yawn). Both connectors looked exactly the same, and both had hard plastic center parts rather than the soft rubber OEM one.


OEM Left


That hard plastic, and the fact that the female ends were about 1.5mm wider than the OEM one, didn't seem very important, but it made all the difference in the world. The hard plastic just would not slip into the reverse switch without considerable effort, and that effort always dislodged the female connector parts, resulting in no reverse light connection. The OEM part had female connectors that had spread a bit and were also pushed out by the male pins in the switch because of age.

So I took maniacmechanic007's advice and 'alternatively engineered' a solution; I used two of those heat-shrink butt connectors that have solder in the middle, but cut one end off so the solder was now at the end of the connector. I put one of these on each of the pins of the switch, heated them up, and voila! Two soldered wires. Not trusting that they wouldn't work loose, I then filled the void in the switch body (that the connector I purchased would normally occupy) with hot melt glue. Wrapped that with a little gorilla tape and had me one UGLY but functional switch pigtail. Bench tested for continuity and then installed it.




For the first time, I now have a legal set of reverse lights on my truck.


Thanks to all for the suggestions. And a special thanks to maniacmechanic007!

Jim