Backup Lights not working 1968 Ford F100 Ranger

[west_seth]

Truck:
1968 Ford Ranger F100 360 engine, Automatic transmission, no power steering or brakes.

What I have done:
new bulbs
fues are okay
installed a new neutral safety switch (this is where my question lies)
backup lights used to work I don't know when they stopped working or why
All other lights are working fine

===
I found the neutral safety switch on the inside of cab under the dash on the steering column. I thought this controlled the backup lights. Replaced the switch. Backup lights still don't work.

Is this neutral safety switch indeed the controlling device for the backup lights? or am I missing something? If it is I don't understand how it would control the backup lights.

This switch has two black wires and two red wires with a black stripe. I can see how when you shift it into park the switch makes contact (or bridges the contacts) so the truck will start in either PARK or NEUTRAL. I just don't get it how it would control the backup lights.


Any ideas? Am I missing the real location of the backup switch? It is my understanding manual transmissions ONLY have the switches either on the steering column under the hood or on the manual transmission.

I am stumped.

[rjewkes]

ok i beleive either manual steering or power steering they have the switch on or in the transmission. And it could just be your wires under the truck. or a loss of ground.

[bluef250]

Follow 140/140a from rear light through the switch

http://www.fordification.com/images/sch ... ghts02.jpg

I think, not certain, the manual and auto transmission both have back up light switch on the tranny. Let us know what you find out. good luck.

At the rear check ground first, recheck that bulbs are good (some bulbs are bad), and work toward the front of the truck.

[dcbullet]

Is this neutral safety switch indeed the controlling device for the backup lights? or am I missing something? If it is I don't understand how it would control the backup lights.

Yes, it also controls your backup lights. As far as how it works, when you slide the lever into just the right spot, it must make contact and complete the circuit.

bluef250 attached the 67 wireing diagram, but the 1968 is a little different.

It is here:

http://www.fordification.com/forum/download.php?id=610

You will note that the connector labeled U, next to the dimmer, is the 4 wire neutral safety/backup switch wiring.

If I were you, I would fiddle around with the lever manually, and have a test light on the backup light wiring to see if it gets power. That's your first step. If it is indeed working, then you just need to make sure the switch is properly set on your column.

Good luck.

[west_seth]

Thanks a million.

One more question.

On the wiring diagram:

Next to the wiring legend there is reference to a backup light switch. I see the one you mentioned labeled "U". But can not figure out what the other one is?

[dcbullet]

Next to the wiring legend there is reference to a backup light switch. I see the one you mentioned labeled "U". But can not figure out what the other one is?

I believe that is for the manual transmission which I think (not 100% sure) is on the transmission itself. But U is definately the nuetral safety/backup switch for an automatic. I have a 68 automatic as well and I had to undo significant buggary from the prior owner. I got to know my wiring really well.

[west_seth]

Thanks a million for your help on the backup light saga.

I now have enough information to trace the problem and/or find the solution. Someone told me that in theory these old trucks are pretty simple. Of course tracing wires in a cramped space is not easy.

I have a combo. OHM meter and I can trace voltages pretty easily. If push comes to shove I can always run a hot wire from the fuse panel to the Neutral safety switch and if need be run a wire from the NSS to the backup lights. I now see how the NSS switch works and I was wrong in the my theory that part of the contact was for starting in park.

I have had my truck since 1973 and am the second owner. My goal is to restore it to some condition. Maybe not factory not enough money in my pocket.

Thanks again.

[flyboy2610]

Electrical problems can be a source of great frustration. You'll get it figured out.
I like that word: buggary.