I need the diagrams to figure out no brake lights. All other lights and flashers work, so does the brake light switch on the pedal. I bought a Chiltons repair manual for 65-86 and it gives me nothing. Does anyone have them available?

 

You probably can buy them at the store on this site. If you have a testlight or voltmeter, you should be able to figure it out without a diagram.

Put the testlight or voltmeter positive lead on one side of the brake switch. Put the negative lead on a good ground. You should read 12 volts. If not, go to the other side of the brake switch. You should read 12 volts. One side of this switch has got to have 12 volts on it, and that comes from the fuse box.

Now read the opposite side of the brake switch with the pedal pushed. You should have 12 volts with the pedal pushed, and no volts when you let up on the pedal.

If all that works, you then need to go to the steering column. Make note of the color wire that had on-off 12 volts on the brake switch. You will find this same wire going up the steering column. If you test it going into the turnsignal switch, you should get the same on-off 12volts when the pedal is pushed that you got before.

If you have the on-off 12 volts going into the turnsignal switch, and your rear turnsignals do work, then your turnsignal switch is bad.

The rear turnsignals use the same wiring and bulbs as the brake lights. So if they work, that means the wiring and the bulbs are good from the rear all the way to the turnsignal switch.

 

Thanks so much, that even makes sense to me. I'll check that out.

 

you can find wiring diagrams (for your particular vehicle) plus much more at the AutoZone website. very helpful and handy.

 

Using the CD from motorhaven.com I rewired the whole light system on my 1971 F-100 including under the dash and eliminated the column switch. The only thing I do not have is the self canceling cam. I put everything (stop, parking, turn signals) on its own 30 amp relay so my trailer stuff will not overload the headlamp relay.

The easiest way to track down problems is to unplug the harness under the hood, stick a test light clip into one of the four holes and figure out if you are actually getting power out of the cab side. If you are, then the easiest thing is to go buy a 4 wire trailer harness for $15 at Advance Auto Parts and run it all the way back to the rear lamps and splice in new bulb connectors.

If you plan on trailer towing, then for each wire (four) run an extra wire from the butt connector to a Hoppy converter and that to a 7 pin/4 pin connector from Northern Tools so you can use both 7 pin round and 4 pin flat connectors on trailers.

You can do the whole thing for under $80 including the connectors and adapters for trailers. Or $30 if you skip the trailering stuff and relays.

 

I am curious how you wired the combo brake/turn function? Did you wire seperate turn lights in the rear? I know of two other ways to do it, without using the factory turnsignal switch, but I was wondering how you did it.

 

I am also interested in finding out how you did it--i have a 1973 F-100 2wd/360....I am currently having problems wiring turn signals and brake lights....i had a setup that worked for a while then quit....now the battery is being drained...got an open circuit(burning switches 2)....

any help would be appreciated


Jeff