QuestionThe brake lights quit working, I've replaced the bulbs, the tailights work and the turn signals work. I replaced the switch on the master cylinder. There is no fuse block on this car that i can find. Any idea what to check next? I have had problems in the past with different new parts being bad from the parts store. It was a borg warner switch.
AnswerThere is a fuse in the brake light system, but before we go off looking for that again, take a test light or a voltmeter and verify that you have 12 volts on either of the terminals of the brake light switch. If you don't, your problem probably is a fuse, but if you do, the problem is elsewhere.
To troubleshoot this further, assuming that there is 12 volts on one of the terminals (it doesn't matter which one), take the two wires that go to the brakelight switch and temporarily connect them together with a short clip lead. This should bring your brake lights on. If they are still not lit, try wiggling the turn signal switch lever while someone else watches the brake lights - a common problem is an intermittent connection inside the turn signal switch, which is in series with the wires to the two brake light filaments. In other words, if you can make one or the other of the brake lights come on by wiggling the turn signal switch, your problem lies in that switch.
Back to the beginning now: If there was NOT 12 volts on either terminal of the brake light switch, make sure that your key is on, and check again (some Fords require the key to be on to activate the brake light system). If there is still no 12 volt there, it's time to go hunting that fuse.
To track down any electrical problem on a car, you really need to have the wiring diagram, which is included in the factory shop manual. If you are going to be maintaining this car, and you don't have the manual, it's time to get one!
Any of the major literature dealers can sell you one, or you can watch on eBay for one. If you want to get on it right away, contact Ed Faxon at www.faxonautolit.com - he will have one and it will help you fix anything on the car.
If you have the owner's manual, that will also tell you where the fuses are for the various functions on the car. Ed will also sell you one of those, if you wish.
I don't have all the manauls for all the cars in the world, so I'll have to rely on memory here, but as I recall, the brake light fuse also supplies power to the dash illumination on this car, so check to see if your dials all light up when the headlights or parking lights are on - if they do, the fuse is probably OK. If they don't, for sure you have a bad fuse. If you follow the two wires that go to the brake light switch, you can find the fuse as follows:
one of the wires goes into the steering column and up to the turn signal switch. The other wire is the one you want - it goes to the fuse, wherever it is!
This is getting too long here - take what I"ve said so far and see if that leads you to the problem - if not, post a follow-up question to me and I'll try harder.
Dick
