Hi all,

I would try to find a relevant post, however there appears to be no search function available on this board. Unbelievable.

I need help with my F250 truck brakes (6.9L diesel automatic XLT 2 wheel drive). There is good power to the "stoplight switch" on the brake pedal, and the stoplight switch is working. The bulbs appear to be totally great, no burns noticeable. My turn signals and rear running lights are working fine.

1. Is there an inline fuse between the stoplight switch and the brake lights in the rear?
2. Is there a relay after the stoplight switch that I need to look at?
3. Where does the wiring go after the stoplight switch - I'd like to trace from there rather than from the rear.

Thanks!

 

I forgot one clue: while the rear turn signals are working, the hazard lights only flash in the front.

 

Sounds like the turn signal switch is failing. There is a fuse for brake/turn signal lights. Look at your fuse block it should be labeled.

 

Thanks for the reply. All fuses look good. I recently replaced the turn signal fuse (is this the same one as the brake lights?).

If the turn signal switch is failing, how do I fix that? Do I buy a new switch, and if so, how much should I pay? Is it easy to replace? Where do I find it?

thanks

 

New complete switched run around $50-75. Your local parts house should carry them. To replace them start by disconnection the battery grounds. Then you need to remove the steering wheel to gain access. I have not done one that new. Maybe another users can post the instructions from the shop manual.

 

SPEEDCAT,

i find this very starnge. i have an 86 f250 that had the 6.9 in it. when i was putting my 400 in the truck and after i got it running i did not have break lights. i checked all fuses and replaced the brake switch and still no fix. i repaced the trun single and haz relays and still no fix. i have not found the right way to fix this problem but what i did was run a pos wire from the fuse box to one wire on the switch which fixed the proble. i taped in on the green wire with red strip.
let me know what you come up with

 

oh to change the trun single switch is not too hard at all. remove the cover from the streeing wheel andremove the bolt in the middle, get a streeing wheel puller and remove the streeing wheel. after you get that off you should have like 2 or 3 screw remove them and remove the turn single stick but truning it. then you will have to remove the plastic cover from around the steering shaft and un plug the wires. now the switch should be ready t be replace.

 

clunker86, it sounds like you may have lost a fusable link on you 86. On some of the older F100 they a single fuse that did the stop and tale lights.

 

it wouldnt surprised. i took a truck that had a 6.9 in it and put a 400 in there. i dont know if im going to mess with it any more or at least at this time. i done took the whol dash out and replaced it and cleaned all the wires back up, but i will have to get back in there one day to fix my trap door on the ducking

 

Thanks everyone. I think you may be on to something, Clunker86. On one of the wires off the "stoplight switch", there was a lot of electrical tape, as if there was a short there previously, or as if someone had already tapped in like you mention. I'll open that up & see if there's a short there, or try tapping in & see if it helps.

Also - does anyone have a diagram of the fusebox for this 86 F250? my fusebox cover has fallen off and lost itself somewhere, and I have no idea which fuses are for what systems. I'll need to know which one is for the brakes if I'm going to tap into it as noted above.

Thanks!

 

This isn't intended to be rude by any means, just as a point in the right direction for future inquiries.

http://i10.photobucket.com/albums/a142/Grey_Wolverine/search.jpg

There is indeed a search function on this board, but is easily overlooked at times due to it's location. I myself had to look hard for it the first time.

 

Yeah - the problem was, when you first register on the board, it indicates you are logged in and you can proceed to the forums. But you're not really logged in, hence you do not see the Search link.

 

1 more clue here (does this point more to the turn signal switch failing?):

The turn signal lights work fine in the front. In the rear, the right turn signal works fine, but the left turn signal actually makes both rear turn signals blink. I just noticed this. Weird.

 

OK - I just want the brake lights to work.

Rather than buy a new turn signal switch, try to open up the column and pull off the steering wheel (been there on an old Lincoln... no fun), I'd rather bypass the turn signal switch on the column, and just run straight from there to the brake lights. Lower terminal off stoplight switch direct to green (left rear brake light) and orange (right rear brake light).

Yes, when I have the brakes on, and turn signals on, one or the other will win... hopefully I don't blow anything up. Feel free to criticize this plan at will.

 

There is a way to rig it, and make it work correctly. Your plan is not going to work. I did this to a 53 f100 I added turnsignals to, and it worked great.

You do need a turnsignal switch. A toggle will work. It needs to be single pole, double throw. It will have three terminals on it. The center will be a common.

Then go to the store and buy a trailer adapter. This is a little square box with 5 or 6 wires coming out of it. It costs about $12.00. It's made to adapt European type cars with yellow turnsignals in the rear, to work with american style combined lamps on trailers. So this is exactly what you are going to be doing, combining the seperate signal from the brake switch and your new toggle turnsignal switch, into the one original red taillight. Here's a diagram.