Help - 1990 F150 brake lights

[montesa]

I noticed that when I move the turn signal handle the one or the other brake light would turn on. If I find the perfect spot moving the turn signal/tilt handle both brake lights will come on. I think it’s in the turn signal canceling cam. It has two metal wires that make contact at different times. I don’t understand how it works. I bent the wires around and there was some improvement in the brake lights both coming on but it still has to be in the right spot or they both won’t come on. Anyone familiar with the system? There are four contacts the wires make contact with.

This thing is driving me crazy. Pic is of a new canceling cam so you can see the metal wires on the back that contact the raised points on the turn signal switch body.

 

[Snattlerake]

Is there still a brake light switch on the brake pedal under the dash? That switch used to be adjustable. Follow those wires up to the steering column mechanism and use a meter to check grounds and voltage.

Turn signal schematic below

https://www.ford-trucks.com/forums/1318494-schematic-for-1990-f-150-a.html

My guess would be the multifunction switch

 

[montesa]

Is there still a brake light switch on the brake pedal under the dash? That switch used to be adjustable. Follow those wires up to the steering column mechanism and use a meter to check grounds and voltage.

Turn signal schematic below

https://www.ford-trucks.com/forums/1318494-schematic-for-1990-f-150-a.htmlView attachment 329186

My guess would be the multifunction switch

Yes. The brake light switch is working correctly. It doesn’t have the multifunction switch. Too old.

I think I know what it is. The canceling cam solid wires need to be bent out not sideways to make better contact with the points/nubs. Found this on a forum.

 

[Catt57]

Best way to fix it? Replace the truck with a Chevy.

Sorry, I just had to.....

 

[montesa]

Best way to fix it? Replace the truck with a Chevy.

Sorry, I just had to.....

I’m actually considering it. Get a few more things fixed and this one should sell for enough to get half a Chevy. I wanted a Chevy but the short wides aren’t cheap. This is a short wide ford and I love the look also but prefer the Chevy.

 

[montesa]

Everything was working, went for a drive and the turn signals quit working. The cancel cam is a universal fit so it’s a pretty poor fit. It’s a terrible design as it is. Feels like breaking a raw chicken bone when engaging the turn signals. Can’t expect much for 9 dollars delivered. Going to see if I can find the actual ford part. At least I can drive it with brake lights now.

 

[montesa]

In this pic you can see the solid wires and the 4 points it connects too. You can see the poor connection burned a bit of the plastic. It’s just crap.

 

[Snattlerake]

It looks like you found a problem. A little bendy bend and a little sandpaper will fix that. I'd put a small drop of silicone under that wire to keep it shimmed up. Wait until it dries before use.

 

[montesa]

It looks like you found a problem. A little bendy bend and a little sandpaper will fix that. I'd put a small drop of silicone under that wire to keep it shimmed up. Wait until it dries before use.

That’s a great idea. Otherwise the problem will come back quickly I bet. It’s all back together now. Can’t believe it took that long. Just when I think I’m smart a little wire gets the better of me.

I can’t believe they run the brake lights through that cancel cam. I wonder if I can change the wiring to bypass that and have the brake lights come on even if that cancel cam isn’t there.

 

[Bravo1413]

Replace the turn signal harness. They get worn out.