As most of you know my 1970 F350 has had some electrical gremlins or at least a poor rewire job by the PO.

I was not getting brake lights consistently on both tail lights. I thought the easiest way to fix it would be to hook up separate brake lights and run a new wire.

I found a set of taillights from that vintage, painted the bodies and put them on next to the other tailights. The plan is to use the existing lights for tail and turns and the new lights solely for brake lights. I am using the new lights as backup lights also since the PO had a huge ugly headlight that is used when a pickup has a snow plow attached. The backup lights do work...

I ran a wire from the new taillights up under the truck. I cut the brake light wire (red/black) where it came out of the firewall. The brake lights were on full time even without the brake pedal depressed. I could not figure it out so I reattached the wire I cut...

I thought this would be a simple fix. On my '54 you run a wire from the brake switch to the brake lights... nice and easy. I know the brake lights are incorporated with the turn signals but I thought since I am using separate lights for the brake lights I could by-pass that. I guess not. Did I cut the hot wire that goes to the brake switch? Tomorrow I will cut the other wire unless someone here can help me other wise.

thanks!

 

bump to the top... still looking for answers and help

perhaps the PO switched the power and brake light wires (red/black and red) when he put a new steering column in...

snowing here today so I won't get to it today...

 

You can't use one for brakes the other for turn as they are wired to work together. You would need to wire a direct wire from the brake light switch to activate your new brake lights. Sounds like you got a real issue with the wiring. Just have to pick through til you find the right wire. Maybe start right at the brake pedal and go back. One side should be 12v source, the other side would work for you.

 

Here's what i did. Run a wire from power (Ran my from bat) with inline fuse to brake light switch using female connector. Run another wire with a female connector to other side of brake switch and down to a back light. Connect another wire from that light to the other light. Get two small turn signal sockets and bulbs make sure you have a few inches of wire on each. Run wires to the inside of light hook power to one side of socket and ground the other wire. Be sure to keep light away from plastic lense cover. Not as hard as it sounds.

Temp fix till you get it sorted out.

 

Same Taillights: 1967/79 F100/750 Flat & Stake Beds & F100/350 Flareside Pickups & 1967/79 F100/750 Cab & Chassis.

 

Number Dummy, I am looking for these #s.
f3ly 6p068 a cover qty 1
f3ly 6po68 b cover qty 1. I already checked with Green Sales. n.a. Thanks.
Kenny

 

No FoMoCo Dealer or obsolete parts vendor has any.

 

Yes, that is what I did. Ran a 14 gauge wire from the firewall under the truck to the new brake lights. So am I right to think that I spliced into the power wire and not the wire from the switch... It snowed today and is cold, supposed to have a windchill of 5degrees tomorrow morning.

I do have a real issue with my wiring. There must be a bare wire somewhere grounding the circuit. Sometimes when I put on the brakes the clearance lights come on... so that is one reason why I tried t fix it like I did,new wire, new brake lights...

The PO used orange extension cord, Romex house wire for wires and used wire nuts instead of crimping the wires together and using shrink tubing...

I'll get it fixed a little at a time, but brake lights are first on the list of course.

Thanks for all your help...

 

Thanks Bill. The lights I got were from the 80-86 series, I think. They are rectangular similar to what was on my 70 originally but the backup lens is larger, more rectangular than the 67-79 series lights.

I will post pictures later.

 

Unfortunately I sold the complete wiring harness from my '67 F100 a few years back when I scrapped the truck. It was PERFECT, no cuts, no add ons, nuthin'. There is NOTHING worse then hacked up harnesses. Lucky all my vehicles are mostly unmolested and work well.

 

Good news! I got my new brake lights to work!

I first connected the new wire I ran to the red/black wire coming from the brake switch... didn't work, brakes were on full time so I thought that must be the hot wire. So yesterday I cut the other wire and connected that.... didn't work! I was miffed!

This morning I was working on the left tail light and I saw my new wire coming from the front was not connected to the new brake light wire... duh, I had disconnected it and had forgot.

So when my son came home from his college class, we ran out, I went under the hood connected the wires I tried yesterday, he hit the brakes and I got bright brake lights on my new (junkyard fixer-uppers) lights! Now it is safe to drive. I only have the left tail light that does not come on for the tail lamps.

I will try to post pics tomorrow.

thanks for your help everyone.

 

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