1971 F250 with brake light and turn signal problems

F6 lathead

Well-known member
Hello, I have a 1971 Crew Cab 4x4 5.9 Cummins that I am having brake light and turn signal problems with. The turn signal switch in the column is toast and only works when you hold it in position, but that does not always work either. Sometimes I have brakes lights on both sides sometimes its only the left side but it keeps changing. I am going to start by replacing the turn signal switch first, from what I have read on this forum it appears that everything goes through there or gets mixed up there if its not operating correctly. I have done some research on turn signal switches on line and have seen some that we're for non 4x4 trucks is there a difference from 2 wheel drive? Also I wanted to put in a ground strap from the motor to the firewall and then from the body to the frame any suggestions on where to attach them? I also read that someone had put in a ground from the dash to the body where was the ground attached at each end of this ground? Thank you for your help.
F6 lathead
 

Lazy JW

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On my White Ox I connected a wire right to the bottom of the metal part of the dash near the ash tray, and ran that wire up to the engine and sandwiched the connector on top of the ground wire from the battery. That's about as "grounded" as you can get; it certainly solved my flakey instrument problems.
 

Lazy JW

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Also, do replace the turn signal switch. My White Ox needs one too; it works, but will not self-cancel anymore.
 

F6 lathead

Well-known member
i replaced the turn signal switch, and everything worked fine, and then it didn't. I am not sure what the trouble is but I am going to start testing wires from about mid way back to the rear and trouble shoot from there I detest vehicle wiring!! issues but thats the way it is when you own stuff thats almost 50 years old! I am looking for a place that sells just the rear/taillight section of a good quality wiring harness do you know of any. I have seen where you can buy just sections instead of the whole harness years ago but can't find them now. I would be interested in buying the black male/female wiring plugs as well and making my own harness but I don't know where to buy the rubber plugs from any suggestions? Thanks
 

Lazy JW

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I'm afraid I won't be of much help as I build my own wiring harnesses and I never use any factory type components.
 

bubba22349

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Check with NAPA they used to have those wire plug ends in their Echlin line. Good luck (y) :nod:
 
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