Need help with Turn Signal Switch - Colors wrong - Blowing Fuse

[dwildey]

Hello everyone -

I have a 1971 F250 RANGER XLT in the 20,000 serial range. My turn signal switch has been a nightmare. Signals stopped working and old one was bad. I bought replacement but colors don't match. They gave me a cross reference chart for new colors for pinout, but I am blowing fuses with Brake and turn signals don't work. I know it's in the switch, but can't figure out what goes where. I have triple checked and everything is correct according to their chart. I even took to mechanic and electrical place and neither one could figure it out. I check all wires in column and there are no shorts. (This is all new to plug, not repair kit). I've downloaded the master electrical chart and all the colors and pinout is correct from dash to where it plugs into turn signal switch. If I unplug it, everything is fine so I know it's in ping order / colors of turn signal switch turning going into factory plug. (I even replaced all bubs which work.)

Does anyone one have details or diagram for what each wire would do on the turn signal switch? I tried with my multi-meter and can't figure it out. If I could, I could make sure they are correct to factory plug.

Any help or pointers are appreciated. Thanks in Advance!

Here are pics of plug and column water -
https://drive.google.com/drive/folders/ ... sp=sharing

[MadMike]

How did the old switch go bad? Mechanically or electrically?
If the switch failed electrically, verify that the lamp wiring harness throughout he truck is not damaged. Recheck all lamps are correct and the correct sized fuse is used. Verify the switch is correct for your application.

If there have been added on accessories, verify they are correctly wired.
Any changes/maintenance done to the truck before the original switch failed? Go back and recheck that work.
Check the wiring and blinker(s) for the Hazards as well as the brake light switch and horn.

When does the fuse blow?
When the power is restored?
When the parking lights are turned on?
When the turn signal is activated?

[dwildey]

Turn signal switch was mechanically bad. Fuse blows when brake is applied. Turn signal relay clicks once then stays that way until key is off.
I have isolated it down to dash / plug. Have disconnected harness in front of firewall and the one under the bed by 2nd gas tank on frame. Fuse still blows when either or both disconnected. Fuse also only blows when turn signal switch is plugged in. I am guessing the wiring is wrong even though it is "right" according to legend.

I can't figure out how the wiring works on the turn signal switch or what combination goes where. If I knew that, I could put them in the right place in the plug to mate to factory wiring which is correct on that plug.

[sargentrs]

The '72 Master Wiring Diagram is about as good as it gets for the fine detail of the TSS. http://www.fordification.com/tech/wiring_1972master.htm Page 6, section D-59. I believe '71 is virtually identical.

[Ranchero50]

Yep, need a good schematic and even better volt / ohm meter to troubleshoot it. Posting some pics of the switches might help as well. No easy answer but it'll be something dumb causing the problem.

[basketcase0302]

"sargentrs"]The '72 Master Wiring Diagram is about as good as it gets for the fine detail of the TSS. http://www.fordification.com/tech/wiring_1972master.htm Page 6, section D-59. I believe '71 is virtually identical.

Actually I found that to be just the opposite on my 1971 F-350 Randy. You have to keep in mind the 1971 year model had a cut off in sequential serial numbers that make more than one aspect on the trucks different including the wiring.
Best advice in the world would be for you to invest into this simple color coded laminated wiring diagram. You take this and roll it up and store it in the glove box for when the truck breaks down and your stuck on the side of the road trying to find your resistance wiring or headlight wiring. It'll be the best $18.00 spend on the truck! I found it got me into the ball park, (I even found discrepancies in it-but not enough to complain about):

https://www.ebay.com/itm/1971-71-Ford-F ... S-&vxp=mtr

[sargentrs]

Thanks for the correction, Jeff! I'll put that in my "things to remember" file. I hate giving someone bad information. I've always wanted one of those diagrams you mentioned. Wish we had the '71 schematics here.

[71Fe2O3]

Thanks for that.
I have a 71, and, though my problems have been small compared to those encountered by basketcase0302, I occasionally run into a difference when using the wiring schematics found here.
For now I am hesitant to spend $18 plus shipping for the diagram, but lamination and color-coding are appealing features.

[basketcase0302]

Randy any information given here as far as I'm concerned is at least trying to help folks-which counts. My Ford wiring skills were honed, (and username created) by a Duraspark II ignition system in my old style 76' Bronco in the early 80's. It would blow an electronic ignition box every three months without fail after I bought it off a car lot in Florida, (PO gave up on it). Months later I finally pulled the entire wiring harness out, (no wiring diagram available for it) but HVAC for trade I decided that I'd had enough at $40-$60 a box! I found two wires that had been pierced previously by a screw for an under dash CB or stereo that would not ohm out as bad-yet would short when bumped together. The rest was a 20+ year ownership of a bullet proof Ford.

That laminated wiring diagram got me out of a bind more than once-I let it go with my old truck to help the new owner Todd.
This one is also a good one to print and keep in the truck guys as it too gets you close enough to help-like Randy did.

[dwildey]

Thanks guys. I just ordered a new turn signal switch which uses all the factory colors so it should be 1 to 1. I will let you know if that works better than the one with a legend.

And there are two different configs on the 1971 for turn signal switch and wiring. Mine is the earlier version. Apparently, late 71's in the 30,000 serials are more like the 72.

[basketcase0302]

"dwildey"]Thanks guys. I just ordered a new turn signal switch which uses all the factory colors so it should be 1 to 1. I will let you know if that works better than the one with a legend.
And there are two different configs on the 1971 for turn signal switch and wiring. Mine is the earlier version. Apparently, late 71's in the 30,000 serials are more like the 72.