Weird dash wiring gremlins

03wr250f

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I recently bought a 87 f250
6.9 4 speed extended cab long bed 4x4 n/a
Lots of hacked up wiring and things hooked in to weird places
When I got it the brake controller was hooked into the power wire of the brake light switch, backfeeding and causing brake lights to be on any time the battery was hooked up.
I have since removed the brake controller. As soon as I Undid the wiring from the brake controller the rear antilock light came on.
About a week later when I went to work on it again and hooked the batteries up the coolant temp gauge in dash pegged out and is now tripping the engine warning light. I also have been having issues with the tank selector switch in the dash.
And I have issues with the marker lights. When you pull the headlight switch out the turn signal indicators in the dash light up. (Already replaced the burned up connector, and switch. Did it before replacement as well.)
Also have disconnect the rear trailer plug wiring due to scotch locks and corrosion. I will repair it shortly.

All that to say, does anyone know of a common dash ground or similar that I'd known to fail. I am almost wondering if there isn't a common wire that could be contributing to the symptoms. I remember hearing the brick dash grounds weren't that great.

If not I will work my way through troubleshooting, because maybe, the vss died, spontaneously the coolant temp sensor failed, and the tank selector valve or senders died too.

Thanks
 

Nero

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There's a ground stud on the dash, just under where the plastic stops, just to the left of the column. It's hard to miss. Can't tell you how many trucks that's all corroded up and causes weird issues.
 

03wr250f

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I'll check them both out, thanks guys.
Recently got done doing, front brakes, u joints in knuckles, front drive line, return lines, glow plug ends, blower motor, etc
Tomorrow it's time for wiring issues and other loose ends
 

03wr250f

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I'm sure everyone is on the edge of their seats waiting for a resolution.
It was a bad marker light socket.
The socket internally had rusted the ground. It was then trying to ground through the turn signal system thus lighting the dash indicators.
What made me look there was one front marker light was not working
Dash ground was good, cleaned anyway
No ground in kick panel
 

DaveBen

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I had a marker bulb go out. It shirted = to - when it blew. It took several days for me to find the short. It blew the running light fuse every time I turned on the head lights. I had NEVER seen s bulb go out with a short to ground.
 

Nero

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It's crazy what one off issues can cause. On my dad's car, one of the headlight bulbs I put in was manufactured incorrectly, and both high beam and low beam circuits were touching. So turn on the head lights? High beam indicator turns on, but just one headlight is low beam and high beam on. Would last a day then pop the fuse. Glad you found the source of this issue.
 

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