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70 Turn Signal Wiring Problem

494 Views 3 Replies 4 Participants Last post by  bodyputty
When I pull the light switch on the left turn signal light comes on in the dash. If I throw the turn signal switch on for a left turn it operates normally and after the turn the light stays on again. I have tried to trace it out but no luck. Any ideas? I see the light yellow wire from the dash going into the wire loom but am unable to trace it out. Is there a relay under the dash that might be bad? I here a loud click when I turn on the lights.
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most of the wiring problems can be traced to bad or deteriorated grounds. I know on the front 69/70 harness, there are at least two ground wires that attach to the front radiator support. Troubleshoot the ENTIRE harness and make sure you are getting good ground.....

more than likely your front turn signal housing isn't getting a good ground....I hate the fact in 70 ford got cheap and apparently eliminated the ground wire coming out of the bulb receptacle!!!
The housing of the front facing turn signal light that attaches to the front bumper is the ground for the circuit. If this housing is loose,or the screws that mount it are corroded the dash indicator stays lit...You may also have a failed head light on that side. The light may not be out in low beam,however, the high beam filament may be open. I recall that in a certain head lamp switch position, the high beam filament is the circuits ground. Try the housing ground first. I'd bet the ranch that this will be the trouble.
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