Taillight issue

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shortbedCUSTOM
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Taillight issue

Post by shortbedCUSTOM »

Greetings all,

I'm in the process of sorting out a taillight issue on my '68 Ranger. Due to the lack of availability of a taillight harness for these trucks from the aftermarket, I decided to print out my specific wiring diagram and repair a section of it. I followed the diagram to the T and now I'm having an issue. The section I repaired is at the driver's side rear corner. As most of you know, this is where the long harness that runs from the front to the rear corner connects to the taillight/license plate and left taillight bucket harness. So there's three connectors in this corner. One for the taillight bucket and two that make up the rest of the taillight connections. Almost every wire that led into the factory connectors was barely hanging on with a single strand of wire and there were cracks and bare wire sections throughout. I cut a good section fore and aft of the connectors and replaced with new wire and soldered it back up according to the wiring diagram omitting the connectors.

Now for the issue(s).

1. The passenger side park/running light is considerably dimmer than the driver's side.

2. When applying the breaks with no other lights on, passenger side brake light considerably dimmer.

3. When applying the breaks with other lights on, the passenger side break light and running light go completely off.

I noticed while rewiring that there are no ground wires or connections anywhere in this section of wiring. Is it safe to assume that the taillight bucket is the ground in this circuit? Is this a grounding issue that I have?

TIA
-carlos
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HIO Silver
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Re: Taillight issue

Post by HIO Silver »

Dim lights are usually a sign of bad grounds... it's backfeeding a ground from somewhere and that's why the light is not fully illuminated.

Second, these trucks are "ground poor". I always recommend checking all harness grounds (eyelets screwed to the body) and then installing additional grounds. One of the most important is the engine to cab bonding strap. One time I was messing with the throttle linkage and had to disconnect the strap. I forgot to reinstall it and the fuel pump would cycle when I turned on the headlights.

Add the following grounds to your truck:

Cab to frame
Bed to frame
Core support to frame
Inner fender to frame

And then verify the following:
Neg terminal on battery to block
Engine to cab bonding strap.

..... all connections should be to very clean metal... I welded bolts to frame and secured the eyelets of 2-gauge and 8-gauge cable/wires. After that, applied Mil-spec Amlguard to stave off corrosion. http://chemsol.com/products/corrosion-p ... -amlguard/

.
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