5v sources on 1988 ranger?

[88xltranger]

 

[RonD]

"Only place i have 5v is on the signal side of the rear lights"

???
So BOTH rear brake lights glow with key on

Rear lights share brake/turn on one filament and when turn stalk is in neutral position both are connected to brake pedal switch via multi-function switch

But brake pedal switch has 12v all the time, not just key on, so not coming from that

If possible unplug the multi-function switch then turn on the key and see if just one of the rear bulbs light up
That can tell you which wire, orange/blue(right) or green/orange(left) has the 5volts, or if no light then its coming from multi-function switch

 

[88xltranger]

Correct, both sides are showing 5v. Sometimes they both light up, sometimes only one.
When its only one, if I unplug the lit bulb, the other side will light up.
I will unplug the multifunction switch in the morning but I believe that is why I replaced it already. So far nothing I have poked or prodded or replaced has made any change.
The ONLY thing that made any significant change is unplugging the rear harness from under the hood(8 pin connector). At that point all exterior lights on the front half of the truck light(dimly) up with key on.

 

[88xltranger]

From my experience it seems like a ground issue but everywhere that should be ground, is a good ground.

 

[RonD]

Well the lights would be "the good ground", and another, key on, system is using them as the ground, which causes them to light up

Which is why pulling fuses should have worked, if it was a Ground issue

The ignition switch doesn't have a fuse, just a fusible link, and probably wouldn't help in any case since you already know its a key on issue