Hi on my GF's 1991 ford ranger the tail lights are being wierd

1. the running lights in the rear wont turn on.
2.break lights work when running lights are off
3. when running light is suppose to be on break lights wont work.
4. when either turn signal is on both lights flash.
5. when turn signal is on, breaks pushed, that side glows bright and stays on, while other side is dark.
6.no reverse lights.

so far i grounded the ground wire near the plug where it veers off to both sides, and to the plate lights, right when it becomes one wire, about a foot before the rear. hooked that directly to the frame. nothing

fuses under the dash are good.

replaced the lights in the rear tonight, not the reverse lights though.

changed the blinker relay (the thing that makes the clicking noise)

umm tahts all i can think of as of now. any ideas people, its got me stumped at the moment

thanks

 

Disconnect the harness to the rear lights.Then check to be sure the front running and signals are working.If they are, the problem is in the harness or sockets.Most likely a shorted socket .If they don't it's probably in the signal switch.

 

it seems to be everything at the rear of the truck, becacues the lights up front work fine, running and turnsignals.

how would the sockets affect both of the lights like that?

It use to have a trailer harness back there, but we took that off, and hooked it back up with out that, and the problem still was there.

 

Do you have a 2 or 3 bulb taillight setup ?
ie;
1 bulb stop , turn ,tail, 1 bulb backup
or
1 bulb stop/tail, 1 bulb turn, 1 bulb backup

Sockets tend to corrode inside and cause strange problems.Say for instance the ground in stop/tail socket corrodes off on the left socket , power to the left brake lamp will go through the brake filament , then through the tail filament , through the harness to the right tail lamp filament , then to ground.
In actuality electric current (electrons are negatively charged) flows from the chassis ground , through a load (starter motor,lights,radio,etc..) to the positive side of the battery.
However thinking in those terms tends to confuse people even more.

But anyway
Double check the harness from the sockets as far as you can forward for any cracks,breaks.chafing,old electricle tape that may be hiding some nasty surprize,a glob of silicone,nails(yes I've found a nail embedded in one).
You should find a plug in the harness on the inside DS framerail around the area of the axle.Pull it apart and look closely for any rust/corrosion inside.Hell just spray some WD40/PB blaster in it anyway and work it together a few times to be sure.

 

Did you ever find the problem? I'm having the exact same issues. I do not see any trace of a ground on the frame