Gold Lifetime Member
Join Date: Apr 1999
Location: Vancouver Island, Canada
I have just gone through the same thing after switching to led lights throughout the whole vehical!
To address your rear lights and one side going out or going dim? The first thing to check is that the bulb socket is clean without any corrossion in the bulb socket. Clean all of them well and add some electrical grease to ensure you hold corrosion at bay for the future.
If using the original sockets you will find that they can be finiky in making the proper contact with the housing and getting proper ground. I replaced mine with metal ford sockets that make great contact and do not pop out as many of these cars seem to do on their own or just enough to cause ground issues with the socket! (regardless of which sockets you use make sure that you clean up the lip on the housings that makes contact with the socket) This will take care of any concerns with wiring and ground interruptions to the back.
To throw a curve into it after reading articals on the issues it was pointed out that if bulbs are dimming on one side of the vehical you want to check the opposite side for grounds and bulb malfunction as it can/will play into having the circuit completed. This can be validated if your dash lights for the blinkers has one flashing faster than the other or just remains lit and no flashing happening. ( What are the dash lights showing as all this is happening?)
Regarldless i believe you are still having ground issues in the sockets themselves that you are using or to their contact with the housing.
67 RSSS Van Nuys, 4th week Sept,1966
ps,tilt,headrest,spd warn,pw,am/fm,delux int,
remote mirror,rear defrost,tint glass.etc...
TKO 600 Extreme,12bolt 3:73 gears.