Liberty02sport wrote:
Don't know if this will help you or not.... but the wife's '99 wrangler did about the same thing and after replacing the flasher relay and the bulbs in the tail light housing found out it was the switch that was causing it.
Almost same symptoms as yours. When the left turn signal was on and the brake was applied the turn signal light on the dash stopped flashing and so did the turn signal. Try wiggling the switch a bit when this happen and see if everything returns to normal. IIRC the reason for this is the contacts inside the switch get bent a bit over time from people turning the signal on with a little too much force (i.e. dropping the hand from the wheel and letting it smack the signal on).
If that's not the cause you may have to start looking for a intermittent short somewhere.
This was my original thought, until I noticed that the turn signals, reverse lights and brake lights are all affected, and they are all seperate bulbs, wranglers share a common bulb for the turn and brake. Im almost positive that its gonna be the assemblys circuit board inside the light. Especially since the problem stopped with a good tap to the housing. I think the turn signal indicator is lighting from a bleed over from the reverse or brake lights. which would indicate a short between said wires. When the problem starts again im gonna take some voltage readings to verify its the housing and not damaged/chaffed wires somewhere.