Dim Right Turn Signal With Headlamps On

[jleamont]

I want to share a ghost electrical problem that intermittently comes and goes on our coach and the simple fix.

On occasion when I turn on the headlights or marker lights, my right turn signal arrow on the dash would glow dim and I would loose the right rear turn signal in the back.

As soon as I had an opportunity to investigate it was fine . Well it finally broke completely. When I turn on the marker lights and the hazards, none of the turn signal lights in the rear of the coach would blink, (the front signals would blink very slowly) the rear lights would come on bright (separate amber lights on our coach for rear turn). When the right turn signal was on, same result on the right side, left side worked fine.

I figured I had a ground problem in the right turn signal circuit, so I pulled the right lens out, can't find a problem... scratched my head went to the front and as soon as I unsnapped the lamp from the lens it started to blink normally.

I removed the LED bulb and replaced it with a regular 3157A bulb, and it worked fine, put the LED back in blinking slow again , hmm bad LED bulb? I swapped the LED bulb with the left front, it worked fine over there. Plugged the left LED bulb in the right side and it acted up again.

It turned out to be a bad socket ground inside the socket, for some reason the standard light bulb worked and the LED didn't like it. 

One of those problems where you can't see the fault and I had a ground with my volt meter when I Ohm'ed it out. I removed the Ford socket with the attaching plug and replaced it with a splice in one piece socket (GM replacement part). $6.53 at the local auto parts store. 

[obedb]

I installed LED turn signal  lights front and rear on my Star Car (last truck)  and had to use an electronic flasher  to get all to work. Not enough current moving through the standard flasher to make it work.

[dickandlois]

Jleamont,

Good find!

You just have to love where bad grounds can popup and when they are intermittent.

Good luck finding them and the real kicker is that many time when you try to use a meter to read the resistance, just the pressure of the prob hides the problem.

Rich. 

[jleamont]

ObedB, the last coach I put LED lights in the rear and had the same problem, this coach doesn't care if they work or not still flash the same, well unless the ground is open anyway. 

Rich thanks, I tried to clean and reposition the contacts nothing worked (cheap way out). I'm going to be proactive and replace the other side tonight they both looked the same inside so why not.