Dash lights and odometer pulsate when pressing on brakes

tonkaman3

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So I installed a trailer hitch on my 06 TJ, also the plug and play harness, both from Quadratec. All the lights work properly but when I press on the brakes all my dash lights and odometer readout pulsate? is this normal? I also recently installed all LED bulbs and an electronic flasher, could that be the problem? Any help would be greatly appreciated!
 
I definitely lean towards the LED's. Just for grins, take them and step on the brake. And/or you could put the incandescent bulbs back in. The brake/turn bulbs are (or should be) indexed. One pin on the side of the base is closer to the end than the other.
 
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there's all kinds of funky electrical gremlins after installing LED. My odometer flashes in sync with my turn signals now (but only when the headlights are off...headlights or running light on, no flash).

do your dash lights pulse when you brake while the trailer harness is contacted to the trailer or all the time while braking unconnected?
 
It's related to the LED install. Which all bulbs did you replace with LEDs?

The front fender flare side markers by chance?
 
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It's related to the LED install. Which all bulbs did you replace with LEDs?

The front fender flare side markers by chance?
I had this exact issue. Installed LED lights in the side markers and had all kinds of issues. I spent hours trouble shooting only to discover it was the new LED bulbs. Very frustrating!
 
there's all kinds of funky electrical gremlins after installing LED. My odometer flashes in sync with my turn signals now (but only when the headlights are off...headlights or running light on, no flash).

do your dash lights pulse when you brake while the trailer harness is contacted to the trailer or all the time while braking unconnected?
Yes, it only happens when the trailer is connected, otherwise everything works normally.
 
It's related to the LED install. Which all bulbs did you replace with LEDs?

The front fender flare side markers by chance?
I did put LEDs in the side markers, and I did read the post about them causing problems so I switched them back to incandescents, but still have the issue. Could I be dealing with a bad flasher relay? The bulbs and relay came from Super Bright LED's.
 
I did put LEDs in the side markers, and I did read the post about them causing problems so I switched them back to incandescents, but still have the issue. Could I be dealing with a bad flasher relay? The bulbs and relay came from Super Bright LED's.

It would certainly be interesting to switch everything back to stock and see if the problem persists. While I'm not 100% sure what it is, I'm almost certain it has something to do with LEDs or the flasher relay itself.
 
Connecting the trailer lights to the Jeep places incandescent bulbs in parallel with your Jeep's LED bulbs. I can see that causing weird problems. As said above replacing the TJ's incandescent bulbs with LEDs can cause several problems. That's because some Jeep lighting circuits depend on the ability of incandescent bulbs to conduct in both directions. LED bulbs only conduct in one direction. The only sure way I'm aware of to fix that is to install a bridge rectifier at each of several of the bulb locations. All the effort and expertise needed, which I have, to make the TJ's lighting circuits work properly with LED bulbs make LED bulbs not worth the effort. I know how but I still won't convert all the bulbs to LED. The benefits of LED bulbs don't outweigh their drawbacks, where a TJ is concerned, in my view.
 
Connecting the trailer lights to the Jeep places incandescent bulbs in parallel with your Jeep's LED bulbs. I can see that causing weird problems. As said above replacing the TJ's incandescent bulbs with LEDs can cause several problems. That's because some Jeep lighting circuits depend on the ability of incandescent bulbs to conduct in both directions. LED bulbs only conduct in one direction. The only sure way I'm aware of to fix that is to install a bridge rectifier at each of several of the bulb locations. All the effort and expertise needed, which I have, to make the TJ's lighting circuits work properly with LED bulbs make LED bulbs not worth the effort. I know how but I still won't convert all the bulbs to LED. The benefits of LED bulbs don't outweigh their drawbacks, where a TJ is concerned, in my view.
I must say I'm beginning to agree, it's not worth the hassle.
 
Hi, I'm having the same issue with my 97 TJ. Did you ever find a solution?

I hear a clicking noise coming from the glove box area every time I hit the brakes or use turn signals when the trailer is hooked up. Almost sounds like a relay clicking. Only relay I see in there is working fine and all fuses are in tact. Additionally, when trailer is unplugged I read around 12 volts at the prong using a voltmeter. Trailer plugged in only reading 1 or 2 volts at the trailer rear lights. (Brand new wiring harness for trailer).