Hello, I put a receiver hitch on my 91 XJ and installed the E-Trailer plug-N-play 4 way behind the spare tire, also got a autozone 10 lamp loud click flasher and installed it. When I hook-up the trailer the tail lights are normal and break lights are normal. The turn signals start the quick, weak flashing on either side like I have a light duty flasher. Now the BUT... when I press on the brakes the turn signals go into normal operation. When I take my foot of the brake they return to the fast, weak flash. Thought it might be a ground problem but it does it with the trailer on the hitch or off the hitch. All lights seem to be working. I know this is probably so simple that I'm going to be embarrassed. Appreciate any ideas. thanks

 

Try putting in a known good stock flasher and see what you get.

 

Make sure you have a good ground.

 

Got a voltmeter and a helper?

 

If the lights are broken, how can they be normal?

(HINT: You have turn signals and brake lights. Yes, spelling does matter.)


Are you counting on the trailer being on the hitch to make a ground connection to the vehicle?

If so, stop that. That's not a reliable ground at all. You need a proper connection to ground from the trailer, through a light connector, to the vehicle's chassis. If you don't have that, expect all manner of strange and erratic behavior.

That aside for the moment, please describe how the lights on the Jeep work when the trailer is completely disconnected. Do you have any problems? Or does everything work normally when the trailer is out of the picture?

 

For one thing, when you add any light in parallel to the existing light, you double the current flowing in the circuit. That will make any flasher flash twice as fast. For another it sounds like you have the turn signals in the trailer connected to the brake lights. Wiring error.? This really is a job for someone with some electrical savvy and a good working VOM, Hope this helps.

 

It won't necessarily double it, it will depend on the wattage of each bulb involved. The current draw of each device is added when in parallel not multiplied.

 

[QUOTE=cliffy;3235233]It won't necessarily double it, it will depend on the wattage of each bulb involved. The current draw of each device is added when in parallel not multiplied.[/QUOTE
True but in this case a tail light bulb added to a tail light bulb is doubling the current, as stated.