I've got a 1998 F150 5.4 Short Bed Super Cab, I pull a 14k GVW PJ Gooseneck Implement trailer. The truck handles the loads pretty good, much better after I installed helper springs. However, I have a problem....I installed a trailer brake unit in the truck (with 10k loads you need it) and the brakes work great, however when the truck in "on" (ignition key) and I turn on the 4-way flashers my brakes are activiated, if the truck is "off" (ignition key) the brakes are not activiated. I have been ALL over the trailer hookup on the truck and no shortes were found, this happens when NO trailer is hooked up or when I have my trailer hooked up -- so I know its not the trailer. I am at my wits end at the moment on where to look next. It seems to be getting power from some "live" wire but not sure how that is involved with the trailer brake unit. I bought an adapter and trailer brake unit together and simply plugged it in, so no chance for me to mess up the wires.

Any help would be greatly appreciated.

Thanks!
Kevin

9 bales of hay on this load (lost one 2 miles back), before helper springs.
http://kevsapt.com/kevin/Pics_2004/sm_loadofhay04.JPG

 

Do you have a test light or meter?

Is the trailer female plug in the bed or next to the hitch or both?

With trailer attached, check the 7 pin connector on the rear of the truck. If you have one in the bed, check it too. It may have been wired wrong.

11:00 position should only be hot with lights turned on
1:00 position should only be hot while key is turned on
3:00 position should flash with right turn signal and come on when the brake pedal is applied
5:00 position should be hot all the time (brakes) if you have a brake controller
7:00 position should be cold and conductive with the ground
9:00 position should flash with left turn signal and come on when the brake pedal is applied
Center pin should be hot always (auxilery power)

If your truck checks out it is in the trailer.

Is sounds like a turn signal/brake light wire in the trailer is shorting or connected to the trailer brakes. My first thought is always the trailer plug to look for a single strand of loose copper shorting. If all looks good, try switching on the trailer the ground and the electric trailer brake wires. I have seen this before as the culpret.

Tell us what you find........Good luck

 

http://www.tekonsha.com/tebcpulseprev.html

 

I have not had time to test again as provided, however I've rulled out that its a trailer issue as the same thing happens when the trailer is not connected to the truck. The light connector is in the bumper, not my bed.

Per the pulse device, would that be the issue, seen something about a range of years on Ford pickups 1989-1991, however I was not sure if that was talking about implemeting that or the need for that?

If the pulse device will fix it I'll eagerly install one, as I want/need to be able to use my 4-ways without burning up my trailer brakes and wrecking in the process.

 

I bought a DrawTitle #5501 Pulse Preventor and just got done "installing it". However it does not have the desired affect, it has no affect to be honest.

I cut the cold side of the stop light switch and hooked up the yellow wire to it, then hooked the brown wire to the existing wire going to the lights. I have a Hoppy Brakeforce EBC with a connector so no wires to cut. I tested the rear of the truck and the trailer brakes are still activated when I use my 4-ways.

Any help woudl eb grealty appreciated...as this is a simple install that should not cause issues.

Thanks,
Kevin

 

I figured out what I did wrong....I forgot to cut the EBC wire and hook it into the pulse preventer, thus no change in how things worked. Duuh. So, I made that change and life is great -- Thanks!