Adding flashers to truck headache rack

[94BULLITT]

Its hard to say with out seeing it. I would check and make sure you have a good ground but you are probably overloading the flasher.

 

[WM75Guy]

Does it happen when you plug in trailer lights? If not your problem is in the new light and wiring, not the flasher. If you have a thermal flasher like the old Ideal 536 or 537 the more load the faster it heats up and flashes. The light may have a problem causing higher current draw, hence the faster rate. Swap the lights and see if it happens on the left side. An electronic flasher could also correct the problem.

 

[VTFireftr]

It's not the flasher. The F550 comes with a heavy duty flasher.

I would check the grounds on both "add on" lights. If possible, use another source to ground the lights, not the headache rack.

Also, check the lamp inside the "bad" light. The socket may be bad.

Good luck.

 

[Builder]

It gets better. Now the rear turn signal quite working on the same side.

 

[mikehaugen]

I don't think it's the flasher either because most (if not all) vehicles use the same flasher for left and right sides. Does it flash faster as in same pause between flashes but short flash, or is it a short pause and a the same flash time? The flasher is basically a capacitor that gets discharged once it is charged (again if yours is a heavy duty flasher it may not work this way). As the capacitor gets charged the light is off, once it charges it will discharge. The rate of discharge will depend on the resistance of the circuit (more bulbs will allow it to discharge faster and cause a shorter "on" time). The charge (off) time should not change. This should help point you in the right direction.

Also, if both are grounded well to the headache rack then that should not be causing the issue since I would expect the grounding between the rack and truck to cause more problems, but that would cause problems with both.

 

[boggen]

pickup a "multi meter" you can pick them up fairly cheap at most large hardware stores or automotive stores in the electrical section. any were from 10 bucks to 100 bucks. a cheapy for 12v should all you need. and tag the ground and hot wires. for each side, and see if you get the same readings when lights flash.

i am going to say check your flasher unit, under the dash. i would have to look it up myself in how to test a flasher unit. with a multi meter, i have had one side go bad while other side works just fine.

if you have a trailer plug on rear of truck. run the new lights off of it. vs into the actual lights on vehicle. majority of factory wiring to tail lights on rear of vehicle or to the front turn singles on the vehicle itself, are smallest size wire they can get away with. and you could possibly over load the smaller size wire and burn it up / start a fire.

you may have a second flasher unit for trailer connector/plug, or perhaps a couple extra wires coming off of flasher just for a trailer connector. either or, the goal is splitting up how much electricity goes through a single flasher / wire coming off of the flasher.

with your notation of one side went completely dead. you may have left side and right side "fuses" and you might have blown the given side fuse. still would encourage double check flasher.

all the flashers units in vehicles in the past that i have had to replace have always been behind the glove box, on passenger side. and some sort of "removable panel" inside the glove box to get access to flasher unit. though i do remember a couple flashers being just under the dash. (remove under side panels and flashers right there) though that might have been a break controller or a diy job for trailer lights (way to many years ago)

 

[nuffer460]

If your 550 is the 2008 in your profile. It is posible that the lights may draw to much power. On older none computor vehicles they used standard incondecent bulbs. The newer computor controled lights run a different type bulb. They draw less current. I wired up a set of lights to a newer truck and had a similar problem. I finally had to change the lights out for a newer LED type, less current drawing light. It had to do with an unbalanced current draw. It totally freaked out the electrical system. Just a thought. As this problem took me almost two weeks to figure out.

 

[billfires]

On my 2004 F350 the Ford truck builder book says you need to use relays when adding the turn signals for the snow plow. The factory trailer wiring uses relays to power the lights on the trailer. You may be able to use LED lights on the headache rack without relays due to the low power requirements. Bill C

 

[aczlan]

I agree with those who say that they are pulling too much juice. Switch them to LEDs and the problem will probbaly go away.

Aaron Z