lights blinking after trailer is plugged in...

[mastiffkevin]

Hi I just found a problem with my 71 F100.. I have never noticed it before, but then again i usually only pull my trailer during the day! I had plugged the trailer lights in and was loading things and had the headlights on. after about 5 min. the lights began intermittently blinking.. and not just the marker lights, but the dash lights also! Could this be a weak relay? I looked at the wiring diagram for 70 and couldn't see a turn signal blinker relay.. did they use the emergency one for both? I'm supposed to leave for Florida day after tomorrow and need to figure this one out! Any ideas would be greatly appreciated!!

[fordman]

the headlight switch has breaker inside of it. it was tripping off and on because of the load of extra trailer running and tail lights that were added to light up on the trailer. that means the headlight swithc is weak enough it won't handle the load of the extra lights. so you need a new switch to make up for the older weaker switch.

[mastiffkevin]

the headlight switch has breaker inside of it. it was tripping off and on because of the load of extra trailer running and tail lights that were added to light up on the trailer. that means the headlight swithc is weak enough it won't handle the load of the extra lights. so you need a new switch to make up for the older weaker switch.

Hmm, now this is definitely a problem, cause it's a new switch! LOL it's an enclosed trailer with marker lights all over it.. i wonder if removing some of the marker bulbs would stop it? does anyone make a trailer wiring kit that would take the burden of those lights off the switch?

[ForingaMex]

It shouldn't be too hard to rig up your own wiring with a relay. You could put the relay under the hood, close to the battery and take power from the battery. Tap into a wire that is hot when the parking lights are on to trigger the relay and than run a nice heavy wire from the relay to the trailer plug all the way in the back of the truck. Someone will be able to give you more detailed info. Good luck.
Jake

[basketcase0302]

I looked at the wiring diagram for 70 and couldn't see a turn signal blinker relay.. did they use the emergency one for both?

There are two flashers in our trucks, (or at least in my 71'). The turn signal flasher is under the dash on the drivers side close to the kick panel. The emergency flasher, (if it's still in place) is in a "clip" on the right side of the steering column behind the dash.

My build: http://www.fordification.com/forum/view ... 22&t=46251 includes a very slick wiring upgrade to the rear lighting to solve the very same issue you speak of. I'm about one week from finishing that aspect of the build, (so I can't actually show you yet). It's a pretty simple upgrade to pull the circuit from the solenoid (fused-preferably circuit breaker type) to the underhood relays. Then use the existing running light and turn signal wiring to switch the relays. You can use KC type lighting relays if you can't get anything else. And increase your wire size.
Yes, it would probably help to remove a couple of bulbs from the circuit also (but maybe not enough due to our old/tired wiring).

Hope it helps!

[knightfire83]

Idea: Change all the trailer running light bulbs from standard to LED versions.

All of those put together will run on less than the current needed to run 1 regular side marker 168/192 bulb.