7-pole trailer wiring: relays needed?

[Bob Barry]

I finally bolted on the hitch receiver to my rear I-beam bumper, and just have to finish the reinforcement brackets to tow my parts to the big Thompson Speedway swapmeet in CT this weekend.

Next step is the wiring for the trailer. The stock relay bank I have available is rusted out, and I could fabricate a new backplate and hunt down replacement relays, I suppose.

But, is it really necessary? Is the sole purpose of that relay bank to permit the trailer-lights to work without screwing up the delay on the stock flasher can?

If so, then I'm thinking I can do away with the relays, since I have that electronic flasher-can that automatically adjusts to different loads; it should be able to run trailer lights just fine.

OTOH, if the extra load from the trailer lights will draw too much current for the stock wiring, then I don't want to burn up my harness while towing.

I suspect that the relays aren't there to handle the load, since most harness adapter kits for newer trucks don't use any kind of relay bank.

Any regular towers or electrical folks out there who know the real deal on this question?

[jeepbob]

Bob,
The newer factory wired rigs (Fords for ex)usually have the relays under the hood. If you are not running a trailer that has a bunch of running lights you should be fine. If you are running a full set of running lights and double tail lights I would go with a relay to ease the strain on the head light switch. The factory trailer harness on my 78 did not have relays. If you are running a Chryco FSJ, you are on your own as I do not know what evilness was done there

[Bob Barry]

One saving grace is that I'm running my headlights through relays, and my front marker lights are very small, so the headlight switch doesn't see much load at all. I've got the spare trailer harness, so I'll just hook it up to a new receptacle and hope for the best.