I just returned from a seventy mile racing trip today and when I went to unhook my trailer I had no power to my electric tongue jack. I checked trailer wiring and plug but couldn't find anything wrong, went to house to get a drink of water when I returned noticed power was on at jack. I thought maybe a breaker or relay had interrupted the power for some reason. So I pulled the cover off of the power distribution center (to the rear of the driver side battery) and was looking at fuses and relays and the three relays closest to the fender were so hot you couldn't hold your hand on them. The relays according to the cover are; starter, fuel pump and ASD from left to right. They shouldn't have anything to do with the trailer wiring but what's up with them being so hot? Am I getting ready to have a problem or is something already wrong ? Please help

 

O K nobody knows! Thanks anyway

 

Easy buddy, an odd problem like this bound to get responses after a while.

I personally have never seen a temperature sensitive relay. In my experience (U.S. Coast Guard electronics technician) I have only seen relays that work, or don't work.

 

Well maybe it's normal doesn't seem to be affecting anything

 

I'd replace the relays just for good measure or at least swap them with other relays from the PDC that have the same rating- so you can isolate whether it'S the relay itself or if it's overloaded.
The only heat source in the relay I can imagine is the contacts going bad while pulling a lot of amps. Did you check your fuses and see whether they are the right size for the application and not some 40A in a slot designated for 5A? I get customers cars all the time with the weirdest issues and in a lot of cases if you put in the right fuse it will pop instantly and show you which circuit is faulty- but with a bigger fuse the problem will show somewhere up the line.

AlpineRAM

 

I think it's normal.
Most of the relays I deal with, automotive and other, get hot when triggered for long periods. It's the coil making heat when energized.

 

Thanks alpine ram , and yes I did check the fuses and none were blown or in the wrong places. The only problem I encountered like I said in my original post was I lost power to my trailer jack for a short period.

 

Thanks Infidel, I've been on a recent are farther trip than the last and haven't had any problems, but I'm still skeptical .

 

The relays on my Audi run very hot as well. However one in particular had an infrequent tendency not to shut the AC cooling fan off. Killed my battery twice. I did replace both relays in that circuit but they also run hot.

If the trailer wiring is fused by one of the square fuses in the power distribution center, you might want to replace it. I just went through a couple of days of fighting with the ign. switch fuse on mine. Started the truck and it died when I put it into gear. Ignition switch dead, everything off of the ignition switch dead. Got my test light out and hot lead to the switch was dead. Checked the fuse and it was not blown. Closed the door, went inside to look at the forum, went back out checked the hot lead again and it was hot. Pulled the fuse out. When in normal position it looked perfectly fine. When I tilted it slightly, you could see a slight gap right at the T. A closer look showed a little arcing across the T. $1.78 at autozone cured it.