What do the relays do?

[muddypsd]

I was looking under the hood at the two relay boxes next to the power distrbution box and I discoverd that the two relays in the box closest to the firewalll were missing, so I pulled a relay from the other box that is closer to the air box and I did some poking around with my meter and I relized that one relay made my back-up lights circut work for the trailer and the other made the 12v circut work on the trailer. So now I know that I need to get a couple realys to at least get my back-up lights to work on my trailer.

So all of this leads to is I now know what the realays do in the box closest to the firewall, but I dont know what the realys do in the box closest to the airbox.

Anybody know?

[dzl wannabe]

Probably ESOF relays.

[function12]

I believe the 2000 came with a relay pack that you could install them if you used a trailer break system.

[muddypsd]

Could be. I didn't check to see if my trailer brakes quit working when I took a relay from the pack from the one closest to the air box