I just installed heated explorer seats in my truck and both seats work, but I am having problems with the heaters. I wired the two seats together in T and then brought the single wire to a relay. The relay has battery power and has switched power from the radio. When I first tested them the driver side switch lit up but the passenger had nothing. Now the drivers will flash quick and go out. It will only do it once until you cycle the key again. The relay is hooked up correctly, no fuses are blown. I don't know where to look next. Maybe a bad ground? I also checked for power at the passenger side switch and 2 of the 5 terminals have 12v I don't know which terminals are which, but there is power. The wire I used coming off each seat is 12gauge and where they join is 10gauge. Could the wire size cause a problem with too much resistance and not get enough power to the heaters. Also each heater has a separate constant hot from the battery. The wires that are T'd together are the switched power source. If you have any idea what I could have did wrong that would help me out a lot.

Thanks,
Jason

 

You need to connect 3 wires for the seat heaters. The factory Explorer installation does not use any relays - switching is done in the heater control module.

light blue/white: constant hot 30A fuse
gray/yellow: hot with ignition on 7.5A fuse
black: ground

 

Is the ground the same ground that the seats use for the power adjustments or is there a separate ground? I used a relay because I used switched power from the radio and didn't want to pull too much power from that little wire, is that ok?

Thanks,
Jason

 

In the original Explorer configuration, a heavy 30 amp circuit that is always hot is used for both heating elements. The keyed power for the switches and module electronics comes from a separate 7.5A fuse and requires no relay.

I suspect that the motor and heater grounds are spliced together in each seat harness but the wiring diagram doesn't show it one way or the other. You should be able to trace the motor ground back into the seat and check to see if it has a branch to the heater module.

 

Thanks Bob,

I overlooked something and got them both working great. It is not a good idea to work on something 14 hrs straight with no breaks. I must have been a little tired towards the end of the night. Now the fun part of putting the interior back together. I appreciate your help greatly.

Thanks,

Jason