initiald843

today i started my truck and no low beams. i have hid's w/ a relay harness.
i checked the factory plug and i have no power going to the low side. when i hit the high beams i have 12v. checked the fuse. is this a bad headlight switch or the power distribution box? need quick help before i go tearing everything apart.

thanks in advance.

MikeyB

Did you install a load resistor on the factory low beam connection? If not you will need a 6 ohm 50w resistor tied from the OEM low beam wire to ground. The FCM needs to see a load on the low beam circuit or it will shut the system off.

MikeyB

initiald843

mikey...does the resistor go inline with the power wire?

initiald843

also...i tried to put the regular halogen bulb in and still no low beam. is there a reset i need to do?

MikeyB

The resistor is tied from power to a ground.

Did you plugged in the halogen bulb on the unused OEM connector, but still had the HID plugged in to the other side?

MikeyB

initiald843

yes. i still had the hid plugged in on the other side

initiald843

how do i reset the fcm. i plugged in both the regular halogens and the lights still dont work

MikeyB

I think the only way to reset the FCM is to have the dealer do it. First I would try disconnecting both batteries for about 5 minutes before taking it in.

But make sure you don't have any blown fuses before taking the truck to the dealer.

MikeyB

Mexstan

When I was installing my HIDīs I did not know about the way the FCM reads the load and discovered the hard way that there is no old fashioned fuse for the headlights after I lost power to the lights and had to figure out for myself what the problem was. I just disconnected both batteries for a while and everything rest itself.
In my case I did not install a resistor, but instead installed a set of driving lights in my bumper and used those to fool the FCM. Then I installed a relay for the power to the HIDīs and ran a wire via a fuse direct from one of the batteries.