adding a tailgate lock.

I recently installed a lock motor in the tailgate of my 2011 Chevy Colorado. I used a DEI relay module and lock motor. I wired the relay as normal and used the lock / unlock wires coming out of the door to trigger the relays.

Everything seemed to work fine until I noticed the switch on the door would not lock them anymore. The factory remote still works fine. If I disconnect the lock trigger wire from the realy module the door switches start working again.

My guess is that power is feeding across the relay coil and preventing the door switch from locking. Can a diode across pins 85 & 86 on the relays stop this? Would a resistor on the trigger wire work? I think I am on thge right track but want to be sure.

Probably but you should always diode the relays.

You should connect the relay module right to the door lock actuator wires. It sounds like you have connected them to the door lock switch, which most likely goes to a BCM input. I would guess, without actually messing with it, that the switch is a low current input and voltage is bleeding through the relay and basically "holding" the switch down constantly. A diode across the coil will not fix this. Does the tailgate lock even work setup like this?Kevin Pierson

Connecting to the actuator wires was of course the solution. It occured to me yesterday morning but thank you for the responses. It has been years since I have done this type of thing and door switches were not so sensitive then.

Yes, the tailgate lock worked. The remote keyleass also worked. Just the switch on the door was affected. Works perfectly now.

I also installed a 530T window controller if anyone is interested. It was quite a task but works awesome and is tied to the RKE.

Thank you.