2005 Sierra Crew Door Lock Issue

[tonym]

Hello,

 

I have recently found in my sierra 1500 crew cab that when I lock my power door locks, the the rear door locks do not lock. If they are locked manually they will unlock with the button and keyfob but will not lock. ANy suggestions on where to start?

 

Thanks

 

tonym

[atboley]

in the left i/p fuse block there are 2 relays named, door lock relay and unlock relay(or somthin like that), they are right next to eachother... you may only need to replace one of them but i replace both of them, if you just swap the relays you will notice that the rear doors will work the opposite(insted of only locking, they will only unlock)... just replace both those relays and it will fix it, i seen that problem many a times...

[tonym]

in the left i/p fuse block there are 2 relays named, door lock relay and unlock relay(or somthin like that), they are right next to eachother... you may only need to replace one of them but i replace both of them, if you just swap the relays you will notice that the rear doors will work the opposite(insted of only locking, they will only unlock)... just replace both those relays and it will fix it, i seen that problem many a times...

 

You were right on. THanks alot!

[uplinker]

I am having the same problems with my 2004 Sierra Crew rear door locks, only I tried replacing both relays and after a few weeks the problem returned. Anyone have any other suggestions. A fuse block problem maybe? thanks!