OK here goes! I have a 97 Blazer 2 door! It keeps locking itself then umlocking! I can't get it to stop. I can't figure out which fuse to pull and it is driving me nuts! If anyone can help that would be great. Oh and I thought it was the #7 fuse but it still does it with the fuse out!

 

is it keyless entry? i am only guessing but maybe the receiver for the keyless is shorting out??
it is located under driverside of dash just behind the obd scanner port.

********now i dont know 97's (i am going off what my 99 has)**************

 

opps forgot to add that. it is not a keyless entry

 

do you have an after market alarm system in the truck?

 

Nope it's all stock

 

try unplugging the driver side lock switch?

 

yea i was gonna say just check the connection of the driver side lock, unplug it and plug it back in, if that doesnt do anything then i dont know what to tell ya

 

I just went through all the diagrams for 99 and {without spending hours trying to follow the #@@#@@# alldata charts} I see no single point or wire that could cause both random lock then unlock.
Factory remote entry wouldnt even cause that IMO. So unless there's an aftermarket box hidden somewhere, chances are very high it's a broken switch.
>>>> An add'l symptom to look for would be hearing lock sol's without any change <<<<

A very long shot would be the data link to the BCM rubbing against grd just happening on the right digital bit sequence.

BTW: how do you know you dont have keyless entry?

 

My Mom was the original owner and it never had keyless entry

 

My 97 developed this problem. My son and I were at a Boyscout function. Anyone who has been in scouting knows that the one time you forget rain gear, ITS GONNA RAIN! I popped the hatch on my Blazer and we stood underneath it. Next thing I know, the locks starting having seizures! Does the keyed window lock have electrics going to it? I believe so, but I have never had a new Blazer so my rear lock cylinder has never worked. My guess was that water has gotten into the rear gate and shorted something out in there. I pulled the lock relay in the right side dash to get it to behave. About a week later after some good dry hot weather i plugged it back in. Seems to be fine ever since.

Pettyfog - I have a 97, 98, and 00 Blazer. Had a 99 Blazer. I printed off year specific wiring diagrams for each truck. Why? Because for some reason, GM couldnt leave well enough alone! If I get lazy and use the wrong diagram for the wrong year, I always seem to get burned. Just keep that in mind tracing diagrams. Have a good one!