Mine is a 1987. I am not sure if anyone here knows from bone yard shopping, if the factory plug for the factory module is pre-wired under the center console on the Blazers that did not come with factory key-less entry but have factory power door locks?

 

Hey cliff70chevy, I'm probably not much help here because I don't know anything except what I found in the 1994 service manual. Did 1987 even have remote keyless entry as an option? I skimmed this document and didn't see a mention of keyless entry, but maybe I skimmed too fast: https://www.gmheritagecenter.com/doc...-10-Blazer.pdf

I wonder how different the '94 circuit is from the '87 circuit. If the power door lock harness is the same, you could probably make an adapter harness like I did. It would probably be a little different from mine though.

 

Hi Doug,

That information is amazing. What state are you located in.

I know I can put in an aftermarket alarm with keyless entry. I was kind of hoping that since mine is a Tahoe with PWR locks that keyless entry might have been an option. I thought if it was an option, I was hoping that it might be pre wired (so I could just do Plug and Play). One day I might take off the center console and see for myself if I do not find out here.

Mine came from an estate sale. I got it with the original title from the original owner that died. It is 4X4 with 62K unmolested garage kept miles. The 2.8 V6 is a slug so my future plans are for a VW 1.9 TDI Diesel. I think everyone here will appreciate your post.

Thank you,
Cliff

 

Hey Cliff,

I'm in Oregon. Wow, that's incredible mileage, especially considering its age. Mine has less than 130k and I thought that was good!

I can't speak for how good the 1987 S-series service manual is, but what I would suggest is trying to get ahold of a copy. Then you can see for yourself how everything was wired, and possibly get part numbers for any connectors. At least on the 1994 4-doors, the keyless entry module is pretty basic. It just inserts itself into the same signals that the door lock/unlock switches use, and then isolates the driver's door motor from the others, providing its own relay just for unlocking that door. It also has a relay for the rear window release. I'm pretty sure it's possible to do the same wiring on yours even if you don't have the factory wiring for keyless entry. It's just a matter of figuring out where to hook in...I was really happy with the way I did it because I didn't cut a single wire in the factory harness. I'm curious just how much GM changed the power door lock door connector from 1987 to 1994.

 

Hi Doug,
I don't know how much of a difference there is between the different years, but I do know that the switches on my doors are five pin (I guess some other years are 3 pin).

I also found out when my Power Door Locks stopped working recently on my 1987, that there are are a few years where they do not make replacement switches and 1987 is one of them (just my luck as both of my switches were bad). I found one NOS passenger side switch on line that was cheap. I also ended up paying $150.00 for a used one, from a salvage yard for the drivers side (they made sure to let me know they were sticking it to me because they knew I could not get a new, or reproduction one).

I also found out that if I ever need to get another switch in the future a 1988-1989 K-Series Blazer switch can be made to fit. The K Series switches were designed to be mounted vertical instead of horizontal so the graphics on the K Series switch will be clocked side ways. After you separate the outer surround portion of the old switch and the outer surround portion of the K Series switch (which is larger and will not fit), you can cannibalize the outer surround from the old switch with a Dremmel and some JB Weld and mate the old outer portion of the old bad switch with the complete inner portion of the K series switch. The legend image on the K series switch will be sideways and the pins will NOT stick out far enough, but after you do a little talented surgery it will work and fit in the door just fine if needed.