87 blazer with 89 motor and wiring harness

[indyrenegade4x4]

The 89 wiring harness from a donor blazer will not screw into my 87 firewall harness under hood. Any idea on how I can make this work?

[tvblazer78]

You got me on that one, Can anyone help him out?

[kevinr1970]

I can't say this with certainty, but I think you will need to use the harness from your '87.
I believe the harness will control all the right things though.

[indyrenegade4x4]

did chevy change the fuse
block(wire block) on the firewall from 1987 to 1989 models. The only thing i can think of is in 88 or 89 they added something to the outside wire block under hood.

[kevinr1970]

I recently put a '89-91 clip on my '87 crewcab.
The block end of the harness is very different. I had to cut the block-end off and splice in the block-end of my '87 harness.

Why are you needing to swap the harness?
If you are in need of replacing your exising harness you can do a lot of cutting and splicing like I did or better yet, find another donor harness from a more similar year.

[indyrenegade4x4]

i bought it and the guy got one out of 89 with computer etc and thought he could take harness off and screw 89 harness in. I hate to splice but with little time, solder and shrink tube it will work. It is going to be used for mainly offroad.