95 Buick Lesabre A/C compressor bypass pulley

[tuckerman22]

Hi All,
I’ve looked high and low for a thread on just bypassing the A/C compressor and have had no luck finding one so here it goes. The compressor locked up (bearings) on my son’s car 95 Lesabre and completely stopped the started from rotating the engine. Instead replacing the compressor I opted to remove it and install a bypass pulley. This was a pretty strait forward process but when I started the car I had a check engine light so I had it scanned and had the following codes:
P1640 QDM1 failure P1670 QDM4 failure
P1406 EGR valve pintle position circuit
This is my son’s car and he can’t remember if the ck engine light was on before the A/C compressor locked up. So, my question is did removing the A/C compressor from the wireing harness cause these codes? If so, do I have to jump the compressor wires? If the codes are not a result of removing the compressor what do you think it could be?

[maxwedge]

Welcome to AF. The pcm sees an incorrect egr position based on it's commands, so it could be bad or carboned up egr, the quad driver controls high load solenoids, I do not believe the a/c has anything to do with these codes, you will need a comprehensive wiring diagram to see what quad driver 1 and 4 controls. Just make sure the are no obvious pinched shorted wires anywhere around under the hood.

[big white bufflo]

doorman makes a bypass pully for this application i did my 92 and it works great look at rockauto and try napa or autovalue for this part and i just left all my wires hangging with no troubles