Climate Control Issues
 

:eek: The compressor is not turning on. If I go to the relays under the
hood
in fusebox, and pull AC relay, then short across pins it does engage
and works. It does not appear to be frozen up, since it works by
bypassing the relay. It was upgraded to R134 3 months ago, but was
operating correctly after conversion.
Dealer has checked pressures to ensure charge was OK, and has spent
time tracing relays and signals but has not been able to isolate the
trouble. No codes show up. Dealer claims to have followed diagnostic
procedure per climate control manual. Last step is the ECU!!! I do
not
want to pay for this not knowing if it is the fix.
Has anyone else had a problem with climate control signals not
engaging compressor? any hints, fusible links, ground wire issues,
etc? Any suggestions to diagnose before replacement?

Might have a second opinion made on the correct pressures and if found o.k. check the trinary switch.

Check the freon again. The compressor will not turn on without it (this is a saftey feature)

I'd try what was suggested above, then before spending $$ to swap out parts randomly, check the ECU and climate control computer operation. The climate control system sends a signal to the ECU, which in turn draws the wire to the compressor clutch to ground to engage.

Reaper has an FTP site (http://reaper450128.homeftp.net/servicecd.htm) with two files that need to be downloaded to troubleshoot the system: a) Automatic Climate Control (troubleshooting and computer voltages), and b) J-Pin Voltage Charts (this has the ECU signal line voltages).

If it turns out to be an ECU problem, I can help. It's relatively cheap (less than $5), but it requires wiring surgery and you lose the ECU cutout of the compressor during WOT - I would prefer you look around for a used ECU - I found one locally for $45.

thanks for the suggestions and links
 

I have some homework to do to follow up on these suggestions; thanks for the help. I will repost wehn I get some of this testing done. :)