Volvo 240 AC notes 1975-1993
1978 New Car Features: Shows console switch control and simple relay (non-electronic) gating compressor with blower control.
1980 shows electronic time delay relay, and thermostatic control added.
By 1982 the new permanent magnet blower is on low speed with key. Sidecar microswitch added for idle speed control. Electronic relay triggered by alternator D+ output.
Following are 1981 wiring diagrams.
Following are wiring diagrams from an 85 AC book.
Solenoid adds air in k-jet without CIS.
Next two drawings are from an 85 wiring diagram manual.
Next two drawings are from a 91 wiring diagram manual.
Quick Reference Parts book (1989) shows three relays for AC
Guts of the electronic relays I have seen.
Some pix of the AC control in a 1989 245
Simplified schematic of 1989 AC
It was apart to troubleshoot intermittent operation. The problem was traced to the sidecar microswitch, riveted to the thermostatic control. Replacing the control is a job, because the cap tube must be dug out of the butyl rubber insulation on the evaporator outlet.
1993 AC is the same as the 91 depicted above, using CCOT but factory charged with R134A. Check back here for updates. email: benstein at cleanflametrap dot com
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