sgreen Posted August 11, 2003 Share Posted August 11, 2003 i have a 91 ls 400 which is blowing warm air. i did the test by pressing AUTO and REC. i saw two codes, 21 and 88. i understand about the 21, but does anyone know what the 88 means? Also, i read in prior posts about two electric fans coming on. are these the fans that are closer to the engine or the ones behind the grill. the A/C worked fine last year. the only work performed under the hood was the 85K service and also the battery was replaced during winter. thanks in advance for any help. sg Quote Link to comment Share on other sites More sharing options...
Rich Sweitzer Posted August 11, 2003 Share Posted August 11, 2003 I think that the "88" is just a display segment test. The first part of the test routine on the AC ECU tests the display and the lamps. The second part of the test displays error codes and the third part runs the fan and damper doors through their paces. As to the fans, there are three associated with the radiator and AC condenser. One fan sits between the radiator and the engine and is driven by the engine through the auxiliary drive belt. This fan is shrouded and is coupled to its drive source through a hydraulic clutch. The other two sit in front of the AC condenser just behind the grill (part of the hood). They are electric, can run at two different speeds and can be operated by either a temperature sensor at the bottom of the radiator on the drivers side or by a high pressure switch in the AC system located in the liquid line just after the condenser (behind the passenger side headlamp). You can test the basic operation of this fan pair by pulling the connector to the temperature sensor on the radiator and then turning on the ignition switch. Doing so should cause both fans to run. (These fans are operated by three relays located in a relay box underneath the drivers side headlamp.) Quote Link to comment Share on other sites More sharing options...
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