BenzWorld Junior Member
Date registered: Nov 2008
Vehicle: 1988 260E
Location: Palm Beach, FL
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High pressure switch on A/C drier (probably red with 6" pigtails) controls low aux fan. Since you know hi fan works, you've verified fan motor, fuse and relay are OK. Jump the switch pigtails to test for low fan. If no, it's either the series resistor (R15) behind driver side headlamp or the resistor relay (K10) or the wiring. Bring jumper from battery + to one-wire side of resistor. That should get you low fan. If not, the resistor is bad or the wire connection at the resistor is bad. Low refrigerant level should be checked first though, b/c that will keep the low aux fan from engaging.
1988 260E (Anthracite Grey over Palomino)
Owned since new; still strong and smooth @ 197K
Last edited by Cal Learner; 08-13-2009 at 04:54 AM.