Even though this wiring diagram says it is for 93 and later, I think it will work for your car for the aux fan circuits. ------------- Max Charleston SC
On Sat, Mar 14, 2020 at 5:24 PM Meade Dillon <dillonm...@gmail.com> wrote: > There are two relays: K9, which operates the high speed function of the > aux fans, and K10 which is for the low speed function (low speed circuit > goes through a big resistor to drop the voltage). K9 is in position C in > the fuse box, K10 is position B in the fuse box. > > High speed circuit: Test by jumping the temperature sensor/switch at the > top front of head, makes both fans run in high speed, I think you've > confirmed that this works. > > This information is for an '87 diesel, and also works for a '93 diesel, so > I think it will cover your '91 diesel. > > Low speed circuit: Signaling side of the relay: Fuse 7 to K10 pin 4. K10 > pin 5 goes to S32 (refrigerant pressure switch) which goes to ground. > Powering side of the relay: K10 pin 3 is power from Fuse D. K10 pin 1 goes > to the resister (located by the ABS pump and the reciever/dryer, behind the > left front headlight), then to the fans. > > > Test for power from Fuse 7 to K10 pin 4 with key on. Test for power from > Fuse D to K10 pin 3 with key on. Test if the resistor is open or 0.2 ohms > (correct value is 0.2 ohms). Test that K10 pin 5 has continuity to one of > the connections as the S32 pressure switch, and test that the other > connector has continuity to ground. Test that there is continuity from the > resistor to the motors. > > Order a new t-stat, so that after you get all that straightened out and > the car is still running too hot, you can fix the real problem (I predict) > which is a bad t-stat. > ------------- > Max > Charleston SC > > > > >>
2483500.pdf
Description: Adobe PDF document
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