Hello everyone

We are trying to test our radiator fan motor. There are 3 wires. Red, Green and the black grounded to the body. We have a portable jumper battery. When we hook power to the red and ground the black ---no spin of the fan. Same result with green hooked to power and black grounded. There is a faint squeal--each time but the squeal sounds like the motor is telling us --you have this hooked up wrong. We would appreciate any help. Thank you very much. Bill

I copied the below from the FAQ's section on "Engine and OBD Diagnostic Codes".

You can scroll and read the whole section, but following the instructions below will test your fan hookup and lots of other things. I tried this on my '94, and it made the fan run briefly on low, then high speeds. Comforting to know the fan relay responds properly to ECU signals.


"4. Diagnostic Test Mode 3: Injection System Component Activation Test
Turn the ignition ON to KPII and install the cable into socket 2 for fuel-injection-related tests.
Press the button three times for one second each time (waiting between >1 and <3 seconds before pressing again)
The diagnostic unit then tests selected components: engine coolant fan (if equipped), fuel injectors, idle air control solenoid valve, carbon filter solenoid valve (if equipped), cold start valve, radio suppression relay and fuel pump, each of which you can hear or feel.
Exit by switching off the ignition."
--
Bob (son's 81-244GL B21F/M46, dtr's 83-244DL B23F/M46, 94-944 B230FD; grocery-getter Dodge minivan, hobbycar 77 MGB, and a few old motorcycles)

From the OEM wiring diagram:

Black is ground
Red goes to terminal C2 on the fan relay (behind the left front headlamp)
Green goes to terminal C1 on the relay

The relay is powered by a fused link from the battery which is also green to terminal A1

Terminal C2 is actuated by the ECU or the A/C high speed pressure sensor beneath the condensor
Terminal C1 is actuated by the ECU or the A/C low speed sensor

Hence, either Green or Red wires to the fan could be energized depending on the signals. The Green wire appears to be low speed; the red high speed.

steve

thanks for the help

bill