Engine cooling fan control questions??
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Engine cooling fan control questions??
Working on malfunctioning AC in my 96 960 and found that the cooling fan does not appear to be coming on even when max AC is engaged. Hot wired fan and the control relay and they appear to be working as intended. Both speeds work when grounding the either the 1 or 2 control circuits at the relay. Restated I can unhook the connector that leads back to the computer with the gn-or and the y/bn wires. I then use a jumper to ground either one of those terminals at the relay and the fan comes on as it should.
What's weird to me is I took a digital volt meter before realizing the relay is ground actuated and checked for voltage at the pigtail. One circuit is showing 2 volts and the other is showing 6 volts. I don't understand this. According the diagram these run directly to port 7 and 22 on the ECM which it grounds to actuate the fan motor. Why would I get voltage there??
Also, If someone (I don't) had access to a Volvo diagnostic tool could they command the ECM to turn on the fan to confirm the circuit is good?
What's weird to me is I took a digital volt meter before realizing the relay is ground actuated and checked for voltage at the pigtail. One circuit is showing 2 volts and the other is showing 6 volts. I don't understand this. According the diagram these run directly to port 7 and 22 on the ECM which it grounds to actuate the fan motor. Why would I get voltage there??
Also, If someone (I don't) had access to a Volvo diagnostic tool could they command the ECM to turn on the fan to confirm the circuit is good?
Last edited by red7218; 05-03-2012 at 01:06 PM.
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