1995 Subby legacy,,,,No rad fans. Faulty relay found and replaced. No effect. pulled plugs from fans, jumpered, both fans work jumpered. Pluged Pegisys in to OBII port ran for codes, no comm w/ ECM (Communication Error?). Ran two other options ls, and base, same results. Where is the fan/temp sender (Component location)? Pulling hair out. ECM failier? Anyone have any idea's?

there should be a coolant temperature sending unit in the radiator, that would be the one to signal the fans that it is time to turn on and cool the radiator down.

Two senders in cross-over pipe RHT side top of block from upper rad hose. One for the ECM the other for temp? Is the temp (one wire) sender "Normally open or closed")? And can you ground to test or is this meathod to risky cause of spikes to ECM?

I replied in your other thread, but don't worry about the single wire, that one only feeds the gauge in the dash. The brown connector one is the sensor you may need, this one feeds the ecu, which in turn will power the fans. As for temp sensors in the radiator, that ended with the Loyales. All the EJ motors have the temp sensors located under the intake manifold on the coolant bypass.

As for temp sensors in the radiator, that ended with the Loyales. All the EJ motors have the temp sensors located under the intake manifold on the coolant bypass.

 

LOL thanks for the info, i've been out of the net on soobs for a while. all i have now are three new styles, and i haven't had much chance to work on them yet, but getting there slowly

Hey thanks guys, as always it is always better to keep it simple. I gathered that the computer is doing the calculations as to fan on temp and fan off temp. This would be easily checked with temp gun if I had the spec's. In a little shop like this we do alittle of everythng, cant be choosy these days. But boy do I miss "someone elses" libraries and software. I take it,,the second fan is slaved in some way to the HVAC system as is the high low speed on the fans? Their wired

(2- hot / one-ground) on each harness plug. I would kill for decent schematic and spec sheet on this thing.

SubaruAlliance, no problem! And it's good you haven't needed to work on them yet

R @R&L . The two fans are interactive by the sensors and relays. My Leg had a bad wp seal and the only fan which kept it alive was the a/c fan. The reg cooling fan had a bad socket conn. It was coolish and to my knowledge wasn't calling for defrost yet that fan had defaulted. Once the conn was repaired only the reg comes on unless it's summer, a/c,etc

I have seen corrosion or pigtail damage on the bottom of the engine compartment fuse panel. If the car has been in an accident this is more probable.

I have also seen one that would come on with the A/C but not operate with the temp sensor, in this case it was the sensor itself. It also had a drivability issue on warm starts which was rather strange until I fixed it.