msmithmmx

OK OK, Fixed. I installed a Used OEM Coolant Temp Sensor and now the fan roars on when its at temp. Turning on the AC does not engage the fan nor does the clutch come on. I am calling this a seperate issue. I hate lending my tools out because I do not have my ac test guages. Thanks to all that have helped me.

Me to, I picked one up 2 weeks ago for 500. It cost me 350 to ship though. It was sold as a HG issue but the fans are not working.

Ok, how do I verify it at the ECU, all I have is a OBDII reader and a multi-meter from radio shack.

I had a very long post going before but I have decided to start over and summarize it. HELP ME The Car: I have a 97 Legacy 2.5 180K miles that is overheating when I bought it. It did have a check engine light for a speed sensor The Problem: The radiator fans will not come on. They will not turn on when the engine is at temp and it will not turn on when the AC is turned on How to force them on: I do one at a time 1) Disconnect the middle bulk head harness. This throws 3 codes a) P0117Coolant Temp Sensor P0122 TPS c) P0325 knock sensor 2) Disconnect the Coolant Temp Sensor 3) Connect the green diagnostic connecters under the dash driver side 4) Ground out the fan at the ECU What I have replaced 1) Coolant Temp Sensor 2) ECU 3) Every Relay in the engine compartment fuse box 4) Speed sensor 5) I checked every fuse in the car What I am convinced of: 1) I have a Short in the engine wire harness 2) Something is wrong with AC system Notes: I have 8 volts at the wire that connect the engine coolant temp sensor when I disconnect it from the coolant temp sensor

My knock sensor keeps tripping the "check engin light" I have now started to notice my normal 23MPG to to 18. My OBW is at 175K

Are you going to fix the HG? You looking to sell her?

I am not going to sugar coat this for you. There is a 98% chance you blew the head gasket. You will need a compression test, if that does not confirm it, then ask for a hydrocarbin test, that will be the dead give away. Do not replace the radiator before any of this is done. The fix for this job is at or around 1400. Sorry man. I have one now I am try to fix

I paid 60.00 for front and back dif

I am on the coolant temp sensor, 2 wires

I unplugged the speed sensor on the transmission, anything I should look for?

.002 was the voltage reading at the tip of coolant sensor wire with it disconnected and the key turned to ACC

Look at #2 when the car was delivered it had a check engine light for a speed sensor. I erased it but since then it was only moved a few feet into the garage. 1) Are there any other issues with the way the car is operating? When I purchased the car a week ago the guy told me it had a busted HG. I thought I would fix the fan issue first. 2) Has the "Check Engine" light come on at all during operation? Real funny you mention this, when the car came it had a check engine light with note a speed sensor malfunction. I did not mention this because I never even thought it could be an issue 3) Does the CEL light when you turn the ignition switch ON, before starting the engine? Yes the light does go solid 4) Did the CEL flash (about 3 times per second) when the green test connectors were plugged together? Yes, 3-4 times

We fixed one issue, I replaced the fan resistor, I the AC/Heater fan now works on all speeds. The fan in the engine compartment still does not come on when I turn the AC on. I even put the new sensor in boiling water.

I connected the the 2 green connectors and when I trurn the key to ACC. I hear the engine fans cycle on and spin low to to high and then repeat.

Good Lord 1) Regarding my inside fans only working at the highest level. I pulled out the resistor, its all rusted and I see where there is a broken connection inside. How much does it cost. Question, Is there a way this is causing my problem with the fans inside the engine compartment? 2) I unplugged the Coolant temp sensor. And with just the key in the ACC postion and the AC turned on I am getting .002 at the wire. 3) I have a new sensor from NAPA. without plugging the new one into the coolant pipe and just plugging into the harness I am getting the same results. Do I actually need to put it into the pipe. 4) How do I test resistance with it plugged into the coolant pipe. You guys rock.... And a pic of the little nasty bugger included

1) Where is this resistor? 2) I did confirm again when I pull just the connector off the Coolant temp sensor the fans inside the engine compartment turn right on. This is with everything else connected.

OMG, I have done this myself and I am no trained mechanic. Since the engine is out here this is what it takes Removing the flywheel to get to this stuff = 3 minutes Rear main seal replacement = 10 minutes separator cover replacement = 8 minutes

Cougar, Is there any relays inside the car that can be tested. I also found out that only the highest setting on the AC/heater controle will turn the inside fans on. The first 3 setting do nothing. I switched the whole AC/Heater controls out, no change. I am about to just sell this 97 OBW AS IS.

Nope, I had another connector off as well and I then plugged in the old coolant temp sensor. When the middle engine harness connector is off the fans turn on, I also then hear the 1st Relay click to turn the fans on. I must have a short somewhere

BREAK THROUGH --- I unplug the coolant temp sensor and when I trun the AC on the fans now turn on. Would this confirm a busted temp sensor...

What I thought was the coolant sensor was actually the engine temp sensor. Went to the dealer and they showed me the coorect part. Where is the coolant sensor

Since I have the same working OBW, 1) I switched the ECU out, no change. 2) pulled the connection off the temp sensor, I checked the voltage on the wire. I am seeing 10 volts on the wire

I was lookeing at the ECU backwards. I grounded those pins and the fans do come on. Whats Next

Your pic of the XT6 just made me look on Ebay for one. To far away though.

80 for the lug nuts