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Discussion Starter #21
The unit I bought is a Derale 16749. It has a threaded temp probe, 30 amp fuse, relay, wiring and the adjustable controller.

I have been reading about PWM controllers and OBD2 compatible controllers. To tell you the truth, I am just some guy trying to get the fans to work and all this is above my pay grade.

I already bought a new resistor(between the fans) and a new CHT for the car.
When I was testing, I remember the old CHT had power to one side(test light to battery ground), and when back probing the other side(test light to battery ground) , the fans came on. Like I asked earlier, do you think this could be a ground issue? Or would that indicate a faulty CHT?

I guess I should have removed the CHT, put it in a pan of water with a thermometer and a VOM on ohms to see if it was working.

I really did test the relays, and I bought a new relay for R3 but that didn't help either.
I looked beneath the relay box and found no loose wires at R3 but when removing R3, one time, I heard the fans come on and off according to how I was moving the relay to remove it. Tried to duplicate that, but it doesn't do that any more.
 

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Discussion Starter #22
"Since you say you tested the relays then you need to jumper at the BJB power terminals on the low speed (R4) and high speed (R3) relay terminals and verify that the fans operate in low and high speed."

I guess before installing that aftermarket fan system that will give me more headaches, I will do as you say and jumper the BJB.
 

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Discussion Starter #23
Yes both fans are working and jumpered from their respective relay + terminal. However, R3 + seemed losser than R4 +. I will try to repair this.. at least a small piece of foil, relay inserted, while I test the system again while watching C temp in test mode. Could be no continuity?

The jumper wire, #10 wire, kept falling over and would not stay upright.

Better yet, I will put a small bend on R3 relay + pin. Enough for firm fit.
 

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Discussion Starter #24 (Edited)
Not getting ANY power to either side of CHT. Engine running or off. Shouldn't one side be hot until the sensor reaches temp?

Bending relay + pin to make tighter fit did not make a difference.

I know there is power there. And I know the relay is good..it's new.
I also know that there is NO power getting to CHT. I will look for a schematic. Find one and the trace back the CHT hot side till I find + power. Fix that problem and continue.
 

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Discussion Starter #25
I had the leads backwards. CHT is working. And I left the engine running clear up to 112C. The low speed of fan kicked on. Waited and the high kicked in. Now at 114C and both fans turned on low.

How hot do these engines run? Is this normal? Still can't get AC fan to cook on using AC switch on the dash.
 

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I had the leads backwards. CHT is working. And I left the engine running clear up to 112C. The low speed of fan kicked on. Waited and the high kicked in. Now at 114C and both fans turned on low.

How hot do these engines run? Is this normal? Still can't get AC fan to cook on using AC switch on the dash.
(y)
Just FYI:
The CHTS is just a thermistor (variable resistance based on temp) and can not really be installed 'backwards' (ie leads reversed). Perhaps they were just not making good contact. The CHTS is connected between PCM pin 33 (VREF) and PCM pin 41 (SIGRTN).

The ways the fans are wired they always run together. They either both run in low, both in intermediate, or both in high. If only one fan is running then either one fan motor has failed or you have had a failure of one of the two intermediate speed relays (R9, R10).

Good luck
Paul
 

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Discussion Starter #27 (Edited)
You misunderstand. I had the leads of my test light backwards. CHT is - negative. I had my test light to negative on the battery. Switched to + positive and it lit up.

My Chilton manual says there is a switch called Dual Pressure Switch between PCM and CHT. Can't seem to locate it. I have found a couple switches on the AC components though.

Is 114 C normal operating temp?
 

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You misunderstand. I had the leads of my test light backwards. CHT is - negative. I had my test light to negative on the battery. Switched to + positive and it lit up.
You need to be careful when using a test 12V light on the VREF circuit which is NOT 12V.

Paul
 

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Discussion Starter #29
Oops! Didn't know about that. Worse case, I go back to the pullit yersef place and get another one.
 

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VRER (ie reference voltage) is a 5.0+/-0.1 VDC voltage created/used by the PCM for various sensor circuits. The VREF voltage regulator could be damaged by drawing current on it with a 12V test light. Never put a 12V test light on any sensor circuit without checking its source.

Paul
 

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Discussion Starter #33
I will have to get another one from the junkyard. It just seems like 114C is too hot. Not used to these newer cars. Don't know how to work on OBD2. Pretty good with the mechanical side. Just did replace thr intake with one that had tight flaps in it. Also new knock sensor, thermostat and pcv and hose while I was there. Had a 2.3 manifold off of an Escape I was going to use but it turned out broken.

Gonna park the Focus for a couple days. Work on it a bit later.
 

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Discussion Starter #34
After doing more research on Google, I have found that higher temps on these newer cars is normal. Didn't find much about Focus yet but did on 04 Corvette..235f. and Cadillac ..230f and others. my fans came on the first time at 112c or 233f so I guess, not that far off. Will install a temp gauge and watch it.
 

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Discussion Starter #35
Must be my lucky day. Fans still coming on at 114C. Not overheating either. ECU must be ok
 

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I cannot get the fans to run. Have done a lot of reading and troubleshooting but no go. Relays are working. Fuse is good. Checked for fan operation by direct to battery. The resistor was bad and only reading 0.00 ohms when tested. Replaced it. Tried turning on AC but still no go. Bought and installed new CHT and pigtail. Still not working. Did the key on, press ODO reset button thing and got a 90C which I think is 194F. The thermostat is NEW and rated at 180 F.. I am at a loss. Before replacing the CHT ,I tested it by connecting a test light to ground and probing one side. It lighted the test light. Then I tried the other side and the fans came on!!
Do you think this could be a ground issue? If so I will need a schematic.
I had a similar problem couldn't figure it out so I wired the fans directly to the relay. Now they run at start up
 

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Discussion Starter #37
My problem was being old school. Not used to these engines running at higher temps. My pickup, with mechanical fan, has a 180 thermostat in it. 230 degrees is way more than what I am used to seeing. Took a lot of reading Google.
 
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