Radiator fan always-on. Previous owner called it a "mod". I need to undo it...

[EfiniX]

I guess I get the logic if you are racing the car everywhere, but the reality is that when the car sits, the temp drops below the threshold for open-loop operation (thanks to EHMotorsports for discovering this).

If I understand correctly from my reading, one of two things was done to get the fan to be on all the time when the ignition position is "run"

Option 1: The green and blue wires on the thermo sensor located at the bottom-middle of the radiator have been jumpered together (tricking the relay into think the radiator is always hot enough to trigger the fan)

Option 2: Terminals 1 and 3 on the A/C cond. fan relay connector have been jumpered together (tricking the car into thinking the A/C is on and turning on the fan as a result)

Sound about right?

 

[turbowop]

SEEMS LEGIT

Also, make sure the tstat isn't some ridiculously low temp one like 160F. Do you have ECMlink?

 

[EHmotorsports]

I put a stock temp back in.

 

[EfiniX]

I was just poking around it while on a conference call. the relay looks unmolested and the thermo wires don't look jumpered. I'll pull the actual connector off when I have a minute to see if it's jumped in the actual connector.

The other option is that it was done somewhere in the harness which.... *sigh*

 

[transparentdsm]

ok so i had this issue, some times they would stay on 100% then other times i couldn't get the fans to turn on at all. it ended up being the 6 pin plug that goes to the fans and the CTS, i couldn't source a 6 pin in time, so i got a DSM 4 pin and just connected the resistor wires together. from doing that now my fans only have one speed, high. im ok with this though and it doesn't affect anything.

 

[ghostinthevr4]

There's another way to keep the fan on when the ignition is turned on check behind the thermostat housing. Theres a single pin just like the front where the gauge temp sensor plugs into. In the back of the housing there's another single wire sensor, make sure it's connected. If that wire is grounded both fans will kick on at high speeds.

I believe it's a single blue wire it's for the A/C, it turns on both fans on high so the car won't over heat while the A/C is on.

 

[mitsuturbo]

^^^ THIS

I've experienced this firsthand. Also, make sure that the two temp switches haven't been swapped somehow. If the one from the water neck has been placed in the radiator... it will work opposite of how it should, IIRC. I think the one in the water neck is default closed circuit, and open when it gets hot, and the one in the radiator is default open circuit and closed when it gets hot.

 

[EHmotorsports]

all sensors are in the correct place. and connected to the correct connectors.

 

[transparentdsm]

then try what i said. fiddle with the 6 pin see if anything happens.

 

[EHmotorsports]

I am not working on it He is with the fan. I was just filling in the blanks.

 

[EfiniX]

Quoting transparentdsm:
then try what i said. fiddle with the 6 pin see if anything happens.



Will do. Thanks. And yeah, EH put just dropped the new motor in, so I'm sure the wires are in the right place, at least on the surface. Who knows what's hacked up with the harness...

 

[SSGdave]

I actually have this issue.
The problem with mine is, the Fan switch on the Raiator (mine is moved to the located on the non turbo lower water pipe)
Anyway... it failed in a way to were the circuit is active, which is not a bad thing. But to correct this, the switch must be replaced on mine.

Its on the to do list once I get back from this Deployment im on.

 

[EfiniX]

@SSGDAVE

Well I would hope that I discover something like this is the case. However I'm being told by the previous owner that it was done on purpose. Of course, he seemed to think there was a button on the dash to turn the fan on and off, which there isn't....

 

[marvinmadman]

Most of us wire the rear temp sensor to an automatic power/eco switch that snaps into the original coin holder spot in the console.

 

[mitsuturbo]

We do?

This is news to me. /ubbthreads/images/graemlins/dunno.gif

 

[EfiniX]

Quoting marvinmadman:
Most of us wire the rear temp sensor to an automatic power/eco switch that snaps into the original coin holder spot in the console.



Is there a FAQ on this? It's clearly not the mod I've got, but if what the PO did is similar, it might get me looking in the right place.

 

[ghostinthevr4]

This is what I was talking about in my orignal post it slipped my mind about the econo power switch or just a regular switch. You stated that you checked all the wiring on the thermostat housing, check to see if someone tee'd a single blue wire on the back of the thermostat housing. If they did it will probably lead to a ground, disconnect it from the ground and the fans should turn off when not at the appropriate tempature.

 

[marvinmadman]

Most of us old timers know about this mod. There is a few wires on the back of the eco/pwr switch. Just find one set that completes a circuit when it's pushed down. Connect that wire to the single pin on the back k of the housing and the other to ground. Done

 

[EfiniX]

my car has no eco/power switch.... However, I get what you are (all) saying.

I'm going to look into this again when I get back home later this week. I should have my new IAC motor in by then, so at least i'll be working with a car that idles correctly. Thank God it didn't take my ECU with it when it died.

more updates as I dig deeper.