2 sets of plugs for efan and coolant temp sensor?

[watchamakalit]

Back history first.

88XJ auto engine harness swap.

Never had any cooling issues since I bought it.

I have never seen the electric fan come on. 

This started with an O2 sensor change to replace a non responsive factory unit.

After r&r of the exhaust manifold to repair a buggered up thread for the O2 sensor, I come across this tucked away in the corner. Which set is the fan and coolant temp sensor and what are the others?  One set comes from the large loom the other from the small. Also any ideas on what the red wire wired to the red with black trace in the small harness would be about?

[watchamakalit]

Well I don't know if I hooked up the correct set but the rem unit is reading water temp. I am assuming (yes I know what that means) I got the right ones. Any way to test the fan other than wait for it to get warm?

[Pete M]

the fan doesn't kick on until the engine is practically overheating (like 230*).  I think it comes on with the AC though if you have that.

[schardein]

1 hour ago, Pete M said:

the fan doesn't kick on until the engine is practically overheating (like 230*).  I think it comes on with the AC though if you have that.

Yep, on my 91 the e-fan kicks on immediately with the AC.

[Salvagedcircuit]

Curious, on renix years, when does the electric fan come on with the AC? I was testing my AC this weekend, and while my compressor clutch kicked on once (squealed loudly), the fan never came on. I tested the fan separately and it runs fine with a 12v 10a psu.

[87MJTIM]

12 minutes ago, Salvagedcircuit said:

Curious, on renix years, when does the electric fan come on with the AC? I was testing my AC this weekend, and while my compressor clutch kicked on once (squealed loudly), the fan never came on. I tested the fan separately and it runs fine with a 12v 10a psu.

 

The efan turns on automatically when AC is turned on.

 

My efan comes on when the REM registers coolant temp of 219*.  The efan temp switch is on the cool side of the radiator.  The efan switch is supposed to come on at 195*.

[Salvagedcircuit]

2 minutes ago, 87MJTIM said:

 

The efan turns on automatically when AC is turned on.

 

My efan comes on when the REM registers coolant temp of 219*.  The efan temp switch is on the cool side of the radiator.  The efan switch is supposed to come on at 195*.

Thanks for the info. Does anyone know if the temperature switch has the same connector as the fan? Maybe my connectors are swapped around. Or my temperature switch needs a replacement.

Thanks!

[87MJTIM]

 

Efan wiring diagram

[87MJTIM]

Connectors C243 and C244

[Salvagedcircuit]

I know what I'm testing this afternoon. Thanks a ton @87MJTIM!

 

[pizzaman09]

My 90 Renix truck turns in the e fan with the AC.  I recently put a new thermostatic switch in, in the radiator as opposed to the original lower radiator hose, and it seems to kick on the e fan north of 206F according to the REM.

[91Pioneer]

5 hours ago, pizzaman09 said:

My 90 Renix truck turns in the e fan with the AC.  I recently put a new thermostatic switch in, in the radiator as opposed to the original lower radiator hose, and it seems to kick on the e fan north of 206F according to the REM.

The e-fan needs to come on with the A/C, that fan is for A/C operation (condenser) it's not for engine cooling at that point. Does it still come on with the A/C now that you made the change?

[pizzaman09]

4 minutes ago, 91Pioneer said:

You should put that back the way it was. The e-fan comes on with the A/C for the condenser to operate like it's designed, it's not for the engine cooling at that point. The A/C operation doesn't care what the engine temp is.

I haven't changed any of the wiring from the factory, just put the switch in the radiator where it probably was supposed to go.

[watchamakalit]

So even though my ac has no charge and doesn't do ac things, the fan should still operate when the dash selector indicates a need for air?  I know the fan itself is good and works when jumped with power.

[91Pioneer]

2 minutes ago, watchamakalit said:

So even though my ac has no charge and doesn't do ac things, the fan should still operate when the dash selector indicates a need for air?  I know the fan itself is good and works when jumped with power.

There are sensors in the A/C system so I think if the A/C compressor isn't running then there's no need for the e-fan to run... I can't say 100% because my A/C works.

[Ωhm]

On 8/4/2023 at 5:26 AM, watchamakalit said:

Well I don't know if I hooked up the correct set but the rem unit is reading water temp. I am assuming (yes I know what that means) I got the right ones.

 

The REM uses the block sensor for coolant temperature. Engine Coolant Temperature (ECT).

 

 

41 minutes ago, watchamakalit said:

So even though my ac has no charge and doesn't do ac things, the fan should still operate when the dash selector indicates a need for air?

No. AC needs to be fully functional otherwise ECU will not pick AC Clutch Relay which also feeds Cooling Fan Relay.

 

 

EDIT: Do not test

[watchamakalit]

1 minute ago, Ωhm said:

 

The REM uses the block sensor for coolant temperature. Engine Coolant Temperature (ECT).

 

 

No. AC needs to be fully functional otherwise ECU will not pick AC Clutch Relay which also feeds Cooling Fan Relay.

 

 

Try this:

Using a fused jumper wire, jump D1_5 to D2_6. Both AC Clutch and Cooling Fan should hit.

 

 

I should have just messaged you to begin with. Lol.

 

Any clue as to what the other set of plugs would be?

[Ωhm]

Don't do that test yet. You must remove the AC Clulch Relay first.

[Ωhm]

4 minutes ago, watchamakalit said:

Any clue as to what the other set of plugs would be?

 

My guess would be LOW/HIGH speed fans. Maybe something for a winch.

[watchamakalit]

Key on or off for the test?  After ac clutch relay removal jumper the same posts?

[Ωhm]

2 minutes ago, watchamakalit said:

Key on or off for the test?

D1_5 is HOT AT ALL TIMES. Key position will not matter.

 

2 minutes ago, watchamakalit said:

After ac clutch relay removal jumper the same posts?

Yes.

[Salvagedcircuit]

Does anyone have the part number for the Thermal Fan Switch for the electric fan? Is it Standard Motor Products TS258?

 

This is the switch found on the lower drivers side of the radiator. There is a bung hole (about an inch in diameter) with a thermal switch in it. It has a two wire connector. Thanks.

 

 

[watchamakalit]

On 8/5/2023 at 12:30 PM, Ωhm said:

D1_5 is HOT AT ALL TIMES. Key position will not matter.

 

Yes.

After pulling the relay and testing jumping the terminals does nothing. I even confirmed to make sure I had power at d1-5.

 

Edit: tested with both sets of plugs neither of which made any difference

[cruiser54]

Gimme the wire color codes for each connector plz.