Cooling fans run constantly

[LGAFF]

So since last winter both of the cooling fans on my 90 run constantly once started. Looking at the service manual I think this has to be related to the AC system(I deleted mine) but I have pulled the pressure switch wiring, AC fuse, and changed the Temp sensor for the ECM....nothing. They dont run when the key is "on" just once started, as both fans have separated ECM "triggers" I dont think its the ECM. even tried a new relay...nothing

Any thoughts? Possible since there is no AC signal they always run since I deleted it? I didnt notice the fans running constantly before....

[secondchance]

Originally Posted by LGAFF

So since last winter both of the cooling fans on my 90 run constantly once started. Looking at the service manual I think this has to be related to the AC system(I deleted mine) but I have pulled the pressure switch wiring, AC fuse, and changed the Temp sensor for the ECM....nothing. They dont run when the key is "on" just once started, as both fans have separated ECM "triggers" I dont think its the ECM. even tried a new relay...nothing

Any thoughts? Possible since there is no AC signal they always run since I deleted it? I didnt notice the fans running constantly before....

If you mean disconnect by pulling, disconnecting high pressure switch will run fans. Low pressure closes the circuit and high pressure opens the circuit - at least for 94. Early cars are probably the same. Also, have you checked fan relays?

[LGAFF]

Yep replaced them today....not a fix...new sensor, also not a fix

[Marc Haibeck]

Hi Lee,

Unplugging the high pressure fan control switch will turn both fans on. There are two connectors that went to sensors on the high pressure line. They are near the dipstick. To prevent the fans from running the two wires on the smaller of the two connectors need to be connected together.

[LGAFF]

Thank you Mr Haibeck!