Fan Problem again

[Dark Daytona]

I've got a '89 shadow N/A My problem is the fan doesn't comw like it should. It kicks in with the A?C turned on and when you have the defroster on with the blower speed switch on but it will not kick on with everything turned off. I can ride with the blower switch on and it will not go past the middle of the gauge but with it off it soars almost to the "H" Any ideas? Thanks!

[minimopar]

Check your codes and look for a code 35:

http://minimopar.knizefamily.net/fault/index.html

[minimopar]

Oops...trigger happy...

If the fan comes on, then the relay sounds like it is working. The relay control changed over the years. Earlier models have two inputs and pair of diodes inside. Later the computer controlled it directly in both the temp and A/C cases. What happens when you disconnect the coolant temperature sensor while the engine is running? The fan should come on.

[Dark Daytona]

Quote:

Originally Posted by minimopar Oops...trigger happy... If the fan comes on, then the relay sounds like it is working. The relay control changed over the years. Earlier models have two inputs and pair of diodes inside. Later the computer controlled it directly in both the temp and A/C cases. What happens when you disconnect the coolant temperature sensor while the engine is running? The fan should come on.

The fan does come on. the relay is working also. It just doesn't come on with everything turned off. Could it be a bad blower switch, maybe?

[minimopar]

I am confused about which fan you are referring to. We are talking about the radiator fan, correct? The blower switch should not effect the radiator fan except when you have the A/C or defrost on.

So the fan came on when you disconnected the coolant temp sensor?

[Dark Daytona]

Quote:

Originally Posted by minimopar I am confused about which fan you are referring to. We are talking about the radiator fan, correct? The blower switch should not effect the radiator fan except when you have the A/C or defrost on. So the fan came on when you disconnected the coolant temp sensor?

Yes it did come on when I disconnected the coolant temp switch. Wit the blower switch on it kicks on with a/c or defrost, it does not come on when the temp gauge reaches operating temps. normal driving= temp gauge goes hot fan not coming on, blower on a/c or defrost on temp gauge stays right under middle of gauge cause the fan is coming on

[HotRodDodge]

Sounds like a bad CTS to me.

[elmocarman]

What is a CTS

[jdawg]

charge temp sensor, that shouldnt have anything to do with it. That sensor tells the computer how hot or cold the air is in the intake.

[HotRodDodge]

Quote:

Originally Posted by jdawg charge temp sensor, that shouldnt have anything to do with it. That sensor tells the computer how hot or cold the air is in the intake.

Close but its a coolant temp sensor.

[minimopar]

Agreed. Pulling the sensor wire makes it go into limp-in. Sounds like the sensor is not out of spec enough to trip the limp-in mode and turn on the fan, but it is giving false readings. It may be hurting your fuel mileage too.

I had this happen to me once. Both the coolant and charge temp sensors were out of whack in a similar way and the car would flood at startup in certain temperature ranges and had bad mileage. After changing both sensors, everything was fine.

[Dark Daytona]

All of the sensors are brand new. Tried that first. Drove the car around tonight with the defrost on and the blower on the second notch and the car ran fine. Turned blower and defrost off and the gauge went up.

[minimopar]

How long did it take to go up? In this weather, as long as you are moving, the fan shouldn't even be needed...