In the past year, I’ve had two overheating problems on my 2005 Ranger 4x4 carb 500. The first time I replaced the ECM, and it fixed the problem. However, the second time, no such luck, as I replaced the ECM again and the fan is still not coming on. On both occasions, the “Hot” light never came on, but I know it’s overheating because coolant is coming out of the radiator cap, and on a couple occasions, it has gone into “lock” mode and wont restart until it cools down. Here’s what I’ve done so far to try an remedy the problem:
- Unplugged the fan at the temp sensor, and fan came on (ECM good, right?)
- Took out the temp sensor, warmed it with a heat gun, and fan came on (Temp sensor good, right?)
- When I removed the temp sensor, a lot of coolant came out the hole…enough to drain the radiator; so, I’m thinking the thermostat was open (shouldn’t it be closed when cool?)
As you can guess, my next thought is too replace the thermostat, since it appears to be open all the time, and the temp sensor is not getting hot enough to kick the fan on? However, this parts changing mechanicing is getting expensive and very time consuming, so I wanted to run ny thermostat theory by some of you before I started. Also, I looked at the service manual on replacing the thermostat, and it says: “Install the thermostat with one of the air bleed holes positioned next to the upper thermostat cover bolt hole”. Hu? “With one of the Air bleed holes”…I guess I'm suppose to replace the thermostat with an air bleed hole? Never seen one of those...
Am I off base with the thermostat? And, thoughts/suggestions would be appreciated.
Thanks in advance for your help,
Jimbo
- Unplugged the fan at the temp sensor, and fan came on (ECM good, right?)
- Took out the temp sensor, warmed it with a heat gun, and fan came on (Temp sensor good, right?)
- When I removed the temp sensor, a lot of coolant came out the hole…enough to drain the radiator; so, I’m thinking the thermostat was open (shouldn’t it be closed when cool?)
As you can guess, my next thought is too replace the thermostat, since it appears to be open all the time, and the temp sensor is not getting hot enough to kick the fan on? However, this parts changing mechanicing is getting expensive and very time consuming, so I wanted to run ny thermostat theory by some of you before I started. Also, I looked at the service manual on replacing the thermostat, and it says: “Install the thermostat with one of the air bleed holes positioned next to the upper thermostat cover bolt hole”. Hu? “With one of the Air bleed holes”…I guess I'm suppose to replace the thermostat with an air bleed hole? Never seen one of those...
Am I off base with the thermostat? And, thoughts/suggestions would be appreciated.
Thanks in advance for your help,
Jimbo
