tomellis wrote:This may be a silly question, but have you run power straight from the battery to the fan to make sure the motor is good? I didn't see anywhere in your posts that you have done this. If you haven't done that yet, it is where you need to start.
That's exactly where it should sit. I'm guessing you changed the thermostat out too? A failed-open thermostat (or an old sensor even) could have made the needle sit lower.The engine doesn't overheat sitting at idle, but the temp gauge does seem to sit a little higher, right around 3:00, where it used to sit at around 3:10 or below.
Depending on what you have as far cooling system stat, temp sensor, ect.. My fan won't come on til' 215 degrees like it's supposed to. The stat opens up round 180 degrees I believe but in summer temps w/ac on the fan goes on immediatly... yeah Volvo's are weird like that. I thought same stuff when i put the new fan in but after researching i found that everything was good.holler1 wrote:Maybe I should start a new thread, but a lot of the info in this one seems to apply. However, my problem is slightly different. A few weeks ago I had a CEL indicating a bad ECT and the ECT temp was going all over the place. I replaced the ECT and that corrected the CEL and the ECT reading on my real time monitor is in a more normal range. However, the cooling fan doesn't seem to be coming on right. The fan does run when the AC is on, but if AC is off the fan doesn't seem to run at all either on low or high speed. I ran the engine up to a temp above 210 F with AC off, and neither speed came on. When driving I have not seen any overheating, but this time of year I normally run the AC so the low speed fan is running most of the time anyway. The engine doesn't overheat sitting at idle, but the temp gauge does seem to sit a little higher, right around 3:00, where it used to sit at around 3:10 or below. You might say there is no problem, since the car is drivable, but it seems to me that at least the LS fan should come on at a lower temp than 210 F. I'm going to try driving it with AC off and see how it does- just thought of that test.
I tested the fan and relay by grounding the yellow or y/w wires on the relay, and both speeds of the fan come on, so the fan itself is OK and the relay seems to be working as it should. My question is whether the problem is likely due to bad contacts where the yellow and y/w wires go into the ECU, or where the ECT signal goes to the ECU. Hopefully it isn't the ECU itself. After reading Lee's comments in this thread, I'm going to try wiggling the wires at the ECU end and see if that helps.
I did order a new thermostat when I got the ECT sensor, but didn't change out the thermostat. The old one is maybe 3 or 4 years old and it seems to be working OK. My cooling fan used to come on after driving like yours. I suppose the new ECT sensor could have shifted the "on" point. The old sensor had gone wacky. I'm also wondering if the ECU needs to reset itself after the sensor change. I haven't been driving the Volvo that much lately, probably less than 100 miles in a week or two.jblackburn wrote:That's exactly where it should sit. I'm guessing you changed the thermostat out too? A failed-open thermostat (or an old sensor even) could have made the needle sit lower.The engine doesn't overheat sitting at idle, but the temp gauge does seem to sit a little higher, right around 3:00, where it used to sit at around 3:10 or below.
My cooling fan will usually be running as I get home after some around-town driving on 80 degree days when I'm not running the AC.
The Engine Control Module (ECM) is what is connected to the fan relay. ECM reads the high pressure sensor on high side a/c line and the ECT sensor. The ECM will run the fan at either speed as the condition warrants.holler1 wrote:Jimmy57,
Thanks. I'm going to let it run hotter and see if it comes on. I suppose from what you're saying that the low speed of the fan is only used when the AC is on?
