does any one know what triggers the rh fan relay,
RH fan relay is triggered by the engine ECU according to the coolant temperature measured by the NTC sensor. cf user manual : Image Unavailable, Please Login
I thought the right fan was sort of a back-up. Mine left fan comes on almost as soon as I start the car - and sounds like a Hoover vacuum cleaner. The temp stays put in the happy center, but is this normal?
Fan operations have already been discussed (try a search) but as a summary: - the LH fan is triggered by a thermoswitch located on the LH radiator AND by the A/C system according to the pressure. - the RH fan is triggered by the Motronic according to the coolant temperature measured by the NTC sensor located in the center of the V (coolant at the output of heads). In your case, try to switch off the A/C. If the LH fan runs as soon as you start the car, you probably have a thermoswitch stuck in the closed position.
Before you go for sensors etc check the fuses..2 fuses ..1 for each fan. The fuses DO go out a lot. Pete
Agreed. I don't know about "a lot", but I had the left had one go out once. Replaced it a year ago, no further problems. Someone said if you drive in the rain (common here in Seattle) the resistance of all that water at freeway speeds (through the fan blade/motor) can cause a lot of current draw on the circuit, causing the fuse to blow. I even saw a friends 355 that had 40 amp fuses (stock is 30 amp) in the fuse panel installed sometime prior to his purchase....obviously someone got tired of replacing fuses! I think I would be inclined to purchase 30 amp circuit breakers from AutoZone if they blew that often. They are only $4.99 and automatically reset, so you don't have to dig around in there each time to check/replace. Similar to these: http://www.wiringproducts.com/dept_28.html But the ones at Autozone did not look as tall, and the added height of the ones pictured in this link might be a problem.
