Fuse is ok. Relay is ok. Direct power to fan it works. Oil temp 210. AC doesn't work. I think I have a seal issue in the compressor and I just haven't got around to fixing it. I read that AC and right fan have a relationship. Does Ac have to be charged for right fan to work? I just changed the oil today and have let the car run to full warm up a few times. Left fan works right doesn't. Cleaned connector on fan. Checked coolant level. About one inch in bottom of tank. Where do I start with this? I have a new thermostat that I haven't installed also.
Coolant temp sensor on water manifold by oil filter. Measure resistance when cold. Should be greater than 1000s ohms. Let car warm up. Measure resistance. Should be in the 100s ohm range. $15 part at any parts store. Bosch part 0280130026.
Thank you John. Will do. Cars on the lift up top and shop was just closed for the weekend. 🤒 I'll check that first.
By the way, the water temp has to get to over 95 C (203 F) at that senosr before the RHS fan comes on.
as mentioned in previous thread. with AC compressor off (button pushed). for example, if car left at idle from cold to full warm up. the right fan will always turn on first. then the left fan will kick in as back up. the relationship with the AC is the left fan. this is why those who leave their compressor on all the time say they notice the left fan is on more then the right. or left comes on before the right. must be the thermo switch for the right fan that died which is near the oil filter.
That is not a thermal switch, but a thermal sensor. You can see that temperature reading in real time if you have an OBD2 and a scanner in real time. It will tell you what the "Computer" thinks your water temp is.
yes I had both those for left and right replaced in the past and if they go bad the associated fan will not come on.
Absolutely wrong! See workshop manual pages B79 & B71. These two radiator fans are controlled independently but, under normal operation, the LEFT fan will turn on first. The RIGHT fan should kick on when oil reaches 95*C or 203*F.
well my fans work like clock work flawless. when water temp reaches just past 90c (12 o'clock ) the right fan kicks on first for a few moments. if at a standstill, then shortly after left fan kicks on they run simultaneously until water temp is back below 90c. the only time I've heard the left fan on while right fan was not, is when I have the compressor engaged. and that is as per my 20 years experience Ferrari tech. and the left fan is indeed linked to the AC.
My right side fan was not working either, turned out to be the wiring between the connector at the fan and the fuse box. Have a look at the wiring behind the connector (loom side) might be a visual clue, and for a sure confirmation Check the resistance between the connector and the fuse box(my case it was >1kOhm, clearly a problem - should be 0). Water had got into the wire loom and corroded the cable, it was brittle and cracked. On my car, the wiring made a very sharp corner to plug into the fan, I believe this pulled the wire seals, allowing water to get in - I soldered in some wire to replace the perished section, adding a bit of length to allow a larger radius bend. If you end up doing this be sure to use the p clamps to support the cable otherwise it will soon break again.
Looks like someone used dielectric, or some other sort of grease, at least on the top photo. Can't tell if the bottom photo is melted plastic or grease and gunk. I'd start by cleaning everything up well. I mentioned above doing a resistance check, but that was for the connection between the fan and the (disconnected) relay. *Don't* do resistance checks on wires going back to the ECU (at least while the wire is still plugged into the ECU). I'd just clean those plugs up and see if that doesn't improve things. Electronics cleaner is a good way to get rid of the old grease and contaminants. Visually check the wiring behind the connector too, they often break at the wire to terminal crimp.
Coolant change, new sensor, cleaned contacts and I'm fixed. Don't really know which did it but it's coming on around 199 Thanks for the replies.
Precisely. The LH fan trigger from a thermoswitch in the LH radiator. The RH fan is controlled via the Motronic unit. It receives its signal from the thermo-sender on the rear (RHS) of the water manifold. This same sender "tells" the Motronic unit the engine temperature which assists in the fuel management maps with regards to engine temperature.
Its my understanding the RH fan is NOT controlled by oil temp. Correct me if I'm wrong but I believe its controlled by water temp at the sensor next to the oil filter. Its measuring water temperature, not oil. Am I correct?
I don't know if I needed a new sensor or not. I'm going to bench test the old one. I think I was a little low on coolant as well so not sure if that alone would have taken care of it I was doing a coolant change anyway so a good time to do the sensor. Installed the big daddy mini cats while I had the car on the lift as well. Going to clear the codes and see how that goes.
The fan unit is probably dead. I have replaced more then a few. Easy to test. Just put 12 volts directly to the fan. If it arcs heavily then she's done. If the power gets to it and still doesn't run, replace the fan. Do the easy checks first. Disconnect the fan from the harness of course before hand.
