Relay? Fuse problem? 355f1

Can anyone pinpoint me to where the relay is for the left side radiator fan? I know it is down behind the passenger footrest, but which one...

 

Both left and right sides are under the passenger foot rest ..... !

There is a diagram glued behind the 'metal cover/passenger foot rest' ......

 

I guess I need glasses----I didn't see it at first, didn't pull the cover far enough down to see the diagram--Thanks..

 

I was thinking that if the fan turns on with the AC switch then it should not be the relay. I believe the LH radiator thermal switch and the AC circuit utilize the same relay...... .

 

Not sure what it is....

 

Relays are also ID'd in the owner's manual and work shop manuals if you have those. But quickest is the cover/door as previously mentioned. What's the issue Robbie?

 

The left side radiator fan is not working when the temp gets up to 190. The right side kicks on with no problem. If I turn the AC on then both sides work fine. I checked the relay under the passenger footrest, I even swapped the right and left and still did not kick on. So that rules out the relay. Checked the fuse, looks perfect. Replaced the thermal switch, Ferrari #158655, still will not kick on. Goth suggested I attempt to bleed the system for any trapped air, but have no idea how to get to that bleed screw in the front of the motor without taking the engine lid off....

 

When you replaced the thermo switch, did you try shorting the two terminals together (with ignition "on") to confirm there was power to the thermo switch and the fan activated? That would at least confirm the wiring to the thermo switch it good. I suppose in the grand universe of possibilites you could have gotten a bad switch. Did you try testing the one you removed, to verify it was indeed okay?

I wonder if parking on a hill (pointed down) or jacking the rear up, would be sufficient to get the air out through the expansion tank? Just trying to save you some hassles, but doing it the proper way may be the only alternative.

 

You can get to it by removing the plastic beauty shield over the powersteering reserve and coolant expansion tank. The get a real good flashlight along with a 1/4" drive 10mm socket and a 12" extension. Shine the flashlight from under the back of the expansion tank toward the front. You will be able to see it. Then navigate your socket on top the screw. I have done it a few times standing from the back of the car. A small step stool may help here, just make sure it has some good rubber feet.... .

 

Goth also suggested the shorting technique---I will jack it back up and try that...

 

Doing the short trick turns the fan right on---It fired right up... Does this mean it is the Thermal switch? Maybe I got a bad one?

 

Maybe...... but it still seems like it could still be air in the system. Since air is not as thermally conductive as water, air in the system would not transfer enough heat to the thermal switch to allow it to activate.

Another possibility may be the thermostat is not opening up? Though bleed the system first to make sure that is ruled out.

Is the fan acting exactly as it did before you installed the new thermal switch?

 

Yes, the fan is doing the same now as it did before--so I guess that rules out the switch? The thermostat would affect both fans though wouldn't? Same with air in the system, wouldn't it affect both radiators? If you think that rules out the thermo switch, I will put it back together and try to bleed the system to rule that out also....

 

Not necessarily. The left and right radiator fans are triggered by different sources. So air in the system may not effect both sides in the same way. Left side by the thermo switch. Right side by the Motronic, which (I believe) gets it's temp signal from the thermo sensor near the oil filter housing (it has a light blue connector on it).

I would take the old thermo switch and using a candy thermometer, get some water up to 210 degrees or so, and see if you can get continuity with the switch. If so, then you know the old switch is good, and the switch is unlikely to be your problem. You could do the same with the new switch if you choose. I am with Goth, it may just be some air in there.

 

The LH radiator thermal switch activates the LH fan only. There is another thermal switch that gets its heat trigger signal from possibly the oil tank, oil cooler or by item #5 on page B16 of the manual. But Since we are talking LH here we won't get into that.

Though for certain the LH fan is triggered by the LH radiator thermal switch #8 of pg B16.

Try this..... check if the LH radiator is even getting hot on the upper portion where the thermal switch is, to verify if coolant is even circulating. If it is hot ...... then it is still possible there may be air in the system.

 

Candy thermometer? Skittles or M&M's??

 

It is getting hot just not sure how hot. After I replaced the Thermal switch yesterday, I waited a bit for the temp to get up and checked for leaks, etc. I noticed steam coming from some of the antifreeze that had spilled onto the fan and top of radiator, so the radiator was getting hot enough to produce steam on the spilled excess on the outer of the radiator...


I will button it back together and attempt to bleed the system tomorrow...

 

That is good ........ that says your thermostat is working .......... though air in the system could still be a possibility.