Aux Fan -- again

[yeldogt]

I took my 88SL out of storage a few weeks ago - and even though I did not use it at all last summer the old girl fired right up.

The A/C has always been a problem on this car and as expected the A/C did not work. I had the system converted in the late 90's to 134 when the main hoses to the compressor failed - and every year it always needed a hit of 134. So I used a gauge set to fill the system and all is well - surprisingly.

But I could not get the Aux. fan to work? I have previously had work done on this and one of the fixes listed on a service from the 90's is "trace and replace inline fuse". I could not find any fuse for the fan - and I forget exactly what turns it on. I believe it is high coolant from a sensor or high pressure from the A/C ??

I remember reading that when the 134 conversion is performed the pressure? switch is changed and now actually has two functions and you must be careful to get the correct one if it ever fails. If my memory is correct it is the upper of the two sensors at the accumulator but I can not remember if it is NC or NO. Was the change to give high temp in the A/C system as well?

I looked in the posts but can not find it - I also can not find a picture of the engine compartment regarding the temp switches.

Can anyone tell me about the fuse for the system -- the two sensors at the accumulator and what the two sensors at the thermostat do on the car.

Even though it has not been real hot on the east coast this year I want to make sure this works and I do not want to jump anything incorrectly and cause more problems.

[yeldogt]

No Ideas ??

[kbdixon]

On a r129 the fused relays are beneath the fuse box don't know about a 107, a 129 has 2 relays for the aux fans 1 high speed 1 low the low is the fused one.
KD

[kbdixon]

the 129 has 6 screws holding the fuse box cover down they are visible when you remove the fuse box cover, again I don't know the 107.

[yeldogt]

From what I remember -- in the area of the thermostat -- the sensor with the single connection is the one for the fans. But I forget the operation.

I also recall that the other way the fan operated was by way of the upper sensor by the accumulator -- I believe it originally was only a pressure switch that when the pressure was too high in the A/C system the fan turned on.

I did try to jump (bridge) the pressure sensor and the fans did not work - So I am looking for the fuse and the relay location??

I also believe that the fan is only one speed - correct?