1983 300 sd running hot cause a/c

[blueranger]

1983 300 sd running hot cause a/c electric fan not turning on...

where is the little sensor for this located... anyone know...

[jbaj007]

In the 83, the only sensor is on the receiver/drier. Turns on aux. fan when a certain high side pressure is reached.

[blueranger]

so can i put a wire across it and dummy it out and get the fan to come on..

what do you think...

[jbaj007]

If you jumper the leads to the switch it will do exactly what you described.

[brandlj]

There must be a reason it is overheating. Just jumping the auxiliary fan to come on at all times is not the answer nor the cure. Find out what is really causing the overheating before you toast the motor for good. Check thermostat,fan clutch, plugged radiator etc...

Good Luck
John

[blueranger]

its over heating because that electric fan does not come on when
the ac is on.... and in stop and go traffic the main fan is rather slow..

if my fan clutch was bad would my fan be spinning on the engine.

[brandlj]

How many blades does your main engine fan have? I think Mercedes changed from a 6 bladed fan to a 9 bladed fan to help with cooling on these motors. I do not know what year that happened though. Your fan clutch should lock or engage when the engine reaches a certain temp. It is usually written on the clutch itself. You can actually hear when the clutch is engaged because your main engine fan will take on a different sound as it engages.
When you engine is cool, you can easily spin the blades of the fan because it is basically free-wheeling. Turn on the car when the motor is cool and let it idle. Take a rolled up newspaper and place it into the fan. You should be able to actually stop the fan. When the engine is at operating temp and you try to do this, you will not be able to do this because the clutch has engaged and the fan is locked to the clutch . Be very careful doing this, you do not want to lose a finger or a hand.

As for the aux fan, it comes on with the A/C when the pressure switch in your drier reaches a certain pressure, not sure what pressure it is with your car. But there is also a fuse for this fan, make sure it is not blown. Does the fan come on when you jumper the fan? Perhaps the fan motor itself is burned out.

Good Luck
John

[blueranger]

i went out and jumpered across the wires to the relay on the ac dryer
and the electric fan did not come on... i had the car switch off but i would assume this does not matter...


so i am guessing my electric fan is bad...

[RAYMOND485]

1884 300d Turbo
Turn On The Ign Switch The Fan Will Run When The Two Wires Are
Jump Or The Gas In A/c Is Hot, Can Be Replace Diy Just A Temp Probe
In The Rec Dryer 5 Min Done