hi all 1986 2.3 16v no cooling fan have checked fuse ok i have 3 sensors on the thermostat housing which one (if any ) controls the fan. before i put power.through the one on the right appears? to be the heater gauge. the one in the middle has 2 wires.( me thinks ) one in for low temp . one out for high temp. one on the left(no idea) oh it is non air con.(as i live in england/??)car was on the ramps yesterday having laser tracking and it went to 120 degrees (ouch) regards ken

Have you checked the fan itself by applying 12 volts directly to it?
Is there a separate fan relay? I have one on my 123. When my fan went flakey I merely jumpered it so it runs when the key is turned on. Other owners wire their aux fans into the a/c compressor clutch circuit so it comes onb when the a/c kicks in.
There may two switches on your receiver-dryer. One with a pigtail (on the 123) controls the fan. If the fan starts when you jump those connections, look into the a/c system. Some mechanics replace the pressure-operated fan switch with a temperature operated switch.
But jumpering is a small sacrifice to avoid an overheating problem. On a long trip it has saved me much grief.
If your model has a Kilma board, see other posts on this site for specific Klima suggestions.

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thanks for the reply but you missed the point my merc has no air con. i would like to know which of the 3 outputs is the aux controller before i start putting 12 volts through them