Is there a relay that controls the electric fan on the front of the radiator? As I understand it, the fan comes on at idle only and is controlled by a relay. Where is the relay located?

I have just purchased the car, 1987 300 TD, and the PO seems to have hacked a relay into the harness near the front left of the car, and I want to put it back right.

scott lyons

i did some more searching here and found it. sorry for the slightly newbie post, but the search function here takes some getting used to :-)

i still need to figure out why the fan has been wired to stay on, but a bunch of searching has led to the conclusion that something else was broken - a/c temp switch perhaps - and the fan was rewired to compensate.

scott lyons

The fan comes on at low speed as directed by the refrigerant high pressure switch and at high speed as directed by the temp sensor on the coolant outlet where the upper radiator hose attaches. The temp sensor is notorious for failing. Next would be a bad resistor preventing the low speed mode.

Sixto
95 S420
87 300SDL

sixto,

thanks for the input. what is the test for the temp switch? where exactly do i look to find the resistor and what does it look like?

i have another thread going in the diesel forum. perhaps i should consolidate to there?

http://www.peachparts.com/shopforum/diesel-discussion/133342-87-300tdt-c-aux-fan-hack-newbie-qs-long.html#post976779

thanks,

scott lyons

Definitely consolidate posts. The folks in the Diesel forum know their stuff. Particuarly the TD which I only know by silhouette

Sixto
95 S420
87 300SDL

ok, done, this is moved to the diesel forum.

scott lyons