On my 95 E320 I have noticed something very strange. The auxillary cooling fans work sometimes, not others. Twice, when sitting in traffic, I have had to turn the heater on full blast to pull the temp. needle from the pegged position.

The strange part is that when I pull over and lift the hood, I can just barely touch the cone of each fan and they will start spinning. I have found no rhyme or reason for when this happens.

The fans spin freely with no binding. I can feel a very slight magnetic resistence when slowly turning the fans by hand.

Since this started I have replaced the engine wiring harness (for other reasons), coolant temp. sensor (4 prong, black base on the thermostat housing), and fan resistor. I checked the fuses on the fan relays and they are OK. I even took the covers off the relays and the contacts appeared ok and moved freely. Any other suggestions?

Thanks in advance.

Sounds like bad fan motors/brushes to me ...

Run a jumper from bat + over to the terminal on the resistor that has 2 wires on it and see if fans start.

I think you nailed it Arthur. I did as you instructed. I even removed the headlight fo access to the resistor from the front. Same result. I had to spin the fan to get it going. I guess I had to spin it instead of touch it since I was only using 14 guage wire. It looks like a fairly easy swap except for the pipe that runs directly in front of the fans. Is it AC or Trans.???? Will ir just move out of the way?


Thanks.

They don't come out as easy as they look

Many times when both fans need a shove , guys ask why both, not realizing that they were prolly running one one fan for a long time before they had none..

I had the same problem with one of the fans two years ago. It will occasionally not start, but than, just touching it or helping it a bit it will start spinning normally.

As bizarre as this may sound, I discovered that that fan was binding on some flaking paint that came loose at several places around the inside perimeter of its shroud. I removed the flakes and that fan has been working perfectly ever since.

Before changing the fan, look for loose paint flakes (chunks), or some other obstruction on the inside of the fan shrouds.

And Arthur is right, at least on my car, these fans are removed from the back. The radiator, AC condenser, and several other components will need to come out first.

Phil

__________________
'95 E300 Diesel, 264,000 Miles. [Sold it]

I replaced both fans and all is well. I'm glad it happened when it did because I have been driving in 100+ degree heat for the past week here in Southern California.

Thanks for everyone's input!