I have asked this question several times over the last year or so and no one responds at all. So I was hoping Icemark, that your extensive background could help me(or anyone else).

From previous searches I have confirmed that the Cooling Fan warning light is designed to come on when there is a problem with the efan. But on my 1987 t2 (less then 50K milesand no mods) the light comes on every time the efan turns on. So since the efan always comes on when the A/C compressor cycles my fan warning light goes on and off. Now the fan works and I have no cooling problems, just a cooling fan warning light that is now an A/C compressor duty cycle indicator. The light does not come on if I don't turn the A/C on.

Has anyone heard of this before? Can anyone help me?

 

Well that warning light indecates if the fan has an open, short, maybe even high resitance.. That fan only comes on for AC condinser.. not for engine cooling system. The fan might still work, but might be gunked up with stuff causing a high current load causing the light to come on. Inspect the fan for resistance, short or if it spins freely..

This is just my understanding.. so don't quote me on it.. but would be a good start to inspect the fan.

Might want to change the title to reflect the topic.. and I don't believe you can post usernames in the title.

 

Well thanks, at least I have a direction to go in.

I know I am not supposed to use names in the subject, but I have posted this same message several times over the past year and You have been the first positive response. Not even the guys, like Icemark, that know this system backward and forward. It makes me wonder if I am on a blacklist somewhere.

 

No user names in thread titles, if you want his help specifically PM him, thanks.

 

That fan should come on anytime the water temp is over 207 degrees OR the air conditioning switch is placed to ON.

Some cars without a/c have the fan and in that case the fan should come on when the water temp is over 207 degrees. I've seen and observed this on a car that was idling with no radiator fan shroud installed and the hood off. That plucky little fan would come on when the temp was over 207 and sure enough it had enough guts to make the temp go down and turn itself off.

See the 88fsm manual that is online for a schematic of the fan on page 3-5 of the cooling section

 

What the deal is, is that when you lose a ground to the fan circuit you cause the fan to come on. The a/c switch does this by pulling in a relay that in turn removes the ground from the circuit and in the case of the water temp switch on the filler housing, it has a ground from it going to the fan circuit but once it sees 207 degrees, that ground is removed from the circuit. See that 88fsm and the pages I recommended and you'll see what I mean by the above words. Gone

 

..

 

,,Does the fan come on if the a/c is off and the key is just to ON (engine not running)?

If the key is to ON, and you pull the connector off the water temp switch, does the fan come on? Water temp sw being the one on the water filler housing.

 

**********What the deal is, is that when you lose a ground to the fan circuit you cause the fan to come on. ************

Just disregard that post. It's a wrong statement. I was just seeing if Wayne was paying attention.

 

Damn, I missed that...Then again, I don't have this setup on my car (or the schematics, for that matter), so I forgive myself. I should have known something was wrong, because you posted more than once