Ok, so I have an Escort e-fan hooked up "correctly" through a relay and a thermostat switch with the probe in the upper corner of the radiator. My problem is I can't get it set to have the fan turn on at the correct temperature. I'm using the black magic thermostat switch if it matters. When I have it set to turn on at the lowest temperature, as soon as coolant starts going through the radiator it turns on and stays on until the car is turned off, so that doesn't work. After finding that out, I pulled over and very very slowly and carefully turned the dial until the thermostat clicked and the fan turned off to see how it'd work at that position. When doing that, the fan doesn't turn on until the stock gauge is at half way and my autometer water temperature gauge (measured at the block via the coolant drain plug) reads about 190-195 degrees. Sometimes it climbs even higher and the stock gauge reads a little above half, at this point I shut the car off imediately and pull over to adjust the fan again because the autometer gauge is nearing 200.

After I was noticing this I figured I'd try to turn it down again and very very very slowly and carefully turned the dial to a lower temperature until the fan clicked on which was at half way on the stock gauge, 190-195ish on the autometer gauge. But once again, the fan never turns off after this, even when the stock gauge reaches 1/4 or less and my autometer guage reads 180 constantly. Is the thermostat REALLY that sensitive or am I doing something wrong? Is there a better place to put this? Currently it is in the upper left (by the battery, driver side engine bay) corner. The instructions say to put it into the radiator inlet so that it is measuring the coolant temperature, but wont it still be just as sensitive and stupid as it's being right now? This is really pissing me off because my fan is either on all the time once the car reaches operating temp and coolant enters the radiator, or my car gets too hot for my liking and worries me.

Any suggestions? Ask questions if something is confusing, I'll clarify.

 

Most temp switches are like that- they'll come "on" at a preset temp, but won't go "off at that temp on the way down, they're the same on aircraft, if that makes you feel any better...

My ghetto switch goes on & off manually, when needed, lol...

 

So should I just let it come on and then never turn off while I'm driving or what? I mean it seems like it's defeating the purpose of the switch to have it on all the time, I could just do that with the rely bypassing the switch completely.

 

Mine just runs all the time, doesn't seem to bother anything.

 

It should actually switch off at some temp, which will be lower than the set temp...Maybe you're not getting quite cool enough for the contacts to "break".

Try moving it, if ya want, to see if the results change...

 

I moved the probe to be lower on the radiator, about an inch lower, where there is some air flow to hopefully get it to turn off. BUT, doing this made my temps reach almost 200 on the temp gauge and starting to creep over half on the stock gauge, so I imediately pulled over, turned the car off, waited a minute, and turned it back on. Fan never turned on, so leaving it in that same position I started to turn it back a little and the fan clicked on, once again never turned itself off. What the hell is going on, I would think that will all the people that do efans that have no problem it should work better than this, but obviously it's not.

 

The hyterisis of the switch (the difference between the on and off temps) should only be 5-10deg, so I would say you have a faulty thermoswitch. I'd take it out and test it using a pot of water on the stove.

 

The black magic switch? So what, take it out, put some water in a pot and boil it, put a thermometer in there to see temps, and do what to test it? The dial doesnt have numbers on it so I don't know what temperature it is actually set to.

 

Another thing to keep in mind.. Your fans will stay on generally speaking in stop and go traffic.

Are the fans on after you drive a few blocks without stopping?

 

Can't tell since I'm in the car, only way to tell is I have a higher idle when the fan is off than when it's on. Sometimes I will have a higher idle after cruising for a few blocks without stopping, yes, so that to me indicates the fan is off. But when I have to turn it down because it's getting hotter than I like (pulling over and adjusting the switch) because it isn't calibrated in the right spot, then it always stays on and my idle is lower.

 

I'd put a manual switch in the car while dialing this in also, so that you dont have to pull over and keep messing with it when it isn't functioning properly..

 

It doesn't bother me all that much, takes 30 seconds. And for now I'm going to leave it to where it turns on once coolant starts going through the radiator I guess. Eventually I'm going to put it in the radiator inlet line for coolant like the directions suggested to, to see if that works better.

 

I have the cheap $19.99 rheostat from Advance Auto controlling my Fiero e-fan.

I cruise consistantly at 185 while driving and hit 190 in stop and go traffic. The highest I have seen my car get was on a 88F day after I redlined it in first and second. It hit 195 for about 3 min and then was back to 185 and cruising.

I have my probe attached to the water pump neck. It doesn't really matter where you attach it, as long as the coolant is running through that area because it is adjustable. I used my Autometer gauge to tell when it should turn on and off. Kept checking and adjusting until it kicked on at 190.

 

Where is your water temp gauge tapped?

 

I have seen 2 black magic thermostats fail.
One nearly cost me an overheated engine.

I put in a cheap pre-set switch probe to signal the relay - no more worries.

 

I didn't actually tap into the coolant system anyplace. My probe is externally attached to the water pump neck, right near the thermostat.

The probe doesn't have to be in the coolant to work.

 

What brand?

 

I know, but mine isn't working so wonderfully just being in the radiator. I figured I'd give it a shot being inside the flow of coolant, maybe it'll measure more accurately and quickly, I dunno.

 

This Is not the first time I have heard this...It's for this reason Is why I am constantly focused on my Water Temps.

My Black Magic #150 Incidently failed on me once before. It was covered under waranty though.

 

Yah, I'm always watching my water temp gauge, didn't know about the black magic switches being faulty though, too late now

 

I believe It was wozoom that lost his Engine due to this e-fan which first caught my attention, and this was 4yrs ago!

 

I put my sensor in the lower right, near the coolant return to the engine. Think about it, the radiator flows from top to bottom. If you have the temp probe at the top, it is always reading the higher engine temp. Not how much it is cooling. When I put my fan in I set it to come on at too high of a temp, started the engine when it was cold the watched the temp guage. When the gauge reached my normal temp I turned the thermostat until it just barely came on. Works fine for me.

One thing I did need to do was reverse the fan blade. The fan came set up as a pusher instead of a puller. Then you have to make sure you wire the hot side for the correct fan rotation.

 

The $19 one from Advnce Auto Parts.

 

Have you tried changing your thermostat to a cooler unit....maybe getting the water into the radiator before it gets to 195 would help?

Rob

 

You originaly had the thermal set too low, it was always on.

So you pulled over (mind you engine hot) and moved it too the thermalstat clicked (power off'd). To do that, you raised it higher than where the coolant currently is. Remember the engine was hot when you did this.

Now, you drove and was like... wow the fan comes on late. You went inside, ate dinner and came back two hours later when the engine has coolaned a good 40 degrees. You turned the thermalstat back down to where it clicked again, mind you-- now with cooler coolant.

Its not a piece of **** equipment (well it might not be anyhow) but more how you set it. If you set it when the engine was warm, backed it down a bit, you should be fine.