[Colt.45]

I know this is an old subject but please bear with me. I have an alum. rad.,Black magic Extreme 185 fan, flex a lite vsc, 180 t stat, and victor Jr. water pump. When the fan comes on and runs at 60 -100% I run a smooth 190 degrees with a/c on and 100 degree temps. The prob. is it does not always do that. Is it a simple matter of breaking the hot wire with a switch for manual operation, or do I need some kind of relay or something. I really don't want to go back to my stock set up. Any help will be greatly appreciated. I'm about to have a double hissy duck fit!

[HMERacing]

http://www.sportcompactonly.com/manu...-54996-RAD.pdf
Wire up the manual switch and be done!

[nolife]

I don't understand.. What is the actual problem?
In theory...
The fan setpoint should be about 10-15 degrees higher than your mechanical thermostat. The thermostat will start to open at its setpoint and be fully open about 10 degrees higher. When it is fully open and temperature is still creeping up, eventually the fan will turn on (or speed up with a variable controller) and cool it back down. This minimizes the wear and time your fan has to run and allows full water flow through the engine and radiator. With the fan probe stuck in the rad fins, it takes a little playing around to get the right fan setpoint as that temperature there is not the same as the water in the engine. On that note.. 190F is no where near "too hot" for a car to run and there is no advantage of going out of your way and trying to keep it there. 215-220F is normal with the AC running in hot weather.

[Colt.45]

If 215-220 is normal, then maybe I don't have a problem. That would be great. I was afraid it might be a little warm for alum. heads. Unless it gets really hot out, I normally run 188- 190. In slow traffic or in town I hit 220. I'm sending the temp.reading to the controller from the coolant lines that use to go to the egr plate. If I were to go manual, would an oem light switch handle it. I have a dummy switch on my dash I could replace. Can I run a manual switch as an aux. so I could turn it on 100% in town? Thanks y'all all help is greatly appreciated.

[69fastback]

You're fan isn't on a relay? I would always put a relay in.

[Colt.45]

Originally Posted by 69fastback You're fan isn't on a relay? I would always put a relay in.

To be honest, I'm not sure. If you're talking about a fuse relay,I have a 40 amp fuse. It's a standard flex a lite fan and vsc. I just heard someone say something about it one time. So I was just trying to get straight in my head. I've done a lot of industrial elec.work, but very little control or dc work.

[Colt.45]

Originally Posted by nolife I don't understand.. What is the actual problem? In theory... The fan setpoint should be about 10-15 degrees higher than your mechanical thermostat. The thermostat will start to open at its setpoint and be fully open about 10 degrees higher. When it is fully open and temperature is still creeping up, eventually the fan will turn on (or speed up with a variable controller) and cool it back down. This minimizes the wear and time your fan has to run and allows full water flow through the engine and radiator. With the fan probe stuck in the rad fins, it takes a little playing around to get the right fan setpoint as that temperature there is not the same as the water in the engine. On that note.. 190F is no where near "too hot" for a car to run and there is no advantage of going out of your way and trying to keep it there. 215-220F is normal with the AC running in hot weather.

The problem is the controller is not bringing the fan on when it should , consistently.. Drove 15 miles into town just now. Outside temp. is 100 degrees.All the way there @60mph with a/c on it ran 188. Got into town stopped at the atm and before I could finish my transaction I was at 220. Three blocks away I was at 240.I freaked and got about 5 shades of pissed. Parked my car and the fan was barely spinning. I watched the gauge rise to 250, then the fan finally decided to come on. When I came back out of the store it was at 160. All the way home with no a/c 188-190. After 1/2 mile of drive way @1500 rpm 1st gear,192. The fan was at about 60% then went to 100% shortly. So I think my controller is junk, or at the very least, unreliable. What do you think?

[nolife]

Okay, I see now. Where is the temp probe for the fan located? Is it shoved in the rad fins somewhere? You could have an electronic problem with the controller but my first guess is the probe is not in a place where it is getting consistent accurate temperature readings and not turning on when it should be. The fact that it only heats up when you are standing still does point to an air flow issue and not likely a stuck or sluggish thermostat. I would troubleshoot the probe before hard wiring the fan. Off the top of my head, I would say move it around and hell, maybe even hold it close to a hot header pipe for a few seconds and see if the fan speeds up. One of those cheap infrared thermometers would help you troubleshoot.

[Colt.45]

Originally Posted by nolife Okay, I see now. Where is the temp probe for the fan located? Is it shoved in the rad fins somewhere? You could have an electronic problem with the controller but my first guess is the probe is not in a place where it is getting consistent accurate temperature readings and not turning on when it should be. The fact that it only heats up when you are standing still does point to an air flow issue and not likely a stuck or sluggish thermostat. I would troubleshoot the probe before hard wiring the fan. Off the top of my head, I would say move it around and hell, maybe even hold it close to a hot header pipe for a few seconds and see if the fan speeds up. One of those cheap infrared thermometers would help you troubleshoot.

I don't have the original controller with the rad. probe, it didn't last long. I used a3/8" " T " with barb fittings in the ends and the sending unit in the center. I put this contraption in between the egr coolant lines that I have long been disconnected. I have a laser thermometer (+ - 1 degree). The temp. readings on the " T " , t-stat housing and the heads generally correspond to my temp.gauge. For summer coolant, I use distilled water and 2 bottles of RP's Purple Ice. I have the set point on my fan as low as it will go. As long as the fan comes on when it should, all's well, but it doesn't. That's why I'm thinking about a manual switch for back-up.Every part on my car has less than 15,000 miles on them. A friend of mine and I dd a complete build, bumper to bumper, tires to roof. Without cutting corners on parts. Other than this cooling thing, it' a pure blast to drive. I would not take a golden guinea for it.

[nolife]

Sounds like your rig although mechanically sound and a good idea, does not work for some reason with your specific temperature sender or the electronics for the fan. I am not familiar with the BM fan and the type of probe or signal levels it uses to manipulate the fan. I looked at the install instructions for that fan which are here. You probably need their probe for the the thing to work correctly. Maybe they sell that as a replacement part separately. Call them and find out? Either way, if your setup was wired per their instructions, it shows how to install a manual override like you want. It looks like a simple 2 wire hookup (or 3 wires if you want a lighted switch) and probably any switch with at least a 12v 1A rating would work.

[HMERacing]

You may not be able to replace the probe. If it is like an autometer water temp guage, once the line of probe is damaged the guage is trash.

[Colt.45]

The controller that came with the fan had a probe.When it came on it was 100%. The prob. with it was the rheostat got so finicky. My cousin gave me this vsc that he never used. The vsc is a Flex a lite controller, and is a much better made piece than the original.The sending unit is designed to screw into a head or something. I'm picking up true water temp. now vs. rad. temp. with the probe. As soon as get my coffee fix, I'm going to study on a manual override or maybe reinstalling my original controller. I'll probably do the manual override first and see how that works out. That way I can still have the benefits of the vsc (when it works right). If not, go manual to save the day. I really appreciate every bodies help. Thanks

[Colt.45]

Originally Posted by nolife Sounds like your rig although mechanically sound and a good idea, does not work for some reason with your specific temperature sender or the electronics for the fan. I am not familiar with the BM fan and the type of probe or signal levels it uses to manipulate the fan. I looked at the install instructions for that fan which are here. You probably need their probe for the the thing to work correctly. Maybe they sell that as a replacement part separately. Call them and find out? Either way, if your setup was wired per their instructions, it shows how to install a manual override like you want. It looks like a simple 2 wire hookup (or 3 wires if you want a lighted switch) and probably any switch with at least a 12v 1A rating would work.

The diagram shown is for the original controller. It's a single speed deal. Mine is the vsc, but that's okay.I found a diagram for it. Wiring a man. switch should be a walk in the park.

[Colt.45]

Now it's official ! The Flex A Lite Black Magic 185 Extreme elec. fan was a Royal Pain In My Ass ! My controller was not the problem, it was the fan motor. It had been getting hot and quitting, before just stopping altogether. Good news is my SSP clutch fan went back in without a hitch. Hasn't been over 190 yet. So far , so good. BAM ! Case closed.

[cleangtvert]

another BM fan bites the dust! that sucks colt.45. i doint think those high dollar fans are worth a crap on a daily driver. over the years and many differant forums for differant rides ive had. i've seen dozens of posts about $300 e-fans that failed. i got lucky finding two mark 8 fans. i have one extra if i ever need it.

[Colt.45]

Originally Posted by cleangtvert another BM fan bites the dust! that sucks colt.45. i doint think those high dollar fans are worth a crap on a daily driver. over the years and many differant forums for differant rides ive had. i've seen dozens of posts about $300 e-fans that failed. i got lucky finding two mark 8 fans. i have one extra if i ever need it.

I think you are right. When it worked like it should, everything was honkey dory. But seemed like it's been a hassle of one thing or another. They warranty their motors for one yr. , mine lasted two. But less than 15,000 miles. I may start looking a mark 8 fan in case I get ticked with my current set up. No more BM for me.