Flexalite VSC solution

jjorgensen52

NHSTE - I'm the only one!
So, I installed a flexalite VSC controller in my truck. I have not had any problems with tach flutter, etc that some of the other members mentioned. However, I did have trouble with the stupid radiator probe. It didn't turn the fan on before my truck boiled over at about 245 degrees :rant: ... so, today I pulled that and junked it. Instead, I used a regular GM coolant temp sensor (the ECM style with 2 pins) to trigger that fan, installed in the water neck (I had to replace that, the old one cracked :roll: and the new one has a sensor bung in it). Runs the fan at about 175 right now, haven't adjusted it yet, but works nicely. Thought I'd mention it since flexalite said it couldn't be done :tup:
 

MikeRenz

not stock
Re: Flexalite VSC solution

i had a temp sensor fail on me for my elec fans too...and cuase my temp to go way high while sitting still. sucked. I think you should have failsafe manual rocker switches in the cab also for when the stupid things fail.

(my rad hoses didn't burst though) :lol:
 

jjorgensen52

NHSTE - I'm the only one!
Re: Flexalite VSC solution

MikeRenz said:
i had a temp sensor fail on me for my elec fans too...and cuase my temp to got way high while siting still. sucked. I think you should have failsafe manual rocker switches in the cab also for when the stupid things fail.

(my rad hoses didn't burst though) :lol:
I am most likely going to be adding a rocker for override ... I have an extra wire routed through the firewall to the console, would be easy enough to do ... have to run the LM-1 and my boost gauge through tomorrow so I might just do that
 

mattw

Active member
Re: Flexalite VSC solution

So did you tie the GM style sensor into the VSC controller? I had an older(non variable) flex-a-lite controller and it had a copper bulb that had a small copper tube that went back inside of the controller.. You were supposed to slide thing inside the upper rad hose, tighten it back up, and hope it doesn't leak.. Really stupid design... Is the VSC controller similar? If so please provide more detail into how you interfaced a GM sensor with it..


Thanks,
-Matt
 

jjorgensen52

NHSTE - I'm the only one!
Re: Flexalite VSC solution

mattw said:
So did you tie the GM style sensor into the VSC controller? I had an older(non variable) flex-a-lite controller and it had a copper bulb that had a small copper tube that went back inside of the controller.. You were supposed to slide thing inside the upper rad hose, tighten it back up, and hope it doesn't leak.. Really stupid design... Is the VSC controller similar? If so please provide more detail into how you interfaced a GM sensor with it..


Thanks,
-Matt
I will take a few pictures today and update the wiring the thing came with. The controller is all electronic and is adjustable. I like it most for the fact that it can run the fans at anywhere between 60 and 100% power, as well as run them for 30 seconds after the truck shuts down. That one I like especially
 

jjorgensen52

NHSTE - I'm the only one!
Re: Flexalite VSC solution

MikeRenz said:
and how much did this setup cost
Total breakdown
Volvo fan - Ebay, $40 , tossed the recall controller
Mounting kit - $75 from SonomaGTLover here on the boards
Flexalite VSC - $78.95 from Summit (PN FLX-31165 )
GM two pin Coolant Temp.sen. with plug - $20 from Napa

So, the controller setup cost $98.95, plus the fan and mounting kit. Probably could have figured out something to mount it with using the stock shroud to save a few bucks, but I was being lazy :lol:
 

QUICK STORM

B.A.M.F. BMW Tech
Re: Flexalite VSC solution

i'm interested in how you wired up your e-fan with the controller and sensor, please send me some info or post it, thanks
 

jjorgensen52

NHSTE - I'm the only one!
Re: Flexalite VSC solution

I did it as follows in the two different diagrams ... pretty simple hook up, just pull the flexalite probe and plug the GM one in there instead. After some testing, I've found that the GM sensor's resistance is a tad bit low (hits a maximum of about 200 or so, the flexalite's was closer to 400, but that allowed for the turn on temp to be as high as 185), my max turn on temp is now 155 degrees. As a result, I'm going to add a 100 or 150 ohm resistor to the sensor circuit and see where that gets me, probably up to about 170 degrees turn on which is my goal. I will post a more definitive idea when I figure out exactly how much resistance I need to add. So, factor in 2 bucks and some shrink wrap to add the resistor :lol:
IMG_0761-2.jpg

IMG_0760-2.jpg

Fan all wired with controller mounted
IMG_0757.jpg


probe location in water neck
IMG_0756.jpg
 

George Blake

DONATING MEMBER
Re: Flexalite VSC solution

I ended up pulling the controller out of mine. First the probe was no good. Waited a week on the other probe. Then the probe wouldn't activate the fan until boil over no matter where it was placed nor how the controller was adjusted. Set it to run 100% all the time. Lasted 5 months. Hottest day of the year, the controller quit grounding the circuit like it was supposed to. Luckily no damage was done. Had to run the heater full blast to keep temps down. Fuse housing melted(fuse was ok)but still had 12 volts to the unit, and the contacts were all loose in the housing. The thing just isn't meant for the long haul I'm afraid. Mine now runs full time with ignition thanks to a 75 amp Freightliner accessory relay. $45 for the relay. No more worries. HD terminals work just like outlets in home wiring and it's very compact.
I'm running the Ramcharger type fan setup for comparison.
Definitely have some kind of backup because the controller will most likely fail.

When I spoke with Flex-a-lite, I was assured I had the new fuse holder. Check this link. The fuse holder I had that melted is sure enough the one that was supposed to be replaced.
http://www.flex-a-lite.com/auto/html/fuse_holder_warning.html

Avoid the nonsense altogether and just put a relay in there. Eventually I plan to use the ecm to control the relay so I can get adjustable results.
 

jjorgensen52

NHSTE - I'm the only one!
Re: Flexalite VSC solution

George Blake. Fuse housing melted(fuse was ok)but still had 12 volts to the unit said:
True to form, I melted the fuse housing today... and the fuse too... killed the fan, I didn't get an accurate engine temp but the oil hit 208 before I was able to get it to start coming down... stuck in traffic of course. Popped the hood and got on the highway with the heater on (blower doesn't work, need to be moving pretty fast to get any airflow) and it cooled off to the 190's. Replaced the fuse and limped it home. Then I decided I didn't want to deal with that again and did this:
IMG_0772.jpg


Rewired the fan power feed through what used to be the air suspension circuit. 30 amp circuit, fused in the cab and constant 12v feed. Seems to work pretty nicely :tup:
 
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