SPF Cooling Fan Issue

dblvenom · #1 (**permalink**) 06-13-2008, 06:43 PM

I have an SPF MKIII about a year old. I am experiencing a problem with the my radiator cooling fans.Specifically, the fans are not automatically engaging. I thought the problem was with the thermo switch that taps into the radiator so I replaced it. Unfortunately, it did not solve the problem. The fans work if I use my manual dash switch. Has anyone had a similar experience and if so can they share their insight on a fix?
Thanks

Rick Parker · #2 (**permalink**) 06-13-2008, 07:11 PM

Check the relays

McDoo · #3 (**permalink**) 06-13-2008, 07:22 PM

The thermo switch acts as an an open until the temperature hits the desired result and then it acts as a short to ground tripping the relays. Sounds like your the radiator is isolated from chassis ground. Pull the wire off the thermo switch and connect directly to ground and if the fans come on that's your problem......

McDoo

STEVE-O · #4 (**permalink**) 06-13-2008, 08:00 PM

Quote:

Originally Posted by dblvenom

I have an SPF MKIII about a year old. I am experiencing a problem with the my radiator cooling fans.Specifically, the fans are not automatically engaging. I thought the problem was with the thermo switch that taps into the radiator so I replaced it. Unfortunately, it did not solve the problem. The fans work if I use my manual dash switch. Has anyone had a similar experience and if so can they share their insight on a fix?
Thanks

How did you test the fans? Mine come on once the temp guage reaches ~95.
When they are on ( either automatically or manually) is the ammeter almost to the minus extreme? Didnt think the fans had that much of a current draw and wanted to check.

Blas · #5 (**permalink**) 06-13-2008, 08:21 PM

Steve-o.
As mentioned below, just connect the two wires on the radiator fan switch (lower left hand corner) that should start the fans spinning. If not, keep them connected and add a new ground wire to them. Still not running? then it's a power issue....The fans do draw a lot of power but should not peg the AMP meter all the time. Contact me off line for further things to look at. SPF car numbers would help too.
Blas

thudmaster · #6 (**permalink**) 06-13-2008, 09:01 PM

Blas sells some great wiring diagrams for spf. They are wonderful items when trying to figure out which wire is which. I had to buy one for my avitar to put it back on the road and one for 2742 I used for the fog lamps and msd.

STEVE-O · #7 (**permalink**) 06-14-2008, 06:21 AM

Quote:

Originally Posted by Blas

Steve-o.
As mentioned below, just connect the two wires on the radiator fan switch (lower left hand corner) that should start the fans spinning. If not, keep them connected and add a new ground wire to them. Still not running? then it's a power issue....The fans do draw a lot of power but should not peg the AMP meter all the time. Contact me off line for further things to look at. SPF car numbers would help too.
Blas

Dblvenom, are you testing your fans with this technique or letting the temp rise and seeing if they turn on?

dblvenom · #8 (**permalink**) 06-14-2008, 11:32 AM

Steve-O,
I was letting the temp rise..It exceeded 105 Celsius and did not engage...Prior to the having this issue it would "kick on" at ~90C...Later today, I will pull a wire from the thermo switch and ground it to see if the fans engage. If you have any other thoughts, they would be greatly appreciated...
Thanks

carmine · #9 (**permalink**) 06-15-2008, 03:28 PM

I just experienced the exact same problem with my fan, would not come on at temp. Replaced the rad fan switch and relay and still not working. turns out my thermostat was stuck in closed position. You see if the radiator dosn,t have hot fluid running through it in order to activate the bi-metal fan switch, your fans won,t activate. Its the thermostats job to open and let hot fluid run through the rad. If it dosn,t open the rad stays cool and the engine gets hot.

dblvenom · #10 (**permalink**) 06-16-2008, 09:47 AM

Carmine,
When I manually enagae the fans from my dash toggle switch, the temperature drops down quickly. In 100+ degree heat in traffic the car would not exceed 90C with the fan on. I think a faulty thermostat would cause overheating since the water/coolant would not be able to flow. Really appreciate the feedback.. For the group, I did test the wires going to the switch by removing the two leads and having them touch. The fans kicked on leading me to believe that I have power at the switch. This is my second switch. I am wondering if maybe my temp gauge may not be accurate (out of calibration).Planning to borrow an infared temperature sensing tool to check the temperature at the sending unit. Thoughts?

carmine · #11 (**permalink**) 06-16-2008, 10:05 AM

Dblvenom, It cools down because your coolent is being circulated through the block by the water pump and your fans are sending cool air around the block thus cooling it down. Once moving at cruising speed your fans can probably be turned off and the air flow thru the cool rad and on to your engine is enough to keep your car at operating temp. In other words i experianced everything your discribing and changed and checked everything youve done and it turned out to be a faulty thermostat.

carmine · #12 (**permalink**) 06-16-2008, 08:59 PM

Hello again Dblvenom. You can check to see if the new rad swich is working by taking it out and keeping the wires connected and holding the switch with vise grips, then using a propane torch you lightly aim the flame at the sensor end and within 10-20 seconds your fans should kick on, move the torch away from the switch as soon as the fans come on so you dont over heat and damage the switch. If it takes much longer torch time than about 20 seconds chance are tha rad switch is no good. I have experianced a bum new rad switch myself.
Hope this helps
Regards Carmine.

thudmaster · #13 (**permalink**) 06-16-2008, 11:07 PM

Thats what I like to hear.......propane torches and fiberglass.......

The only time I have heard my cooling fans is when I manually flip the switch..My last spf use to engage the fans all the time.....If it got near 100 degrees they were on...I like this new way better.......

Goopie 18 · #14 (**permalink**) 06-17-2008, 06:54 AM

The fans on my SPF never went on by themselves. I have the manual switch and that's what I use. I also have a fuse/switch/relay problem. Passenger side fan blows it's fuse often. I removed fuse and just use one fan. Plenty of cooling power even in hot Florida.

Blas · #15 (**permalink**) 06-17-2008, 10:36 AM

If you are interested in trouble-shooting this fan issue, contact me off-line at the email noted below.

Madmiles442 · #16 (**permalink**) 06-18-2008, 11:05 AM

God Ed,
I really wish you would change your Avitar. It just makes me sick to my stomach every time I see it.

dblvenom · #17 (**permalink**) 06-18-2008, 03:12 PM

Update....Yesterday, I utilized an infared thermal temperature tool (great item to have handy). It turns out that my Smith water temp gauge is out of calibration. My gauge read 110 Celsius(230 F) while the actual temperature at the sending unit was 185 F (also took reading at radiator as well as the return side). It was at that point that the fans automatically engaged. In the past, the fan would engage when the gauge read 90C. Thanks for all of your input