Bismarck

iTrader: (1)

Gentlemen,

I have a 4L80 installed in the car, 2006 Escalade (basically a tahoe with higher trim). I have two B&M coolers in series. I used one of the thermo switches in the first B&M cooler to trigger a relay to turn on the electric fans. The spec from B&M said it will turn on (close switch) at 175 degrees and off at 145deg. Well, I had the car idle, it went up to 200 and still no trigger. checked the relay and closed it, worked fine. The thermo switch is a piece of crap. I checked everything and the flow, connections everything is correct.

For now I have just shrted the switch so the fans are on all the time, but I want to do it right. So I need recommendation for a solution. I need to come up with a trigger for the fan relay. I wish there was a way I could just use the PCM to trigger the relay.

If not can anyone sugeest a thremo switch I can put in line with the tranny line that would close at a certain temperature? if its programmable or something. Any help would be great.

thanks

cablebandit

iTrader: (37)

mine did exactly the same thing. make SURE you have the connections properly flowing thru the cooler. The out from the tranny has to go on the inlet of the cooler (straight across from the thermostat.) i had them reversed and mine did what yours is. I also wrapped the stat with some insulation so air couldnt cool it off so quickly. The insulation makes it come on sooner than without. Mine comes on at about 179degrees.

Websy21

iTrader: (34)

I am surprised with 2 in series and with fans you are having this problem. I just got the biggest cooler that B&M makes and going to use it on my 4l80e. I will bypass the rad and run without a fan, the exact same way that MM did his. Works good for him, so should also for me

DeltaT

iTrader: (5)

No help on the wiring - he covered it above - but you would get more cooling out of those coolers if you run them in parallel instead of serial (out of one, into the other). They would work better if they both got the hottest oil feed instead of one getting semi-cooled oil.

Jim

Bismarck

iTrader: (1)

Thanks, I think maybe the temp sensor on the tranny is a problem. I have to check the temp with a heat sensor gun...

As for running them in parallel vs in series, can you explain this more?

DeltaT

iTrader: (5)

PM sent.

Bismarck

iTrader: (1)

Still any recommendations on the B&M thermal switch alternative would be appreciated.

jimmyblue

iTrader: (11)

You can get small thermostats, NC or NO, from most
broad-line electronics distributors. I picked up a couple
of Selco 60C ones way back when for converting the
radiator fans setup but never got around to it. I got
mine from Digi-Key but Allied, Mouser, Jameco etc. all
ought to have something. I have also seen thermostatic
controllers from Hayden but they are kind of clunky,
pressure-tube kind of setup.

Check the thermostat switch with an ohmmeter first
and see if it has two distinct states.

Then determine whether this is a hot problem, a ground
problem or a switch problem. Some setups want a
switched ground and both ends hot, does nothing;
that kind of thing. Since you can force the relay to work
I'd recheck the relay power, thermostat ground and
thermostat "output" presuming it goes hot-relay-stat-
ground. Check grounds against the hot feed so you
can distinguish solid from open, etc.

Bismarck

iTrader: (1)

The switch is fed with a hot and the output goes to a relay. Checked teh relay works fine. Have not checked the Switch resitance with an Ohmeter. I wonder if the body of the cooler needs to be grounded, but with a two wire, I doubt it. Called B&M and they said send it in and we 'll change it, yah right, what a hassle that would be....