Fred SS

iTrader: (3)

My Monte Carlo SS has a 350 TPI motor. Running 1989 setup, ARAP bin. I recently changed my cooling fan setup to allow the ecm to control the fans. I connected the low speed fan relay to C1 of the ecm harness. My 89 shop manual says that C1 is "Cooling Fan Control". My problem is that the fans come on at about 150 degrees. I edited the bin and set the fan turn on temp to 190 degrees and the turn off temp to 180 degrees. I cannot figure out why the fan is coming on at 150 degrees. I looked through the bin and cannot see anything that could be the problem. Running ARAP bin on a F-body setup in a Monte Carlo SS. When running ARAP on an F-Body setup, your suppose to select the check box for "Cooling Fan N/O Req Input", which I did.

Any ideas?

ploegi

What temp does the ECM think the engine is when it turns on the fan?

Fred SS

iTrader: (3)

Sorry took so long to get back. Tunerpro says the coolant temp is about 120 degrees when the fan comes on. In the ARAP bin, I set it to turn on at 190.


I let the car cool down to about 100 degrees and restarted it. The fan came on as soon as the motor started.

rgarcia63

Did you connect the fans using the factory wiring, or are have you rewired to allow both fans to run together?
The ECM controls the primary fan relay with a dark green wire with a white stripe.
The auxillary fan relay is controlled by the Aux coolant fan switch and the A/C pressure switch. these 2 switches are connected with a grey wire to the ECM aux fan sense input.

Fred SS

iTrader: (3)

Thanks guys for your replies. rgarcia63, you may be on the right track. I am not using F-body fans in my swap. I'm using a late model Dodge Intrepid electric dual fan. At first I used two temp switches to control fan low speed and high speed. My low speed switch failed last month, so I connected the low speed relay to C-1 of the ECM so the ecm would control low speed. C-1 is the dark green with white stripe wire you mentioned. I'm not currently running A/C, so when I was using the temp switches to control the fans, I grounded the gray wire, D-11, which is the A/C Press Fan Switch. My research indicated that for TPI swaps, if your not running A/C, then D-11 gray wire should be connected to a common ground as is done when the car is not equipped with A/C. For now I will go back to controlling the fans with temp switches. I ordered a new temp switch today from Jegs.

Fred SS

iTrader: (3)

Well guys I had to update this thread with my latest info. This is gonna be interesting. I was going to switch back to temp switches to control the fans. But I changed my mind and decided to keep working this problem. After researching all my info for fan control, nothing seemed to make sense why they were not working right. I have allot of info on TPI swaps that I have collected over the years. Research indicated that when using ARAP bin on an F-body TPI setup you need to check the box for "Cooling Fan N/O Req Input". That is because corvette fans are controlled different than F-body. That is what I did from the start of my swap. So what the heck, let's uncheck the box and see what happens. I based this decision on the fact that I am not running a standard oem F-body fan setup. After making this change in the bin, I started her up, connected my laptop and watched the datalog. Amazingly, the fans came on at about 195 degrees and continued to run until about 175 degrees, then shut off. The same settings I put in the bin. I said no way! So I let her run for awhile at idle. Same observation, fans came on at bout 195 then off at 175. Just what I had in the bin. Now I got a brand new temp switch that I don't need. I'll put it with my collection of other new but unused/waiting to install car parts. Success, time for a beer!

Fred SS

iTrader: (3)

Thanks Thirdgen