2010 Grand Caravan 3.3L Rad Fan Code

I can't recall the specific code (its on our laptop scanner at the shop) but its a code for essentially the low speed cooling fan. I briefly looked into it on Friday when it came in, but only had time for some basic checks and fan is working (altho I think its just high speed) I can use scanner to turn fan relay 1 and fan relay 2 on. I assume this is low and high speed respectively, but the fan comes on when I actuate either one of the commands (same speed level..high). I disconnected the radiator resistor connector and makes no change in how the actuations turn the fan on...get high speed when I click on relay 1 or relay 2..and with the resistor disconnected, this tells me that the resistor is not doing its job?? I measured resistance on the pins of the resistor and get 1 ohm. Went to another caravan that has same system, and it measured the same and has no codes or issues. This confused me, for I thought I had a grasp of how the system worked..low fan speed achieved thru the low fan speed relay in the TIPM which directs battery voltage thru the rad resistor to the fan motor, thus reducing its speed. High speed goes thru the high speed relay on LH side of fan housing, sending full power to fan motor.

Not having much luck getting useful schematic diagrams for these later model caravans with the repair info we have at work unfortunately. Just wondering if others who have better access to info and have worked with these vans have any suggestions on a direction to take?

More diagrams inbound! :lol:



If you're in need of more diagrams, the BBB Industries site has a pretty good selection. Side note, I'm starting to like the OE Dodge diagrams more and more :blink: Colored wires, clearly labeled pin assignments... Euro makes, take note!

The fan running during bi-directional control with the resistor disconnected is definitely weird... I'm wondering if the bi-directional control is misleading? As in, it's not controlling the relays as advertised? Just thinking out loud.

Let me know what the exact code was, and we can do some more research. My initial suspicion is that you're not going to see power at the dark blue/light green wire at the resistor, because something is wrong with the low speed relay. I'm thinking the TIPM has an output state monitor on it's low speed relay control driver, generating the code.

well seeing the low speed relay is in the tipm your going to have to find the radiator fan resistor and check for power on db/dg wire while commanding the relay on with the scanner. if you have power there that tells you the the tipm is good and the wiring is good up to the resistor. if you could find any info on what the resistor value should be you can unplug the resistor and jump the terminals with a resistor of the same value. but if this is like the pt cruisers were there is only one fan for both speeds. and those were super common to go bad. other thing is use a manufacturer flow chart for "values" of what voltage levels your supposed to see with each command. don't follow every step just use it for the values. does one of the fans come on with the ac on??

The high speed relay isn't in the TIPM?
I wonder if it's a relay as drawn or a solid state device. I'm interested to see what the code is and where that takes us.