DB9 Radiator Cooling Fans

[AttomoZ]

Hi all! Recently my 2007 DB9 Volante's radiator fans have stopped working properly and I've gotten P0480 (Fan Control Circuit) and P0483 (Fan Performance) codes. I assume this would mean that my fan computer still functions properly and only the fans themselves require a swap. I've done some research and found that the fans are shared with Jaguar XK8s (part #: MJB4270AB), but of course all the ones out there are second hand and I am afraid they may not last if I swapped my dysfunctional fan out with a close-to-dysfunctional fan.

That being the case - my question is whether or not the radiator cooling fan in the newer models (Cooling fan part #: 8D33-8C607-AD) be interchangeable with the old one (Cooling fan part #: 4G43-8C607-AA)? Eyeballing the two fans it seems both share very similar fitting - but the former one is almost half the cost of the latter. Newer parts (does not necessarily, but usually...) means better performance right?

Was wondering if anyone else has repaired/upgraded their radiator fans and could chip in any advice

Thanks in advance!!!

[skhannes]

Hi,

I thought I would offer a little insight to this system, although I have not worked directly on the cooling fans of an AM, but have on several other cars. In my experience with P0480/P0483, etc., the fans themselves are seldom the problem, but rather the fan control module has a burned out transistor, the signal wire, which is a PWM, coming from the ECM is frayed, broken, damaged, the high amp fuse (engine bay fuse block) is blown, or the relay is blown if this design uses an additional one to the ones located in the fan control module, finally I've seen the high voltage cable running to the fan motors literally melted, usually at the connectors.


About how it works:

The cooling fans are completely controlled by the ECM via a fan control module using PWM. The PWM is a ground, so, with every pulse the ECM is completing a ground to the fans through a relay(s) where amperage on the other side of the relay is quite high. I believe on the DB9 that is going to be 60 or 80 amps. As the pulses vary in speed, the fan motors then run at different speeds based on what the ECM needs from input from a temp control sensor. On ECM data tables, fans sppeds are shown as percentages.

In your case, the first thing I would do is test the fans directly. Do this by unplugging the fan control module. then use a jumper wire + battery voltage directly to the fans +v wire in the connector. Make sure a ground is completed too. If the fans come on (and run smoothly and quietly) then the fans themselves are not your problem. The real problem lies in one or combination of the following:

Fan control module
Fuse
PWM signal wire coming from the ECM.
Separate relay if there is one. It would be in the engine bay fuse box. Often this relay is the same relay used on other functions such as possibly the headlights, washer/wipers, etc. The easiest way to check this relay is just swap it with one of the others that are the same. If you clear the codes and P0480/83 don't come back then you found the problem.
Could also be the temp control sensor that sends inputs to the ECM so it can control fan speeds, but this would be last on my list of suspects, along with the actual fans.

Hope this helps.

[AttomoZ]

Thanks skhannes, will try to find out the root cause of my problem... I wanted to take the whole radiator fan module (so i can test the fan motor and perhaps look at the fan control unit) out but it proved to be a harder task than I imagined... I thought I could just unscrew the two screws on the side holding the module but the car's frame seem to be blocking upward mobility.

[Stevev8v]

My 2007 Vantage fans stopped working .Checked fuse, relay and fans all working ,and problem was one of fans stay broke ,other cracked[ plastic, repaired with fibreglass ] and fan was touching the radiator which stopped it from working and fan control module overheated and transistor and one capacitor over heated and burned . [They can be replaced by computer geek] unless your good with a tiny soldering iron]. While waiting for module to be repaired I put in a Jag X type module , [ its same but wire harness going around one fan to the main harness on X type is shorter than the Aston one so I made a jumper cable to connect both . and works a treat.[ and X type can be used as spare once Aston Module repaired and replaced ; There's a Utube video on Jag forums on replacing Capacitors and transistors on the fan controller module].