About two weeks ago, I was out for a drive. Temperature was about 105 degrees, which is not unusual for this time of year in Las Vegas.
Suddenly, my temperature gauge started steadily heading up from center which is very unusual since it’s been rock steady since I’ve had the car.
Fortunately, I was about a mile from the dealership, and the red light and shut down the engine warning came on just as I pulled into the service area.

Dealer diagnosed a defective cooling fan assembly, but stated that the part is on back order. Given the forecast for record temperatures (~120 degrees), and the fact that the dealer has no indoor storage, I had my Vanquish sent home via flat bed to my air conditioned garage to protect it from the sun/heat. It’s been two weeks with no ETA from the factory on the part. I’ve checked multiple suppliers with the same response that it’s back ordered from the supplier.

I’m not sure how AM cannot keep this part in stock or on a short delivery time from the vendor since it is used across its entire V12 product line. I’ve owned two other DB9’s and never had this issue with parts availability.

Has anyone else experienced this?

Thanks,

Jim

 

I think Aston Martin Bits has one. Says compatible with all years Vanquish. Assuming your dealer will install it or your local indie shop will.

https://www.astonmartinbits.com/mode...2-4/parts/1700

 

Too bad something like this can sideline the car. It's unfortunate this is being sold/replaced as an assembly as it contains parts that are common that wouldn't be unique to AM.
This assembly contains:
2 fans with motors
1 control module
a harness
a frame to hold the parts which might be the only part that AM could have designed and had built. All the other parts are purchased from catalogs and likely common with other cars. That's the way a boutique car builder does it. Actually, the way many car builders do it.

If I had access to it I am confident I could get it back running. I would bet the fan motors (fans) are perfectly fine. 99% of the time the controller goes bad, usually burns a transistor. The control unit uses a PWM signal directly from the ECU. The PWM is a ground, the fans stay wired to +voltage and the pulse makes ground at varying frequencies to satisfy fan speeds the ECU wants. I've had a few encounters with these on other cars and almost always the controller went bad. In a couple of cases it was actually the relay burned as these are very high amperage. Assume the first check the dealer made was the relay.

If I had access to it I could check the fans in a matter of minutes, then I'd work directly on the controller. If I had it I bet I can source it.

 

Thanks all for your comments and suggestions.
I’m going to do a bit of troubleshooting while waiting to confirm the info above.

 

There is a cross reference parts list floating around the internet. I have some of it but can’t seem to copy to this page. Sorry. Not 100% sure but isn’t the fan set up from a Jaguar or parts of the fan assembly?

 

Thanks again to everyone.
Lead time from fan assy. manufacturer to Aston Martin is mid-September.
Did some troubleshooting to confirm what the dealer is telling me that it's a bad fan.
Car starts, comes up to temperature and is stable. Small fan runs, but the larger fan never starts, even with the AC system on max and driving the car at temperature. I'm assuming (maybe wrongly) that both fans should run together and vary the speeds depending on engine temperature.
80a cooling fans fuse is nice and tight in the fuse box.
I cannot get to the large fan connector to test it from above, but will get the car up on the Quick Jacks when I return from vacation in a few weeks to disconnect the fan, test it and work my way back to the fan control unit if needed.

Thanks again.

Jim

 

Finally got the car up in the air to test the large radiator fan.
First time with the Vanquish with QuickJacks. I needed to single point jack and place a 2x6 under each wheel to get the clearance needed for the carbon skirts.
Plastic under tray is a dream to handle compared to the metal one on my DB9.
Once the tray was removed, the fan module and fans were right there. I unplugged the large fan and connected 12v to it and it ran for quite a while with no problems.
I removed the fan control module and searched on the part number. It seems to be a Volvo part, but Volvo as with Aston Martin only sells the complete fan assembly. I found several new modules on EBay and ordered one for about $50.

JC

 

Amazing, JC. Thanks for posting an update.

 

Thank you for the detailed writeup for future reference/search

 

Excellent....thanks for posting.

 

Nice work.

In the several instances I've had with these modern fan assemblies where ECU is controlling fan speeds via a PWM ground signal, the module was almost always the culprit. Once you get the new (Ebay) part, if you can remove the cover on the control unit, I would bet money a burned transistor.

In the second pic in post #7, on the input side of the controller, there are two large wires coming in (+vs to each fan) then the much smaller yellow wire is the PWM coming from the ECU. In a couple cases I found a wire failure (not delivering the ground pulses from the ECU). That would not be your case as one of the fans is running normally.

Varying fan speeds are chosen by the ECU based on pulse widths and using inputs from other sources. When I was tuning, I could change the fan speeds based on what I needed to accomplish in a given tune. Here is an example of a fan speed data table in a tune. The ECU uses a base table then another one if AC is running. The numbers in the cells are percentages (0 to 100%). Fans are never set to 100%. The charts below are factory settings from a GM car, but all mfgrs are doing it like this.