F355 heater (again sorry) and cooling fans

I think you'll find that everything from the aft cabin bulkhead rearwards is the same on LHD and RHD* cars, but anyway, the fans are independent. According to the Workshop Manual (WSM), the left hand fan (nearside on your car) is controlled by engine coolant temperature and the right hand/offside fan is controlled by oil temperature (since the oil radiator is "in series").

Anyway, congratulations (on your purchase and finding a hot water valve motor). Hopefully the HVAC ECU knows how to control it when you hook everything back up.

*other than regional/country variations

 

Indeed, since the ecu controls that motor to open and close the valve. I wonder if there was anything wrong with the original motor? Was it tested prior?

 

Good to know. Thanks.

So you've applied 12 volts to the actuator connector and you can see the gearbox output running in both directions off the car? Have you also checked the potentiometer in the actuator?

Here's the wiring diagram (5.2 car):

5.2 HVAC Wiring Diagram

Are other control panel functions operating (air direction, fan speed, etc)? Have you read the message threads on ECU driver chips? The control panel is not the brains of the system.

 

If the motors bench test ok, unfortunately the problem most likely will be in the ecu. This is a common condition and there are companies that will repair your ecu. I have seen this many times before. Fortunately for you, i believe the repairer for your ecu is indeed based in the usa.

 

Ok, well you will have to ship it for repair as i have in the past...

 

https://www.autoecu.com/climate-control-programmer/ferrari-355-360-430-climate-control-programmer-computer-repair-service/

Or you can take it to an electronics shop and have them replace the numbered chips. Chip 5 controls the heather valve motor as I understand.
Image Unavailable, Please Login

 

By the way, what year Saab was the valve motor from?

 

1998 Sabb, thanks.

That's is how mine failed. No power to the motor. Fortunately My car is a spider and I only take it out when it's top down weather. But it failed "open" so I was out driving in 90 degree weather with the dam thing blowing full hot. At least I was able to shut it off but I like to run with the AC on when it's that hot. I was able to close the valve later by applying 12V to the motor, and there is stays. I have the chips to replace in the ECU but haven't gotten around to it since I don't really care about having heat. Plus, I want to have someone hook up an SD2 and check what the ECU is doing before I start replacing chips, just in case it is something else.

 

The valve actuator has a feedback (potentiometer) circuit. There may be no output from the ECU if you don't hook up the potentiometer wires (to the ECU) when doing your tests. That's why I asked you if you'd checked the potentiometer.

Note also, the earth (ground) for the potentiometer may be inside the ECU (despite what the wiring diagram shows). A local chassis earth may not be sufficient.

 

By the way, the Bosch part number appears to be 0390721006. Used on Saab, Fiat, Alfa, Lancia

Image Unavailable, Please Login

 

I have a thread about changing out the Bosch motor. Please note the last three digits "917" are relevant. I can't remember if that is the exact number or not. I will have to find the thread and report back. As I bought a couple of these, and one worked and one did not work correctly. And the only difference between them was the last three digits in an oval.

FOUND IT:
"Important info on Bosch part #0 390 721 006! These are discontinued, and you can source them from Saab used parts dealers (from a model year 2000 Saab 9000)

--------------------------------------------------------------------------------

There is an important sub part number to this item, I just learned today. There is a number in a circle "944" after the main part number Bosch part #0 390 721 006

It is important you get the one with the "944", if you get the one with "917" the operation is reversed, and it won't work! I got mine from a Saab breaker parts dealer and he had both. I got lucky the first time, and it worked perfectly. Today, I was helping a friend fix his, and got one with "917" on it, and it worked in reverse. We called the Saab specialist and he admitted there are different versions and he was at a loss to know which was which, but when we checked my car, my old broken one, and the one we removed off my friends car, all had "944" in a circle after Bosch part #0 390 721 006.

Both the 917 and 944 are used on the Saab 9000, so very important to get the right one. "

 

Are you sure about the last 3 digits? I have seen both 917 and 944 listed as being from F355, 348. The difference being 917 is marked Made in Belgium and 944 Made in France. As far as operation, simple fix by either reversing the proper leads. Being a reversible DC motor, which way it rotates just depends on the polarity of the applied voltage. Also, the Saab 9000 ended production in 1998.

Image Unavailable, Please Login

Image Unavailable, Please Login

 

I have simply posted my experience with two 355s where I replaced this motor. Perhaps one can start modifying the wiring, but that screws the next owner to figure out. The proper ones are readily available with a few phone calls. I don't know about the years of Saabs from personal knowledge, I only was given the information from the Saab breaker yard I obtained the part from, and that was what was printed on the tags on both parts. If they were in error, I apologize for passing along bad info.

 

Thanks for the clarification as both are being represented as for the 355 on the market.

 

Now your previous post makes total sense to me Mike, ,thank you! 917 is a simple part swap. 944 will still work, but requires removing the motor from the housing and swapping with the original one. Got it.

 

My 355 keeps blowing the 30amp fuse, the car came with a circuit breaker so I keep resetting the fuse, it trips again within seconds.

is this a known issue? And is there a fix?