F355 HVAC ECU

I measured 1 K between the pins as shown on the picture, valve closed, the "bar" of the motor shaft is very close to its stop (not in contact with it).

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Fantastic. Thank you. You guys are the best.

 

So update. I've repaired the ECU. I have drive voltage both positive and negative for valve direction when my suspect motor is not connected. My motor will turn both directions directly connected to a battery. However with the motor connected to the ecu it will turn 1 way and measure proper drive voltage, but reversing the direcrion voltage drops to 1 or 2 V and no reverse motor movements
I'm tossing the towel till i can get my hands on a known good motor as mine has damage. I suspect its pulling large current in 1 direction.

Ecu repair photos for fun.
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Anyone have a lead a good replacement valve motor?

 

Looks like Ricambi has a replacement valve kit (albeit expensive and not plug and play)

https://www.ricambiamerica.com/63306400-valve-heater.html

 

new or old? Old post, but this gentleman may still have one...

https://www.ferrarichat.com/forum/posts/147023314/

 

Oh snap.. i didn't even check ricambi as i knew it was discontinued i figured it would just be NLA.

Bravo to Daniel to having a work around. Steep for what it is but I'm ok to support that as he's done the legwork and bracketry. You could spend a lifetime trying to find something that works.

I'm also all for it if it's a better unit that fixes it for good. The original bosch is rubbish.

I'll see if i can source a motor reasonably if not I'll just retro fit ricambi's. Not visible and my cars a driver anyway.

 

I sucked it up and got the Ricambi kit. Thank you Daniel for assembling this kit, quick shipment, and the service you do for this community!

Success!!! I've got open and closure as its supposed to. Just need to finish pinning new connector and re plumbing.

Feels good to have a little win once in awhile.

My motor was shot it had an internal failure that likely shorted things and likely took out the ECU circuit controlling it as well. I tried to fix the motor but it would draw large current in 1 direction and was a band aid attempt.

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Thanks for the update, Zamboniman. Is there any drilling or riveting required to mount the bracket or does it use existing fasteners/holes?

 

Looks like it bolts right up like it was meant to be there and you'd never know the difference. I'll post update pic when i get it there. After getting this far I hung it up to go spend some quality 4th of July time with the kids.

 

Baby steps. Bolts right in like it was always there. I tested operation good before I remade the connector. Still need to do final test and ensure no leakage before buttoning everything back up.

Pleased so far. You will need to cut the original plug off the car and crimp new pins. A proper stripping toll and special crimper for pin connectors is really needed to do this properly.
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Even with supposedly correct crimping tools, it seems to an art form getting those kinds of pins crimped properly. I don’t know why automotive pins and sockets are not more like older aircraft type contacts (with no tiny folding tabs). They gave you a perfect crimp every time with one squeeze of the tool handle.

Anyway, the installation looks rather neat.

 

If you can make the mounting adapter and wire connectors yourself,


Vintage Air 461170 Vintage Air Replacement Heater Valves | Summit Racing

https://www.summitracing.com/parts/vta-461170#overview

 

I considered trying this but there are no electrical details available in their servo controls. Without burning time, money, and possibly an unobtanium ecu not worth the gamble. They could have a custom motor or modified servi motor in the ricambi kit. In the end i took the costly but path of least resistance. What are the odds the off the shelf vintage air servo has the same electrical characteristics our ecu is expecting? Maybe maybe not. I wasn't going to forge that path.

 

Understood. But noting magical in there. They all work the same way. 12V the motor with the ECU switching polarity to reverse the direction as needed. A potentiometer is used to sense position by reading the voltage from the rotor.

I just posted this to help other in the future.

 

Just for completeness as I've found some wrong info in the thread.

IC mapping in the ECU
4. Recirc flap motor control
5. Air dist motor
6. Heater valve motor
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@LorenzoR's notes are probably correct in post #65, but not the interpretation of them in the posts after that.

https://www.ferrarichat.com/forum/posts/144988121/

I wonder if anyone has replaced the wrong individual chips using the information in posts #66, etc...

 

Yeah chip 6 was the magic bullet i have full functioning heater temp control now.

 

I ended up replacing 4 5 and 6. Here is the final wire routing of the valve installation.
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@ Zamboniman308 Is that thing on top of the motor marked "RL" an indicator of valve position, a manual override, or just a fixed part of the case?

 

Unfortunately just the shape of the motor housing.

 

Another update. My recirculation flap wasn't operating. After the ECU repair I determined the motor was also faulty. I dug in a little further (which requires some destructive disassembly) and found the grease had turned to wax and the motor stuck. Simple DC motor no magic in here. Through electrical cleaner and exercising the motor got it operational but still would not start reliably in both directions. More soaking in cleaner more exercising. Back in business. Reassembled tested good to go. Carefully epoxy case together ( gears come awfully close to seam in 1 area ) and install in car. Boom air circ door functional again. Side note I chased my tail and scratched my head for a bit in defeat and decided to finally just start the car as I was attempting to test just turning on ignition. Not until starting did it work.

I fully expect its only a matter of time to have to get the metal boss from Hill Engineering now that the motor is back to business.

Moving along with the little things as time allows. I'm now more convinced that failing motors aren't doing the ECU any favors.
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Replaced all 6 chips. Stuck on heat sinks that have thermal tape, hopefully it helps.

 

I have repaired the ECU module but now i have the next problem with the HVAC controller, it seems someone did a bypass for the fan control and removed the rotary switch, also missing the light bulb on right side.

Anyone know where i can get this rotary switch? it seems old and made by ITT back in the day, see picture...
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https://www.ebay.com/itm/303370569090

Maybe?

These switches may be very specific. Look at the table in that advertisement.

Is there a part number on the other switches?