Wiring for the 355 blower timing actuator

I got some teeth broke off the gear in the blower timing actuator 63307100. When glued the teeth back in-place I learned the actuator not spinning at all with the engine and blower/AC on.

The power to the actuator is coming on Black and Red wires.

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The actuator motor itself shows connectivity OK between both connectors on the electrical motor meaning the wires in the motor are OK and not burnt off.

Incoming power to the actuator motor is coming to the Red and White-Black wires.
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There is no voltage coming to the Red/White-black wires when the engine is running and AC is blowing to the actuator. In the climate-control panel the wires in the connector are thinner and different color scheme.

There is 30A fuse in the front trunk on the RH side of the blower radiator box wall and that fuse is for the blower itself (which is working) and for the AC pump clutch (and the AC is working).

The internal/external air door is also not working/kept always open.

The fan changing its' speed reacting on the fan speed knob position change. The button STOP on the climate control panel stops the AC as it should.

Where the voltage to the blower actuator is coming from?

 

From the HVAC ECU in the front luggage compartment:

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Thanks to @eric355 for the photo

Location varies on earlier cars (I see you have a 1999 model)

Wiring diagram here:

https://www.dropbox.com/t/kdl222BdEXFZRwcR

See 01262 at the bottom of the diagram.

Hopefully just a broken plastic driveshaft. Easily fixed with a Hill Engineering / Ricambi brass boss

https://www.ferrarichat.com/forum/threads/what-is-this-piece-and-where-does-it-go.675584/#post-149081256



https://www.hillengineering.co.uk/other-parts/recirculation-boss

If the drive is ok, then maybe the teeth in the gearbox have failed or the driver chip in the HVAC ECU has failed. Lots of message threads on these (including IC part number, which of the 6 driver chips drives what, etc.)

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Thanks to @Zamboniman308 for the photo

 

Glued? Several folks have produced 3D printed gears. e.g.

https://www.ferrarichat.com/forum/threads/355-hvac-vent-direction.266756/

 

It's not the gear. My glued gear is OK. The actuator is not spinnig no power to it. And I already got a 3-D printed gear.

 

The motor power should only be present when the actuator is told to move to a new position. I assume the potentiometer power on pin 3 (yellow wire) should be there whenever the ignition is turned on.

 

I already have replace the draveshaft on the fresh air flap to the LH engineering one many years ago. Appearing none of both actuators get power to operate.

Seems the power for the flap coming from pins #22/23 of the connector 10520 and the power for the timing actuator to #18/19 it's not showing on the diagram what is coming to those pins from the other end?

 

The power is coming from the driver chips in the ECU. The ECU is powered by fuse 24 (on the 5.2 car) though pin 3 when the ignition is on and by the battery bus bar behind the passenger footwell relay panel (at all times) through pin 1.

If fuse 24 was blown you would have other major issues.

 

Correct. The problem is when changing the airflow direction knob no voltage comes to red/black pins.

And yes. When the ignition is on there is +5V on the yellow wire pin.

 

Not including the potentiometer power. Your tests basically prove that the driver chips are kaputt or there is a power supply issue somewhere in the ECU.

Did you try a long term/overnight battery reset?

 

The climate-control ECU or Motronic that controls the engine?

The airfan fuse 10A in the passenger foot-well is OK.

 

The climate control ECU in the frunk.



I think all the Motronic ECU does is stop the AC compressor running when you put your foot to the floor.

 

SOLVED.

A great mind thinks alike. When you was typing it up on the other end of the Earth I was opening the front trunk and turning the Ground switch off for the car battery.

Turned the ground switch back up after 5" and both actuators are working. Original glueded by an epoxy glue gear is spinning.

Time to glue back together the actuator box leave it overnight and tomorrow morning eveything will be back in place and now it's a time for a 6-pack.

Big relief.

 

Thoughts from the troubleshooting:
- When the timing actuator gear teeth broke off the actuator kept spinning and the position sensor kept reporting the same position of the gear. The ECU based on the feedback from the sensor cut off the power to both actuators to not to burn off the electrical motor for the timing actuator. The power reset for the ECU flushed the ECU memory.

 

Makes sense. I think my car is overdue for a timer actuator replacement, so I'll keep that in mind.

 

I think that might be related on which setting you keep the airflow direction knob. I keep it to AUTO 99% of the time so to my understanding it changes the direction of airflow constantly or often if you have the knob to one of the manual positions changing it rarely the original gear might last longer.

I am looking forward to see for how long the glued original gear would last? I already have bought a 3-D printed replacement as mentioned earlier in this chat.

 

Indeed. It seems that my actuator hunting on startup issue is not an issue. I pulled my actuator out and checked it on the bench. All ok. No dead spots and the potentiometer resistance checks were ok.

Not sure how difficult it is removing and installing an actuator on a LHD car is, but on my RHD car wasn't easy at all. It was easy to find/see with your head under the dash, but getting your hands in there was an absolute pain. I made more room by removing the Window ECU, which was hard enough. Who designs a counter-intuitive plug that needs to be moved sideways first before pulling/rotating it off? At least there is only one bolt holding the Window ECU in.

The timer actuator connector is a friction fit (no clips). Unfortunately, two hands are needed to separate the halves ... as well as double jointed elbows to get past the pedals. You also have to be very slim to fit between the steering wheel and the driver's seat, otherwise you would have to remove the seat. The two mounting screws came out easily enough with a stumpy screwdriver.

Refitting was just as difficult. You have to do some mental gymnastics to figure out how to align the actuator drive shaft with the index mark on the tambour shaft.. whilst standing on your head. Nip up the mounting screws. Don't overtighten, as those mounting feet don't look too strong.

 

For the LHD cars it's a pain in the butt as well. With a little advantage of a non-presence of the steering wheel column and the pedals.

I didn't remove anything to get to the actuator but the space is so tight (and I needed to hold a flashlight with my LH) doing the work RH only. The only working position was lying on my RH ribs. Tightening the screws at the end so the actuator is not loose was a real pain. I was able to achieve it only by sitting on the RH seat moved it all the way fwd.

Also a FYI if you take out the actuator and try to see how it's workng hanging in the air my actuator shaft was turning back and forth a bit then returning to the same position regarding which airflow direction I was setting on the climate control panel. Even after I had put it back into place. Another battery switch reset did the memory flush again to the climate control ECU and it started working as intended. I think when you operate it while taken out the ECU detects the actuator motor takes less electrical power than when loaded and returns it back to the some "default" position regardless of a command from the control knob. And why it's keeping doing so when I had put the actuator back in-place - I think the logic is once the ECU detects any deviation from the actuator from the expected responses - it's halting the operation until a human intervention with a confirmation all been addressed in a form of the power reset.