Power Stage Part Numbers Topic is solved

[Navy]

Thank you Neil and Rick,
Neil, I photographed the front of my ecc as I cannot see the C or F markings. I may have missed something as I am somewhat overloaded/lost with sorting this out.
Rick, I opened up the ecc as you suggested but again with a somewhat foggy head I could not see any diagnostic switch/button so again I snapped a picture incase I've missed something.
I could not recall taking the voltage readings at the blower resistor so I did so again which may be telling or not.

I unplugged the connector at the fan blower (red and blue connector) and the ecc lights still flash.
using my dmm on the blower resistor 4 wire connector
4A has 11.58V red wire
2A Violet white wire 0.12v. when I turn ignition on the blower runs and the volts increase to 0.96 then 0.71 then 0.68.....lights flash and then 0.12v
3A grey/red 10.81v
1A yellow/brown, ignition on blower runs 2.68v 2 seconds later lights flash then 0.15v.

2A 3A and 1A exactly the same results at the rear of the ecc green connector.
1A no idea where this is perhaps fuse?
Many thanks again for all the help and advice.
Andre

[RickHaleParker]

9134769 is Celsius. It in the compatibility table.

Can you pull the ECC diagnostics codes from the jumper type diagnostics port under the bonnet?
On some of the older pre-1999 ECC you can pull the codes from the front panel of the ECC. I don't recall now it is done.

[Navy]

Thanks Rick,
I deleted the dtc codes for B1 under the bonnet and turned the ignition on and rechecked. I really am no further on as code 124 and 419 still pop up.
I know 124 is a issue with the sensor above the grab handle on the driver's side which I hope to sort out along the way.
419 is still there. I have now paid for a repair to my original 9144355 resistor and the diagnostic still threw up 419. I purchased 9166694 in the hope and good luck...maybe! and the diagnostic still threw up 419 and I purchased another 9166694 because I am desperate and the diagnostic is showing 419.
It's maybe plausible that Dtc 419 is correct because I am installing the wrong blower resistor but I am now thinking perhaps the ecc is at fault.
London was -1 this morning and I have yet to find a suitable wire to rig between the blower motor and earth.
Thanks again
Andre

[RickHaleParker]

B1-419 Power stage. Faulty diagnostic signal

Condition
If the diagnostic signal from the passenger compartment fan power stage is missing or faulty, the control unit records the fault and stores the DTC.

Possible source
Open circuit in wire across control unit and passenger compartment fan power stage or internal fault in passenger compartment fan power stage.

Fault symptoms
Fault warning to driver. LEDs by A/C and REC buttons flash for 20 sec. Control unit shuts off passenger compartment fan.



I would try to fix the B1-124 also.

B1-124 Driver's side passenger compartment temperature sensor. Open-circuit or short-circuit to supply

Condition
If signal from passenger compartment temperature sensor is missing or shorted to 12 V, the control unit records the fault and stores the DTC.

Possible source
Open circuit in passenger compartment temperature sensor or wire, or short in wire to 12 V.

Fault symptoms
Fault warning to driver. LEDs by A/C and REC buttons flash for 20 sec.
The control unit substitutes the faulty signal with an estimated value based on the desired temperatures from both temperature switches and the sensor signal from the side which is working. If the sensor signal is faulty on both the driver's and passenger side, the control unit uses the temperature value from that side's temperature switch only.

[Navy]

Thanks as always Rick,
Ok, I decided to take your advice and start on the driver side temp inlet sensor. I can see it spinning for a few seconds then the little fan stops. Blew the dust out with compressed air but even after wiping the dtc the same code 124.
So I decided to remove the sensor. Maybe I am missing the obvious but that was one of the most awful difficult cumbersome part I have ever removed from a vehicle in 40 years. Seriously, what were the designers thinking placing that second screw up high? Surely a slide in snap type removable clip thing drop down pull twist squeeze wiggle would suffice. Anyway, It's out and I think I may have the problem in my sights........hopefully a straight forward repair...Ahem! (see previous 35 posts).
I have attached a photo for repair tips...if any.

Happy holidays to everyone and I hope it's a wind of change for 2022.
Kind regards
Andre

[scot850]

As Rick says, your unit is in degrees C not F.

I suggested a while back to swap the sensors over from left to right and the reverse for the other to see if the fault transferred. That would highlight if the sensors were at least good. If the sensors don't work they can stop the ECC unit from getting a signal which in turn stops the power stage from switching on. It may not be the case in your unit but now you are in there it will be interesting to see how this pans out.

Good Luck.

Neil.

[RickHaleParker]

Looks like a RTD with Capacitive noise filter. If some body can figure out the resistance curve. A new RTD could be wounded and the sensors could be rebuilt.

Do you have a part number now?

[Navy]

Thanks again Neil & Rick,
I may not have been clear in my last post but I decided to deal with dtc 124. This is the inlet air temp sensor above the driver head behind the grab handle. Clearing with compressed air is the go to solution but in my case this did not stop 124 dtc. I removed the sensor and disassembled it.
If you look carefully you can see a break in the thermistor wire (lower part of picture) probably due to corrosion which the wire is covered in. Anyway, a clean up and solder repair of the broken section provided me with a continous running fan and no more dtc 124.
I went for a 30 minute drive since the roads are absolutely empty in London and rechecked the dtc and no more code 124.

One down and one to go dtc 419 but I have a cunning plan for that.
Kind regards
Andre

[scot850]

Well done on that one! Finding a small break like that is hard to find, and fixing it is very well done!

I'm out of my depth on the 419 issue though. Good luck with that!

Neil.

[Navy]

Neil, Bloody hell, half the work was finding a suitable head lining adhesive spray. I was so careful to be gentle but the sensor is very deep and the upper screw is tricky. On reflection, I could have easily made a suitable instrument to remove the upper screw but by this time the dtc 419 was starting to P*** me off and I felt the need to accomplish the 124 outright. The hardest part removal of the surrounding plastic (can easily break after 27 years) gently, even so, I may have two minor cracks. I would not even bother to attempt the passenger side.
Anyway, DTC 124 gone and the repair is working fine. Sadly, at the smallest chance....out comes the phone torch and a quick scan to ensure the motor is spinning......this is, and may become OCD....no offence intended!
One less DTC......
Right, next one 419.
Andre