xj40 heater blower problems
#1
01-15-2017, 03:58 PM
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xj40 heater blower problems
Hi Guys,
I've a question about the heater blowers in my XJ40.
The car is from 1990.
The blower motors were under water, so the motors were stucked and rusty.
Fuses blown out, but thats not weird.. when there's a liter water in each motor!
I have mounted two other motors with good resistances in it.
Also renewed the ECU for the climate control, and the switch for the 0 low medium and high.
So now, the problem is, the motors are only working on the highest stand.
When i switch from 0 to low, the fan turns 1 or 2 times.. and stops.
So power comes in, relays are clicking...
Everything looks fine, but WHY are the blowers just starting up,, and stopping almost direct..
Can someone help me with this problem.
Thanks!
I've a question about the heater blowers in my XJ40.
The car is from 1990.
The blower motors were under water, so the motors were stucked and rusty.
Fuses blown out, but thats not weird.. when there's a liter water in each motor!
I have mounted two other motors with good resistances in it.
Also renewed the ECU for the climate control, and the switch for the 0 low medium and high.
So now, the problem is, the motors are only working on the highest stand.
When i switch from 0 to low, the fan turns 1 or 2 times.. and stops.
So power comes in, relays are clicking...
Everything looks fine, but WHY are the blowers just starting up,, and stopping almost direct..
Can someone help me with this problem.
Thanks!
#2
01-15-2017, 06:21 PM
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Hi jaguarxj,
Welcome to the Jaguar Forums! It's great to have you with us.
First of all, did you install entire different blower motor housings and motors, or did you install different fans & motors in your original blower housings? If the latter, I would suspect that your speed control circuits are not operating, probably due to the water or else just because they fail over time.
One of the relays in the blower housing is the isolation relay that provides the master power for the blower fan and circuitry. The other relay is the high-speed bypass that bypasses the Low-Medium speed control circuit and applies 12V directly to the fan motor. The fact that your fans will run on High means both relays are operating properly, though if they are original non-sealed relays I would recommend replacing them with new sealed relays.
For the Low and Medium fan speeds, the power passes through a speed control circuit that uses a Darlington transistor as a variable resistor to reduce the voltage to the fan motor. The transistors tend to fail over time, as do other components on the circuit board (some resistors and diodes).
The XJ40 eBook has a good explanation of the system and tells you how to rebuild the circuit:
Jag-Lovers XJ40 eBook Air-Con Blowers
Check it out and let us know if you have any questions.
Was it just your blower motor housings that were full of water, or was the entire car flooded?
Also, as soon as you get a chance, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.
Cheers,
Don
Welcome to the Jaguar Forums! It's great to have you with us.
First of all, did you install entire different blower motor housings and motors, or did you install different fans & motors in your original blower housings? If the latter, I would suspect that your speed control circuits are not operating, probably due to the water or else just because they fail over time.
One of the relays in the blower housing is the isolation relay that provides the master power for the blower fan and circuitry. The other relay is the high-speed bypass that bypasses the Low-Medium speed control circuit and applies 12V directly to the fan motor. The fact that your fans will run on High means both relays are operating properly, though if they are original non-sealed relays I would recommend replacing them with new sealed relays.
For the Low and Medium fan speeds, the power passes through a speed control circuit that uses a Darlington transistor as a variable resistor to reduce the voltage to the fan motor. The transistors tend to fail over time, as do other components on the circuit board (some resistors and diodes).
The XJ40 eBook has a good explanation of the system and tells you how to rebuild the circuit:
Jag-Lovers XJ40 eBook Air-Con Blowers
Check it out and let us know if you have any questions.
Was it just your blower motor housings that were full of water, or was the entire car flooded?
Also, as soon as you get a chance, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.
Cheers,
Don
Last edited by Don B; 01-15-2017 at 06:23 PM.
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#3
01-16-2017, 11:05 AM
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[QUOTE=Don B;1602996]Hi jaguarxj,
Welcome to the Jaguar Forums! It's great to have you with us.
First of all, did you install entire different blower motor housings and motors, or did you install different fans & motors in your original blower housings?
Yeah, I installed complete other used blower motors. Included the housing, resistance etc.
For the Low and Medium fan speeds, the power passes through a speed control circuit that uses a Darlington transistor as a variable resistor to reduce the voltage to the fan motor. The transistors tend to fail over time, as do other components on the circuit board (some resistors and diodes).
The seller told me they worked in his car on all speeds. Maybe he's lying...
The XJ40 eBook has a good explanation of the system and tells you how to rebuild the circuit:
Jag-Lovers XJ40 eBook Air-Con Blowers
Thanks!
Was it just your blower motor housings that were full of water, or was the entire car flooded?
Yep, in both blowers was a liter of water.
Also, as soon as you get a chance, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.
Dit it, thanks!
Welcome to the Jaguar Forums! It's great to have you with us.
First of all, did you install entire different blower motor housings and motors, or did you install different fans & motors in your original blower housings?
Yeah, I installed complete other used blower motors. Included the housing, resistance etc.
For the Low and Medium fan speeds, the power passes through a speed control circuit that uses a Darlington transistor as a variable resistor to reduce the voltage to the fan motor. The transistors tend to fail over time, as do other components on the circuit board (some resistors and diodes).
The seller told me they worked in his car on all speeds. Maybe he's lying...
The XJ40 eBook has a good explanation of the system and tells you how to rebuild the circuit:
Jag-Lovers XJ40 eBook Air-Con Blowers
Thanks!
Was it just your blower motor housings that were full of water, or was the entire car flooded?
Yep, in both blowers was a liter of water.
Also, as soon as you get a chance, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.
Dit it, thanks!