volvo ec140b cab fan stays on with key off, changed relay no change
What other functions remain powered up?
Only the temp readout light,Before fan would stay on for 30 sec after shutdown as if it had a timed relay
The diode suppressor has likely failed on the fan circuit. I will look for the schematic, if I have it saved.
Ok, here's the ugly truth. The schematics are no help. They show power and sensors between A/C controller and control panel. The only consumer shown is the A/C compressor. That said, look at relay RE8701. That is feed to the blower. See how it has a resistor integral for spike suppression? That resistor may be open. For testing purposes, you could swap with your horn relay. The relay box is mounted behind the plastic cover directly above the battery box. It's a plastic box maybe 6x10. We can help further, but it will be by description not by schematic. Good luck Thank you Uffex for posting up the schematic.
Replaced relay 8701 no difference
Is this on all fan speeds or on high only?
would there a timed relay in the system, because the fan would run about 30 sec after key off before?
I will check
No, no timer delay for A/C only delayed shut down for ECUs so they can save info .
I'm thinking your motor is becoming a generator, and keeping itself running until it winds down. That's the job of the diode in the motor.
I'm guessing, you're going to need a motor and resistor. It's a pain in the butt job, everything is behind the seat.
Fan will speed up, cold eng and all shuts down, little warm and back to running.found a fault code er14,manual says j1587 (slow link) what ever that means
That means you have a communication problem between the V-ECU and the E-ECU. You didn't use the relay labeled data or EMS, in the box, did you?. Was everything in the relay box nice and tidy it loose and falling apart. Its common to find all the screws backed out.
volvo says all I have is a ECU no VCU
That's right , the 140 uses the mechanical 4 cylinder deutz. A lot of things on the 140 are unique. From 160 to 460 everything was common. You still have communication between the MDU & V-ECU & A/C controller. In the right armrest, beneath the MDU should be a bulbous plug with 2 wires, it should be blue or black. On the body it should say 120 ohm. That is your terminating resistor. Key off, battery off. Measure that resistor, verify 120 ohms, then measure the plug it plugs in to. You should have 120 there as well. Then plug the resistor back into the harness. Back probe the connector, you should now see 60 ohms. If this all checks out, measure against ground, see if its shorted, possibly. Good luck. Wish I could help more, this is gonna require the service manual specific to your machine
waiting for a mechanic, will keep you informed, thanks for your wisdom
code now is A 8 ?
looking at it again it might be R8
check ohm's all good