jyspark
2/1/2008 11:18:35 PM
I have a 1998 Range Rover 4.0SE.
Recently, I found the real air springs bad (leaking) and replaced therm.
However, although the replacement, the RR did not raise its height, but the height adjustment light (on the center fascia) flickered continuously.
The reason is that the air compressor does not work (not vibrate even though the ECU is sending signal).
I disassembled the aircompressor unit and found that the motor is working but the thermal switch is open.
After cleaning the inside the air compressor, it worked shortly, but stop working again.
ANY IDEA HOW TO MAKE THE THERMAL SWITCH CLOSED?
WolfPack
2/2/2008 6:30:05 AM
If I'm not mistaken the thermal switch is part of the compressor itself.
I found on RangeRovers.net this info about repairing/diagnosing the compressor. In this case he had a few problems with the compressor, but the thermal switch was the 'immediate cause', and he just wanted to inflate the springs to test.
quote:
If voltage is getting to the compressor but it does not run, the problem could be the thermal cutout switch falsely telling the ECU that the pump is overheated. (The compressor is only rated for about 15% duty cycle at maximum pressure, hence the need for a thermal cutout). In my case, although the pumping was becoming slow and the bearings were getting noisy, the failure of the thermal cutout was the immediate cause of failure. This switch (the third and thinnest lead, colored orange, emerging from the pump motor body) is normally connected to the ground lead of the compressor; it open circuits when the operating temperature gets too high. On mine, the cutout switch open circuited for no particular reason, telling the ECU that the pump should be switched off. I was able to get the system going again by grounding this lead with a jumper.
jyspark
2/2/2008 9:20:10 AM
Many thanks
WolfPack for your kind post reply.
After carefull examination of the thermal switch circuit on the inside cover of the compressor motor case, I thought I would try to test and replace the malfunctioning parts of the circuit. I think with proper electronic tools and a tester, the thermal switch circuit would be fixed.
However, as you suggested, connecting the orange wire to the black wire with a jumper is the simplest solution for the compressor motor to work without the thermal switch interruption.
Many thanks again.
John
