1998 Honda Civic Compressor Fails to engage

1998 HONDA CIVIC
214,000 MILES • 4 CYL • 2WD • MANUAL
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CL65AME
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I have been troubleshooting this for a while. had it to the dealer and got some useless feed back.
The AC system is correctly charged and serviced.
The AC compressor clutch will not engage. I have carried out all of the TS in the Honda Service Manual and the only thing I can surmise is that the ECU is not supplying a ground to the Clutch relay. The wire checks fine from the A17 connection on the ECU to the under hood relay/fuse box. There is power at the pin when connected but the relay (which is fine) does not latch. If I supply a ground (through the back probe) to A17 the relay latches and the compressor engages.
I can only assume that the ECU is not supplying the ground for some reason. I am not sure what other functions affect this ground being supplied. I do not have a schematic of the ECU to see what other inputs are required to supply the ground.

Right now I have jumpered the Relay connections to supply power to the cluch through a manual switch.

HELP
Jul 11, 2008 at 8:34 AM
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KHLOW2008
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Hi cl65ame,

The ECU is faulty. There is no ECU schematic available. If you want to try DIY, open up the ECU and look for leaking condensers, replacing them might solve the problem.
Jul 11, 2008 at 11:08 AM
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CL65AME
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as I thought. thanks
Jul 11, 2008 at 11:15 AM
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