Dakota air conditioning issue

130 MILES • 6 CYL • 2WD • AUTOMATIC
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SLADE25
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97 Dakota 3.9L auto. AC issue
Recently I put a full can of 134A refrigerant into my a/c system. Took the full can, no leakage, all seemed good. Prior to this the refrigerant reservoir had been empty for some time so there was no cooling if I selected a/c. Didn't really need it. This year with hotter temps coming I thought I might need it. So I decided to put some refrigerant back into it. It took the can nicely, got up to about 120psi while putting it in (followed manufacturers directions totally). As it was going in the compressor started to activate, this was a first for me (not orig owner). Afterwards I did (and do) have cooler a/c when selecting a/c.

However now when I select any other of the non a/c venting the compressors continues on, as if it thinks it is in the a/c mode. There are no fault codes coming up. So in a nutshell, I have a/c but I have the compressor working when it is not in a/c mode, which it never did prior to putting new refrigerant into the system. Any ideas what is causing this ? Anything I can check or do to stop this from happening ?
Jul 27, 2011 at 12:48 PM
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WRENCHTECH
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That is normal. They are wired to run most of the time because it removes moisture from the air.
Jul 27, 2011 at 1:28 PM
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SLADE25
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are you sure about that Wrench ? It never did that ever before ??

I thought the compressor is only supposed to come on when the A/C is being accessed. It should not be coming on when selecting the non A/C venting. I've not experienced that with other vehicles.
Jul 27, 2011 at 6:42 PM
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WRENCHTECH
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In your case it runs in both A/C and defrost modes. Some other vehicles run it most all the time.
Jul 27, 2011 at 6:47 PM
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SLADE25
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OK, didn't realize that, sounds a little weird. Any idea why compressor is only coming on now for the non A/C selections ??
Jul 28, 2011 at 2:27 AM
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WRENCHTECH
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That would be determined by the mode selector in the control head.
Jul 28, 2011 at 2:52 AM
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