MARK VIII & DC Control Problem?

HISSIN50 said:

As you know, an email to Brian would be good.

Where is the controller located? Is it near the perceived source of the noise? Is the DC wiring at the battery/solenoid connected tightly and clean? Is the fusible link in distress? Those connections need to be pretty impeccable with a PWM device IMHO.

"My controller is located on the Mark VIII shroud on the pass. side of the car. My connections are clean. The car is always garaged and hasn't been washed or in the rain in 4-5 years...very clean under the hood. However, I will check the fusible link."

Make sure your AC clutch wiring at the clutch is ok and that the insulation is not coming off.

"Wiring at clutch is OK, insulation OK."

You could try sourcing a new AC input location. Most folks tap in at the AC clutch. I prefer to tap into the AC feed before the LPCS (so the input to the controller doesn't cycle with the AC. The delta unit has hysteresis built-into it to accomodate cycling but I still prefer to tap the feed into the LPCS).

"I tapped into the A/C clutch wire directly on top of the compressor."

On earlier stangs, it's light green/purple. Not sure on later models but it's super easy to test (if the LPCS is unplugged, it should be only wire that shows 12V when the AC knob is turned on). This is worth a shot in case the rest of the AC wiring has an issue (the WOT socket vulcanizes and the wires short, and the feed to the clutch has a diode).

"Thanks for the diagram. I will tap into the LPCS wire and give that a shot. "

http://www.veryuseful.com/mustang/tech/engine/images/mustang88AC_Controls.gif

Good luck.

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