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Old 06-03-2014, 05:15 AM Fanatic

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Compounding Issues

So I've had this problem with the AC that I can't seem to get resolved with the basic advice received so far. I've also had a problem with the brakes whereby the pedal seems hard without much braking force.

Now, the brake light stays on for a good 4 or 5 seconds when starting. Another issue that came up this weekend was kind of odd when it first happened. While towing my boat and using cruise control, if I hit the right blinker, cruise control would deactivate. Sometime it wouldn't deactivate, but instead would cause the engine to rev up momentarily about 200 RPM (almost like the tranny was slipping). Again, these issues only occur when I use the right blinker while cruising.

Could all of these problems be pointing toward a single culprit, like a vacuum pump??
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Old 06-03-2014, 06:53 AM
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Turn signal / cruise - check / replace the third brake light in the cab roof. When this bulb is out, since the turn signals and brake lights are connected, the right turn signal sends a sneak current back to the brake pedal switch, fooling the PCM into thinking you've pressed the brake pedal. So it interrupts the cruise. Autmatic transmission? If so, this would also explain the RPM rise; phony brake pedal signal to PCM -> unlocks torque converter.

Brake warning light / hard pedal - vacuum pump or a vacuum leak somewhere, drawing down the reserve in the distro box and/or booster. This may also explain the A/C issue. Can you elaborate on what's going on with your A/C?
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Old 06-05-2014, 02:41 AM Fanatic

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Thanks madpogue. I'll check out the brake light issue. Would certainly be nice to know its that simple.

Regarding the AC issue, I could explain it, but it would be easier to point you in the direction of the other thread I had going on that issue: AC Issue
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