AC problem 1988 Bronco ll
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AC problem 1988 Bronco ll
Hi, I have an ac question. I own a 1988 Bronco ll with a 2.9L. The ac cycles at idle as if low on freon. Upon by-passing the low pressure switch, it still cycles on and off. When I disconnect the jumper wire, the compressor stops as it should. I don't understand why it still cycles when I by-pass the LP switch. Is there another switch somewhere? When above idle, it runs fine and air is cold. I don't have my gauges at the time, but checked with a cheap ac pressure gauge from local auto parts store and it does in fact show a little low. Thanks in advance for the help.
Dennis
Dennis
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From: Lorain County, Ohio
It should not cycle with the Low Pressure Switch bypassed.
How is your idle speed? If it drops too low, the PCM will turn off the compressor until it recovers. A flaky TPS can cause it too.
Also, poor performance at idle and good performance at speed is usually a sign of a failed fan clutch. (although low idle speed can cause the same symptoms).
Get a real set of gauges on it and post the pressures at 1500 RPM, Max AC, High Blower, with the doors open. Those cheap gauges can have you chasing your tail in no time.
How is your idle speed? If it drops too low, the PCM will turn off the compressor until it recovers. A flaky TPS can cause it too.
Also, poor performance at idle and good performance at speed is usually a sign of a failed fan clutch. (although low idle speed can cause the same symptoms).
Get a real set of gauges on it and post the pressures at 1500 RPM, Max AC, High Blower, with the doors open. Those cheap gauges can have you chasing your tail in no time.
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'88 Bronco ll ac
Sorry for the delay in responding back. I idled it up slightly and it kept the compressor running steady. Possible faulty tps and dirty throttle body make sense. I'll check them. Thanks for your help.
Bassman
Bassman
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From: Lorain County, Ohio
I'm not very familiar with the Bronco II but you should be able to run the AC, the PCM doesn't control much in the compressor clutch circuit. I think just the Wide Open Throttle relay. You'll need to look at a wiring diagram to confirm this.
You will, however, need a vacuum supply for the air handler in the cab if the doors are vacuum operated. I seem to recall they might be manual on the B-II. Can you switch between defrost, floor, panel vents, etc?
You will, however, need a vacuum supply for the air handler in the cab if the doors are vacuum operated. I seem to recall they might be manual on the B-II. Can you switch between defrost, floor, panel vents, etc?
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I'm not very familiar with the Bronco II but you should be able to run the AC, the PCM doesn't control much in the compressor clutch circuit. I think just the Wide Open Throttle relay. You'll need to look at a wiring diagram to confirm this.
You will, however, need a vacuum supply for the air handler in the cab if the doors are vacuum operated. I seem to recall they might be manual on the B-II. Can you switch between defrost, floor, panel vents, etc?
You will, however, need a vacuum supply for the air handler in the cab if the doors are vacuum operated. I seem to recall they might be manual on the B-II. Can you switch between defrost, floor, panel vents, etc?
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