I own a 1993 Cobra Monterrey 30. I purchased it a little more than a month ago. For the first couple weeks. There appeared to be no issues with the Dash A/C. While on a trip last week, I noticed the A/C was not working. Initial troubleshooting determined that the clutch on the compressor was not engaging. Using a volt meter. I drtetermined there was no current going to the clutch solenoid to engage it. As fter checking all fuses, and relays I believed it was the low pressure sensor causing the compressor not to turn on. I bypassed the shutoff, and engaged the clutch using an external 12v source. With the clutch engaged, I was still unable to get the system to take any additional refrigerant. While the compressor was running, the air coming through the vents was also the same temperature as the outside air. I'm not sure what I should look at next. Any help would be appreciated.

When you try charging the system while it is running (jumping the low pressure switch) Put your can of R34A in a pail of hot water, from a house faucet. Open the low side gage fitting and it will go into the system (refrigerant can up) Once you have enough refrigerant it will run on its own without the jumper.Brian

What are your gauge readings while jumping the clutch?

Bikeboy57 wrote:What are your gauge readings while jumping the clutch?Which gauge are you referring to? If you're referring to the gauge on the r134 dispenser hose, it reads nothing when the trigger is pulled to dispense the refrigerant. As soon as I release the trigger, it jumps up to 150psi. It's the same result as before I realized the clutch was not engaging, and the compressor wasn't running.

For AC work there is something called a Manifold Gage Set, Two gauges, Two valves and 3 hosesTwo of the hoses connect to the HIGH and LOW pressure ports on your A/C system..THe fittings will NOT connect to the wrong hose.The 3rd hose to a tank of Refrigerant, and then the two valves decide if you pump high pressure refrigerant into the tank or if the tank feeds into the low pressure side.These are the gauges.Link to Amazon catalog pageYou can also get a single (Low side) gauge it is much less expensive and nearly as informative as the full set in most cases (But not all)

If it's all the way empty, it will show zero until it has some pressure in the system. it's possible it had a leak and the dealer topped it off and it lasted a month till it all ran out. Evaporator coils are bad about leaking.

Dash A/C issue | Good Sam Community

25 Replies

jyrostng
Explorer
Jul 01, 2017
If it's all the way empty, it will show zero until it has some pressure in the system. it's possible it had a leak and the dealer topped it off and it lasted a month till it all ran out. Evaporator coils are bad about leaking.
wa8yxm
Explorer III
Jul 01, 2017
For AC work there is something called a Manifold Gage Set, Two gauges, Two valves and 3 hoses

Two of the hoses connect to the HIGH and LOW pressure ports on your A/C system..THe fittings will NOT connect to the wrong hose.

The 3rd hose to a tank of Refrigerant, and then the two valves decide if you pump high pressure refrigerant into the tank or if the tank feeds into the low pressure side.

These are the gauges.

Link to Amazon catalog page

You can also get a single (Low side) gauge it is much less expensive and nearly as informative as the full set in most cases (But not all)
Shifty_P
Explorer
Jul 01, 2017
Bikeboy57 wrote:
What are your gauge readings while jumping the clutch?

Which gauge are you referring to? If you're referring to the gauge on the r134 dispenser hose, it reads nothing when the trigger is pulled to dispense the refrigerant. As soon as I release the trigger, it jumps up to 150psi. It's the same result as before I realized the clutch was not engaging, and the compressor wasn't running.
Bikeboy57
Explorer
Jul 01, 2017
What are your gauge readings while jumping the clutch?
Cobra21
Explorer
Jul 01, 2017
When you try charging the system while it is running (jumping the low pressure switch) Put your can of R34A in a pail of hot water, from a house faucet. Open the low side gage fitting and it will go into the system (refrigerant can up) Once you have enough refrigerant it will run on its own without the jumper.
Brian

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Dash A/C issue

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