I need HELP

[Ricky Harper]

So I’ve got a 95 Chevrolet c1500 pickup. I just put a new engine in it like two months ago. I have been trying to get the ac working since it’s over 100 degrees where I live. I bypassed the pressure clutch switch with paper clip and the clutch kicked on. So I got get a new switch thinking that will fix it with a can of Freon. Only used one can. While I was putting the Freon in the clutch started turning but it didn’t stay turning. It would cut on and off repeatedly. So I go pull the ac relay fuse out from under the hood and thinking I might have a bad relay. I did the paper clip thing again but I didn’t turn off the truck so it made a small spark and the clutch stopped turning all together. So I went in the truck and turned the fan and ac off. I found out that since the spark when I turn the fan on it automatically turns the ac off. And the there isn’t hardly any air flow coming out of vents but you can hear the fan cut on. If the fan is off the ac is on and the clutch is short cycling but will not stay on when I turn the fan on. I need helppppp. Did I short out the blower motor relay or what? 

[Jsdirt]

One can ain't gonna cut it. Standard cab is 32 oz. (2.66 cans). Crew cab is 36 oz.  Hopefully that can didn't have an oil charge in it, either, because now you'll have an overcharge of oil, resulting in less than stellar cooling.

 

Short cycling is a dead ringer for lack of refrigerant. Also, running it that way is a good way to fry the compressor to a cinder. It's just like a 2-stroke engine without premix - whenever there's a low refrigerant charge, the oil does not get moved around. It'll usually puddle up in the evaporator, while the compressor sends shards of metal through the entire system, requiring replacement of anything that cannot be flushed (condenser, drier/accumulator, orifice tube or expansion valve (TXV - n/a in this application), and obviously the compressor.

[Ricky Harper]

Thanks for the insight. So should I try to put another can in it?? When I put the first the pressure was maxed out on the gauge. And what do you think could be the problem with my fan and ac not running at the same time?

[Jsdirt]

No problem.

 

Definitely needs at LEAST another can - probably another can, and over half a 3rd can.

 

If the pressure was maxed ... did you vacuum the system before adding the can? If not, that's why. You need to charge an empty or previously leaky system into a vacuum. If it won't hold vacuum, you need to fix the leaks first.

 

As far as the blower motor cutting out whenever the clutch is engaged, that immediately screams "bad ground" to me.

 

[Ricky Harper]

Ok thank you for the help. I think I’m in over my head with this situation. I was trying to save money instead of spending hundreds to get it working. But I don’t think I’d be able to figure it out. 

[Jsdirt]

If you have a test light, connect one end to battery ground, and the other end to the blower motor ground when the fan is on - if it lights the test light, you've got a bad ground. Easy to make it good again - either find the point where it attaches to the frame or chassis, or run a new wire straight to the frame or chassis.

 

A/C work is really very simple, but you really should have a set of gauges (high and low side), and a vacuum pump to do it right. Air and moisture are 2 sure ways to destroy an A/C system. Both need to be purged via vacuum.