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2nd Gen Ram Tech1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
Low pressure switch should be on top of the receiver/dryer. High pressure switch should be on the compressor itself. The pressure switch circuit gets powered from the PCM...... Should see power with engine running, and blower fan select on any position for a/c, or defrost.
If you were missing one of the switches you couldn't have put Freon in it.
What do the switches look like I’ve only been able to find the one on the dryer
The other one is on top of the compressor, It is disconnected in the pic you posted.
Power goes from the relay to both of the high and low pressure switches then to the compressor. The pcm controls the relay. If your relay clicks on and has power then follow it threw both pressure switches then to the compressor. The pressure switches are "safety's" and will cut power to the compressor if pressure is to high or to low. Who charged it and how much Freon was put in?
If you were missing one of the switches you couldn't have put Freon in it.
The other one is on top of the compressor, It is disconnected in the pic you posted.
Power goes from the relay to both of the high and low pressure switches then to the compressor. The pcm controls the relay. If your relay clicks on and has power then follow it threw both pressure switches then to the compressor. The pressure switches are "safety's" and will cut power to the compressor if pressure is to high or to low. Who charged it and how much Freon was put in?
40 lbs is what it reads when you jump the compressor
I have a 1998 dodge ram 1500 the ac compressor will not engage ac has been charged and there also isn’t any power going to the hi low pressure switch be fore I take the engine harness out and try and find a shop to fix it I was hope some of the doge guys here could help me in a last ditch effort
When the refrigerant was charged, was the system pumped down and let sit for 1/2 an hour or so to make sure it held vacuum? (Check for leaks.) I see the connector on the compressor unhooked, has it been hooked back up?
Is the pressure switch connected on the receiver/dryer? This is on the passenger side of the firewall. There is a round switch on the side of it. This is the lower pressure switch. This opens if the pressure is too low. It's a two wire switch. With the engine running and the compressor hooked up, you can jumper it with a piece of wire. Just thin mechanics wire is goof enough. Jumper the connections in the plug while the engine is running and the system is turned on. If the compressor engages, either the switch is bad or the pressure is low. The low pressure switch just screws onto the side and is activated by a ball on the dryer. It shouldn't leak so if it does, your receiver/dryer is bad.
