98 ram 1500 4x4 reg cab, 8ft bed, 5 speed manual.

Ac worked perfect last year after it needed charged. Once it was filled, it held a charge and worked all of last year, and I used it alot.

This year took the truck from PA to FL no issues at all other than a wining rearend (which I still have to look into), got to FL, and the AC doesnt work.

Took it to a AC repair shop that is well known for quality work and was wold that there was no freon or charge in the system and that there was dye everywhere once he used his little detection light.

My testing has found I am not getting power to the AC. I took of the main power to the AC and there isnt even a volt of power there.

I have a few questions on this.

1. What would normally need replaced on this year truck to possibly resolve this without replacing everything.

2. why is there no power even on the main source, I know the low charge safty switch is probably stepping in so the compressor wont turn on, BUT should there not be power somewhere on either of those 2 paired wires, the 2 wires going to the compressor and the other 2 going the safty shutoff switch.

There is power at the fuse box and the fuse was good.

The controls in the dash seem to work perfectly fine as it will still cycle through all of the settings and put the air in the desired vent and the temperature selection as HOT is HOT and cold is now current outside fan temp.

Nothing on the AC side of the truck was touched.

I did replace the radiator this late winter as the previous owner left 90% water in the system and it froze and bent the rad to **** and such so I replaced the WHOLE cooling system.

Would this have caused anything to bend or break on the inside like the evaporator or anything. The tech asked me if I smelled anything funky every on the inside and I HAVENT, so. I am a bit at a loss here.

Any help would be great. Truck runs great other than the AC which I want to work as it used to work AWESOME and was extremely COLD when running perfect.

 

Did you check the relay when you checked the fuse? maybe switch it with another system that is working. The evap core has the A/C refrigerant that flows through it, the trucks coolant system doesn't flow to the evap core just the heater core. The freezing water could damage the heater core though, just fyi.

 

If the system is low, no, the compressor won't run, and you won't see power on either wire going to the compressor. Compressor gets power from the A/C relay in the PDC, that, in turn, is controlled by the low/high pressure switch circuit.

With a/c selected, fan on at least low, you *should* be seeing power to at least the low pressure switch, just nothing after that.

Need to find out what seal blew, and fix that first though.

 

You have a leak! If you fill the system it will happen again in time. You need to find the leak and fix it. The low pressure switch(no freon) will stop the compressor form coming on.

 

I grabbed a leak light kit and cant see anything anywhere inside or out at any connection point.....

I did not check the relay.

Also should something going to the compressor have atleast 12v of power....whether its the LPS or the main power....?

 

I *think* the pressure test circuit is only five, or eight volts, compressor will only have power when the relay is engaged.

 

Pull the wires off your pressure switches and see if you have continuity threw both of them. Check the low pressure switch first, If you have a low charge it will not allow power threw it. You need power from the relay and threw both of the switches before it gets to the compressor.

 

What happened to;

Did you clean everything up?

 

I didnt clean anything, and still didnt see anything after I used the light.

I havent charged this yet with one of this 134a refill/dye cans to try to see where its leaking yet.

I will do this tonight or tomorrow.

 

That kind of doesn't jell with the report of dye everywhere, does it...
It was everywhere and now there is no sign... strange.