I have a 98 ranger that I have jumped both sensors on and I cant get the compressor to engage. I jumped from battery to compressor to fill the sytem so I know the compressor works. I get 12-13 volts at one of the sensor when i jump it and on the other i get some crazy number like 120 and up with the number never settling. On the compressor plug I get the same weird readings. I have checked all the fuses and relays and i am not sure where to check next. I dont have a wiring diagram yet as i just bought the truck, I usually can figure it out with that , at least see where I am getting voltage coming from. Does anyone have any ideas where to check next? Thanks

 

How much refridgerant did you put in the system? Turn on the defrost and see if the compressor kicks in. It should it is a place to start.

 

Obviously U haven't read any PSI's and UR telling us U filled it. All this means nothing. Put gauges on it an tell us something useful. Without useful info from gauges U and we know nothing. It won't turn on if the PSI to begin is wrong. U need pro help. Just my view but it is heading toward hot times and what UR getting sux.

 

For reference, HERE is diagram of your '98 Ranger A/C system components.

There is an A/C clutch control relay - and at least one associated fuse - located in the Engine Fuse/Relay Box under the hood. It's possible that you smoked something when you ran power directly to the compressor clutch.

You can get a PDF copy of your '98 Ranger Owner Manual from the Ford site which will have diagrams for both fuse/relay boxes (inside cab and under the hood).

 

I used a gauge from with the color coding on it, its all i have. I jumped the compressor thinking it was to low to kick on then i put 4 cans in it which i know now is to much, but it took it, lol it was reading dead center of the blue about 40 psi and blowing ice cold air, when i took it off i hooked the compressor back up and it still didnt come on. I rechecked all fuses and relays, all good. Should i get the 14 volts at both sensors when i jump them and then that passes on through to the compressor plug? And thanks for the links to diagram and manual.

 

Was the system empty when you started? Did you repair or replace anything in the system that you had to break the system open for? Lets start at the begining in this. Why were you adding the R134a? Give us some full details of the symptoms and we can try to give some more defined help.

 

I bought the truck with a bad motor, the a/c was supposed to have worked.I never broke the system when i swapped motors. When i got the truck running the ac didnt work so i started dumping cans i it thinking it was low.The compressor never engaged is why i put the freon in it.

 

AKA, you never did your homework on how to service an AC system. Its not as simple as adding AC refrigerant. You need a manifold gauge set to monitor the high and low side pressures, to see if you are even low in the first place, and to make sure you add the correct amount.

Do yourself a favor, at the very least get a book on the subject of servicing an AC system, and then get yourself a manifold gauge set.

 

Have you checked the fuses and the relay going to the A/C clutch? What diagnoistics have you performed and what results did that lead to? We are not trying to be difficult but there are things some of us do everyday that is so common place to us that is hard to jump in the middle of a problem and give inteligent suggestions. We are there for you and let us know what all is going on.

 

When I bought the truck the lady i bought it from said it worked but no way to test. I finally go the motor in i checked it and it didnt work. I jumped the compressor to fill it. I assumed the a/c was empty so i put freon to it. I never opened the system

 

I would start by switching the A/C clutch relay with another one in the power distribution box just like it. If the truck sat up for a while it could be something as simple as corrosion in the electrodes. Once that is done jump the switch on the accumulator and see if it will kick in. Let us know what you find from there.

 

I switched relays out with several different ones. I also jumped the cycling switch. still no go. I am assuming the pressure switch runs behind the cycling switch? I am getting the same voltage as the battery at the cycling switch but when i check the pressure switch after jumping the cycling switch I get weird high voltage readings.

 

CLICK HERE to view the relevant schematic (from a '98 Ford Manual).

 

thanks for the schematic, now i can trace wiring. you came through again !