phatdaddy
+1y
you need to check if the clutch on the compressor is kicking in.
if it isn't there could be a multitude of problems.
1st turn the key switch to the on position, then turn the ac on ( you don't have to crank the truck,just turn the switch on.) check with a voltmeter if there is any power going to the power wire on the clutch. should be atleast 12 volts.don't check it with a test light, there doesn't have to be but maybe a couple of volts to kick the light on. the compressor has to have around 12 to kick on. IF your gettin power, check the ground wire and make sure it is grounded good.i don't really recommend this but you can make a jumper wire from the batt to the power wire on the clutch it should click and the front should jump out.(if it does the clutch is good).also check the fuse/ and for any loose wires. IF there is no power going to the compressor, check the wiring and fuses, Your ac control switch could be bad.(do the jumper wire to compressor hot wire test 1st though)
If the compressor clutch works but kicks on then right back off then you'll have to check a coupla of more things.
i'm not sure if a mazda has em but look for either 1 or 2 screw in switches in the ac lines one in each ac line(should be between the compressor and condensor under the hood)
if it does check one at a time unlpug it and make a jumper wire between the wires on the harness side and recheck to see if the compressor kicks on.
do one the hook it back up , then do the other. what this is doing is checking the high pressure and the low pressure switches.( they tell the compressor to kick off if there is too much pressure or not enough,to keep from burning the compressor up)the reason i say one at a time is so you know which one it is.IF the ac system doesn't have enough freon it won't work right and if it has too much it will freeze the lines/evaporator core in the under dash ac box) it will blow cold air for a minute and shut back off.
OK (this is easier done than said )
if the compressor is getting 12 volts and got a good ground and still won't work,after you check the pressure switches(IF it has them) then you will need to check your freon.there should be a sticker under the hood or somewhere saying how much to put in it. usually like 2 cans will work.
just go to walmart and get a R134 charge/change over kit. maybe 25 bux.
make sure you get the kind with the oil already in it, says it on the can.Comes with R134a, adapter fittings,hose. everything you need.
IF your truck had R12 get the change over, if not just get the r134a and hose kit.you can tell by looking at the charge fittings on the ac lines if they are both the same size it is r12, if one is bigger than it is R134a.just follow the directions and recharge your ac, just make sure you let all the old out, like by loosing a line just loosen it don't take it off theres alot of pressure possibly there.the biggest thing is when you put it in check for leaks you can see cuase it will be oily or frozen up.
sorry for the book i work on ac systems for class 8 trucks( freightliner,volvos stuff like that)
same principle just sometimes a few diff parts.
if you are confused or need any help just let me know
Dave