Heater and AC no workie

ok i have an 87 6 cyl 5spd. Like the subject says my ac and my heater dont work. however the blower,i think thats what its called, does work. So when i turn the air on it does blow air thru the vents. If i turn it to heat air only comes out of the defroster vents, also when i turn the ac on the aux fan doesnt come on. Any ideas of what to check and go through. I dont wanna take it in, and the only thing ill take it in for is to get the system drained and recharged. So any ideas would be helpful.

Possible vacuum leak. Check connections going to the "Hindenburg" (that blimp looking vacuum canister) which is mounted on the inside of the front bumper on the passenger side. The plastic tubing going to that thing tend to get brittle and break or get eaten away by battery corrosion.

ok i found out that when the heater is on air doesnt come out of the defrosters it comes out of the rear passenger vents and the front seat vents that are by the feet area. I will have to go check the "hindenburg" also what type of refrigerant do older xjs use??

87CherokeeChief said:

ok i found out that when the heater is on air doesnt come out of the defrosters it comes out of the rear passenger vents and the front seat vents that are by the feet area. I will have to go check the "hindenburg" also what type of refrigerant do older xjs use??

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You have two different problem, heat first, if the mixer settings on the dash work, in other words, you can redirect the air from the defroster vents to the dash vents and then to the floor vents that sounds OK. If the system only blows cold or slightly warm air then you need to look at the mixing valve on the heater hoses in the engine compartment.
Number two problem.
The AC takes R12. If the system is low the compressor will not come on, if it has air in it then it will not take a charge. You need to draw a vacum, shut the vac pump off and see how long it holds a vacumn. Should hold for *at least* 30 minutes. It is also recommended that you replace the bottle looking dryer tower whenever the system is opened to the outside. Once you have a vac on the system it will take a charge.

RichP said:

You have two different problem, heat first, if the mixer settings on the dash work, in other words, you can redirect the air from the defroster vents to the dash vents and then to the floor vents that sounds OK. If the system only blows cold or slightly warm air then you need to look at the mixing valve on the heater hoses in the engine compartment.
Number two problem.
The AC takes R12. If the system is low the compressor will not come on, if it has air in it then it will not take a charge. You need to draw a vacum, shut the vac pump off and see how long it holds a vacumn. Should hold for *at least* 30 minutes. It is also recommended that you replace the bottle looking dryer tower whenever the system is opened to the outside. Once you have a vac on the system it will take a charge.

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Yes i can direct where the air goes, so the mixer works. As for cold and warm, i dont notice a difference when its on heat compared to AC it feels the same to me. is the fact the compressor may not be working directly related to the fact the aux fan doesnt work? i thought that as soon as i turn the dial to AC there was some sort of relay that turned the fan on? or am i wrong and the compressor is what actually turn the aux fan on. Where is this mixing valve you speak of? and how would i adjust it?

how do i tell if the compressor is working? and can i go to some auto store and get a checking/charging bottle that has the guage on it? And the vacuum thing your talking about, is that something i would need a shop to do??

Also, all the hoses under the hood seem fine. One of the hoses from the compressor is in seemingly ok condition but some sort of insulation? hose is sorta rotted off.

87CherokeeChief said:

Yes i can direct where the air goes, so the mixer works. As for cold and warm, i dont notice a difference when its on heat compared to AC it feels the same to me. is the fact the compressor may not be working directly related to the fact the aux fan doesnt work? i thought that as soon as i turn the dial to AC there was some sort of relay that turned the fan on? or am i wrong and the compressor is what actually turn the aux fan on. Where is this mixing valve you speak of? and how would i adjust it?

how do i tell if the compressor is working? and can i go to some auto store and get a checking/charging bottle that has the guage on it? And the vacuum thing your talking about, is that something i would need a shop to do??

Also, all the hoses under the hood seem fine. One of the hoses from the compressor is in seemingly ok condition but some sort of insulation? hose is sorta rotted off.

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You're going back to 87 so I'm just using knowledge I have from working on others of that genre. The mixing valve is in the engine compartment, passenger side, all the heater hoses go into it and it has a kind of lever on it, when you turn the temp control from cold to hot it opens that valve up and allows hot coolant into the heater core, when you turn it cold it turns the valve off and stops coolant from entering and flowing thru the core, it uses a cable I think. The factory ones from my understanding are plastic and break with age. I'm not saying it's ancient but consider it is almost old enough to vote The replacments are metal, $15 or $30 comes to mind at AA...
The other thing if the valve is working is that the core may be plugged with crud. There is a link somewhere on backflushing it or blowing it out with a garden hose but not too high pressure. You'll have to look for it.
As for the aux fan, it is tied into the A/C compressor ckt, when the A/C compressor cyles 'ON' it turns the fan on, when the compressor cycles 'OFF' the fan turns off within a few seconds. On the OBD II systems like my 98 has the compressor and fan are turned on by the computer which operates the relays and monitors the high and low pressure sensors in the drying tower and on the high pressure side near the compressor.
I'd get the heat working first then once thats all done I'd tackle the A/C, might as well do a 134A conversion, it will be cheaper but you really do need to pull a vacumn on the A/C system before recharging it after you have found and fixed any leaks or you are just going to have to either recharge it constantly or go thru the whole repair process over again. Also the oils in the two, R12 and R134 are not compatible so part of the vac draw is that the old R12 PAG oil gets removed and then replaced when it recharges with the correct R134a pag oil. Drawing a vac may not remove all the pag oil from the system, specifically the drying tower which has a drying agent in it. I'd fix what I could and let an A/C shop handle the rest...

ok well its late now, but i will try that first thing in the morning after i get up. Thanks a lot for your help Rich. Ill keep ya posted.