2002 Durango Issues

I have a couple of problems with my truck that I am kinda sure what they may be, but could use some fresh ideas that I may be overlooking.
Problem 1) Cruise control
My cruise control seems to have a problem with staying on. NO, it has nothing to do with speed. The actual cruise won't stay activated even when not in use! (indicated by the cruise light) The run down is this. I start the truck and the cruise light comes on (computer checking the system). The cruise light then goes off. This is normal. I go to hit the button to turn the cruise control on and that is where the problem starts. The cruise light comes on, then immediately goes off. Sometimes it stays on, but for only a short while. Other times, it doesn't come on at all!! I think this may be related to the cruise brake switch as I have played with it and got it to come back on steady, but that test was inconclusive as I didn't have a lot of time to fully test it out. The other issue, which I hope it isn't, yet highly doubt it is, is that my computer is messed up. Relays and fuses are all ok. Is there something else I should be looking for? Some other test I could do to narrow the possibilities? Something I have not considered?
Problem 2) A/C warm to cool
A/C seems to be a crap shoot. I have no way to test the pressure, but i see no apparent leaks. The dealer recharged it just last summer, so I doubt there is a leak. I pressed on the high pressure valve slightly when the truck was off and there was a ton of pressure. So I am going to assume the system is not leaking. Now, when the truck is cold and i start it for the first time in the day, I can turn on the A/C, and the compressor kicks on. It does NOT have intermittent on/off cycles. The appropriate lines get warm and cool but never cold or hot. After I tested this, I shut the truck off. I restarted and let it warm up. I then turned on the A/C and walla - compressor does not want to turn on. So I am thinking this is my problem... but how was it on before? I went and removed the relay switch and checked that - its fine. No fuses or broken relays. I tested pin 30 and pin 86 - both have 12 volts - 30 pin in the off position of the ignition and 86 in the on position of the ignition. I jumpered the 30 pin and 87 pin - blamo! I got a working compressor! So just to be sure, I swapped the relay with my fog lights relay - its the same exact part number. I turned it on, no compressor workie. Fog lights work fine though! Rechecked all the fuses and relays - everything is good. I am baffled! The only thing I think it may be is that my system is over or under charged. However, I wanted to test that by overriding the pressure check switch, but I couldn't find that switch. I traced out the wiring diagram and found it to be in the exact opposite place that Hayes manual stated (they said next to the fire wall and evaporator - the switch with blue, blue/black, oj wires is right next to the condenser on the return line). Needless to say, I attempted to jumper those wires to be sure that it was or wasn't the right thing - and well it wasn't. No damage to the truck or anything, but it tripped the check engine light. No biggie.
So what I am looking for is other options on what could be wrong with my A/C system and other things to look for on my cruise system. I am very car knowledgeable so speaking in savvy lingo will do me just as fine as lay-mens terms.
Thanks in advance!
Freppster
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

For the cruise , try lifting up on the brake with your toe , then try to turn the cruise control on.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I tried that, but that only works sometimes. I will conduct a complete test tonight and post my results.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ok, i checked the switch attached to the break pedal. That part is the break like switch. It made no difference to the cruise control problem. I removed it totally and still had the same problem.
Another idea I have is that the vacuum module is not working properly, which is coding it to shut down. I disconnected the battery and reconnected after 2 minutes. No odometer codes, but the check engine light did flash 10 times.
I also checked all the wires to the transmission as I have read this may also cause the cruise to turn off or not stay on at all. They all seem fine. No visible breaks in the wires and all the connections were snug.
I am baffled. Again, any help would be great! Thanks in advance!
**************
Update - A/C is working now. It was low on coolant. Thank goodness!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Freppi wrote:

If you disconnected the switch then it would look like you had the pedal depressed all the time, causing the cruise to shut off. So I'm not surprised it made no difference. Is this a manual tranny by chance? Same issue could be with the clutch pedal switch. Cruise will shut off if the computer thinks either pedal is depressed. The switches are normally open and are held closed when the pedal is not depressed. Unplugging he switches harness opens the circuit so it will appear as if the pedal is depressed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Freppi wrote:

Didja check the switch on the steering column?
JAM
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Freppi wrote:

Could be a bad brake pedal switch.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Aight... this is what I have done so far - sorry for the lack of response:
I removed the break pedal switch from the mount and held it in closed position (depressing the actuator) and still the problem has occurred.
Another test I ran was checking all the connections to the PCM and to the vacuum modulator. They seem to be in working order, clean and debris free.
In testing all these things out, I did come across a constant anomaly. When pushing the various buttons for the cruise control system, I noticed the following: If the cruise control is on and the indicator is lit, if I push the cancel button, the cruise completely shuts off. If I push the the set button, nothing happens (I am doing these tests in Park in idle) - the light remains on and the system appears to be on. If I push the coast button - it turns off completely and the indicator goes out.
Could this be then a faulty switch that is causing the issue? The results are very constant when I run this test. The only thing I question is that after driving a mile or two, the system indicator will not come on at all no matter what you do, however, it will come on at least right after you start the truck. It will also remain on for a maximum of 2 minutes and a minimum of 1 second. Another thing, in idle, I get the same result of the cruise not coming on after about 2 minutes or so... no matter what I do (with the exception of restarting the vehicle), the cruise control indicator will not come on again.
To answer previous question - it is an automatic.
Another note, I had an electric brake system installed for the purpose of towing my Camaro around. I disengaged that as well to see if it was causing an issue, but it seems it doesn't have an effect on the issue. I get the same problems with or without the electric break wired in or not.
Thanks so much to all that have responded - I really appreciate it as I used to rely on my father for electrical help with automobiles, but he passed away a year ago and now I am left to fend for myself.
*******************
AC issue is all set though - seems it was related to the system not being properly charged. I am in the process of getting that taken care of.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.