Locating vacuum leak for cruise/ac issues?

I've read somewheres that sometimes there are vacuum leak issues that will affect your cruise control and also the air conditioning, both problems I have with my truck. The guy that had the truck before me had said the a/c slowly dwindled away but I can't recall talking about the cruise control issues with him.

Thing is, how do you go about locating a potential vacuum leak that might be related to these issues, I have looked superficially at the lines etc that route over under the battery compartment but its really hard to tell if they are good or bad...seem ok :confused:

The cruise light will come on but not engage. The AC is just marginally cooler than surrounding air temp, not enough to do any kind of cooling of the interior (especially since its all black...lol)

Any ideas welcome!

Update:
Inspected the small vacuum line that connects with speed servo and there was a small area where it had rubbed on the intake manifold housing enough to breach the tubing, I snipped that 2 inch section off and reinserted tube into the t-fitting. Also noticed a large hose unattached at the back of the manifold cover and put that back on. All of this did not help though, took it for a run and still no cruise. After pushing the on/off button on the steering wheel a few times, the CRUISE indicator light refused to come back on. I thought maybe I had popped a fuse, but after shutting off ignition back home and starting again (the second test run) the light lit up again for the first time I pressed it and then again went out. Really weird stuff...

I disconnected the vacuum line at the cruise control servo and verified there is vacuum there with my fingertip, so I guess the culprit may be the cruise control servo motor itself. Seems a little tough to track one of these down though, looked a various online suppliers with no luck, the few I did find don't ship to Canada, or if they do the shipping is more than the part!!

Has the air conditioning improved?

Has the air conditioning improved?

Nope, no change in a/c, I did jump the contacts in the fuse box to see if the compressor worked ( for it wasn't kicking in at all) and it did, but maybe its just gotten low of refrigerant over the years..I don't have any a/c gauges to check the pressures.

Was thinking of getting one of the cans to recharge the system.

Some of those install kits have a gauge on them.

Thing is, how do you go about locating a potential vacuum leak that might be related to these issues, I have looked superficially at the lines etc that route over under the battery compartment but its really hard to tell if they are good or bad...seem ok

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I usually blow some cigar smoke into the tubing and check for leaks.

Some of those install kits have a gauge on them.
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Yeah, "You can be an A/C pro too!"

I usually blow some cigar smoke into the tubing and check for leaks.


That's what I miss most since I quit smoking, a good cigar.

Yeah, "You can be an A/C pro too!"


I'm game, what's your angle?

www.acprocold.com
As seen on TV.

Ive heard of guys spraying brake cleaner or carb cleaner around on the hoses and check if it revs up the engine, if it does then thats teh hose that leaks. Ive never done it, but, hear about it allthe time. I usually just inspect the lines, broken lines are pretty obvious. Sucking vacum lines are also pretty obvious, they make a hissing sound. I would figure out how the vac ties into the ac and the cruise, and follow those lines.

Maybe on an old 350 Chevy but most of todays engines are more complex with more hard to reach hoses,ports,fittings and valves than ever before. Ya gotta pull alot off crap off to access things and feeling around a hot engine ain't no fun. Alot of times hoses crack and split as they get handled. Good luck trying to hear it unless its a major leak. Use the brake cleaner to pinpoint a leak after you narrowed it down to an area. JMHO

Does the air from the ac/heater blow at the base of the windshield/defrost, regardless of where you set it to blow?

Well cancel that, the Mode Control and Blend Door/temperature control are operated by electric actuators on an '03.

Here's an '03 FSM to open. Be sure your antivirus is on full. I didn't get any notices from my Norton.
http://www.ossh.com/dodge/03DRM.pdf

Since there is vacuum at the speed control servo motor under the battery compartment, this would seem to indicate the servo is toast? Is there any way to test this device or a backyard fix for them? I have looked online for the part to get an idea of price, but have only found it on sites that don't deliver to my address (North Bay, ON). Which is just.as well since shipping is usually the prohibitive portion of those kind of deals anyways...
Once again having no luck with any Canadian online autoparts sites. :(

Well cancel that, the Mode Control and Blend Door/temperature control are operated by electric actuators on an '03.

Thanks for that info Chris, so I can look elsewhere for my ac issue then. My blower directs air whereever I select. From all reading been doing, I suspect its just a case of the system having low pressure, for I can jump start the compressor, just gonna save up for some manifold gauges and a vacuum pump and check the system out.
Must be coincidence that ac and the cruise are gone on fritz..?

I've detected vacuum leaks successfully using the spray parts cleaner method. Its amazing how just a small leak causes the engine to idle higher. You might try measuring the vacuum on the line to the cruise servo with a vacuum gauge on some kind of T-fitting with the line connected then disconnected and plugged. If there is a great difference there is probably an internal leak in the servo.
I have ordered many parts from rockauto.com and they usually have the lowest prices, most complete inventory, and they do ship internationally (from the US).
Also, the AC compressor will not usually engage if the refrigerant pressure s too low. There are low cost gauges sold that work like simple tire gauges. But if you add refrigerant, be careful not to add more than one can of the kind containing oil. I had too much oil in mine and the thing would cycle on and off constantly which is hard on the compressor clutch. Hope this helps.