68 Autotemp diagnosis

[Stephen Richins]

any one on have any pointers and or insight on diagnostics for the autotemp all I know is its mostly controlled by vacuum switches & check valves. The fan works but nothing else seems to work

 

[Davea Lux]

If nothing works, that usually means the control is not getting vacuum to it. Check the branch fitting on the intake manifold to see if the small line coming off it is attached. If it is attached, remove the small vacuum line from the fitting and see if is open. Those small tubes sometimes get clogged with carbon. Next, check the push button control for leaks, usually if it is leaking bad enough to disable all functions, the control will hiss from the escaping vacuum. These systems were prone to lots of vacuum leaks and were not very reliable, but start with those two checks.

Dave

 

[Stephen Richins]

If nothing works, that usually means the control is not getting vacuum to it. Check the branch fitting on the intake manifold to see if the small line coming off it is attached. If it is attached, remove the small vacuum line from the fitting and see if is open. Those small tubes sometimes get clogged with carbon. Next, check the push button control for leaks, usually if it is leaking bad enough to disable all functions, the control will hiss from the escaping vacuum. These systems were prone to lots of vacuum leaks and were not very reliable, but start with those two checks.

Dave

thanks if it happens to be the control buttons are they fixable or do you have to find a used one?

 

[Davea Lux]

thanks if it happens to be the control buttons are they fixable or do you have to find a used one?

The cartridge in the push button control unit is replaceable and replacements show up from time to time on E-Bay. The factory did not try to rebuild the units, but in some cases they can be repaired, it depends on what is causing the leak. If the cartridge case is broken, the unit is usually junk and would need to be replaced. There is another control unit inside the right kick panel. If that is defective, there are no replacement units anywhere. If you do not already have a copy, download the FSM at www.mymopar.com, you will find the manuals in the tools/reference section, this has a good description of the various component parts of the ATC system. Most folks today convert the factory ATC system to a manual system by scavenging a parts car as there are few good fixes for the early and very unreliable ATC system.

Dave

 

[WorkerBee]

There's some good info here.

 

[LeBaron1973]

This would be another challenge for our architect friend Javier as he's already straightened the 'unstraightenable" bumpers on his New Yorker, and repaired his ATC system.

 

[MOVE N UP]

Entering the 9 circles of hell... trying to resurrect my ATC... update IT LIVES!