A/C runs and cools. Used to be able to use some climate button and get heat. Now not able to change modes on climate module. Off button does not work--A/C runs and cools all the time. Removed module and cleaned contacts as per a YouTube video. Did not fix the problem. Also cold air blows with climate module disconnected. Maybe asociated --when runing car with A/C on for an hour or so--I get a "light show"on the dash and engine may run rough or stalls. Can not restart--but if I wait about a half hour it will fire up right . Two year old battery and I use a tender. 12.7 V at battery with engine off-even after no start.

 

Not being an expert on the climate control systems I would suggest you speak with Bryan at Batee.Com. He rebuild's the C68 electronic air conditioning controllers. Bryan is an expert in the AC control systems of the C4's and the "Guru" of Digital Dashboards. He is a true asset to our community!

When I was rebuilding my dashboard Bryan suggested that I do the C68 at the same time. Great advice! The components used in the dash and the C68 were both designed with a 15 year life expectancy and this means replacing some components on the PC boards but not that hard to do.

On your battery, you might want to give it a serious charge with a regular battery charger of say maybe 10 amps or so. Batteries on tenders tend to stratify the electrolyte and this makes for a reduced capacity in your battery. Another test you should do just to eliminate the possibility is to measure the output of the alternator in Alternating Current (AC). There should not be any AC ripple or anything AC coming from the alternator. AC can do some serious damage to the electronics if it gets to them. Fortunately the battery acts like a large filter and removes a lot of it.

Just to eliminate it from the list of possibilities measure the output of the Coolant Temperature Sensor and verify that it is accurate. The resistance value cross reference chart is in the FSM and it will tell you the approximate temperature based on the signal. A bad CTS can drive your ECM crazy as it has an effect on many, many decisions the ECM makes.

Good luck and let us know what you find so we can all learn a bit more!

 

Try simply removing it and reinstalling

sometimes the pin connectors develop an oxidation on them , not allowing good contact.

-or- if lazy and dont want to pull the module out

try pushing really hard across the face (not the buttons but the other surfaces) to push it in slightly deeper.

sometimes that will make it start working also

 

Hi DizWiz24

Thnaks--I only pulled it in but did not reistal to see if the buttons worked. I'll recheck all the internal and external PINS. do you think the no start is linked to the malfunctioning climate controller? The no start has never happened in cool weather --just 90+ days when running.

 

I discovered on removing controller again that the middle button between Fan speed butoons was jamed . Opened unit up again and noticed I must have overtightened one of the two screws holing down the PCB (the one with the contacts). The female screw hole was cracked and restricting the button. I removed the craked corner. On reassymbly there was enough remaining in the screw hole for the screw to bite (got lucky!!). l pugged head in and all buttons functioned!! . Now I have constant cooling. For removal and contact cleaning --I followed Ozzstar Car on You Tube ---Thnaks Glen!! No I have to takemit out tommorow on a long ride to see it the stallign problem has been resolved. Keeping my fingers crossed because it only happens in the hot weather with the AC runing on rides of 50 mile or more in previous condition (A/C compressor truning on and off --Cold adn Warm air--not all butrons working--then rough engine with no start until waiting 30 minutes.

I wil also follow CTMCClOSKEY's advice and fully charge battery with a 10 Amp charger and not soley relying on my battery tender plus check if there is an AC ripple or current coming from the Alterantor.

Thanks Forum Friends!!