Air conditioning problem

[Vigri]

Hi,

I have a little question.

When I drive with automatic air conditioning on, one relay makes a click after every 15-20 second. The click seems to come from dashboard and it results in a sudden power loss for instance (also lights go dull for instance). What could be the cause for this problem?

A little overview of the car is in following forum:
http://www.maseratiforum.co.uk/Vigri%27s...554/tm.htm 

Regards,
Vigri

[Thorsten Ruge]

Of course, it can be either the aircon relay or the fan relay. Both fans should be always enabled during aircon's operation.
Go into the online manual and look for those relays, then clean them seriously, do not forget to clean out the socket connectors as well! If this doesn't help you got an electrical problem or pressure trouble around the aircon, post back here again.

One more thing I did read at your description: Replace original catalyst converter with high flow one (I failed MOT before winter because to high CO concentration)
You do not need to do that man, for MOT only you run the car hot first, closed by their facility turn down CO-value at the Weber ignition comp., stop adjusting it just before idle goes critically down, then disable the hot air sensor in the plenum by pulling the plug and bridge the plug by a U-cable, only if you don't pass, disable the water temp sensor the same way as well. The car runs very crabby under those conditions, stay away from accelerating it fast, drive pretty much on idle++ through their testing station. "Hobble" away from them to the next parking lot and put everything back into working order.

[Vigri]

Thanks for the advice, I'll check the relays on weekend.
Regarding the catalyst converter, I already have replaced it and after that I passed MOT with flying colors. Because I also run it on track sometimes, replacing original catalyst was my intention from beginning.

[Thorsten Ruge]

Welcome Vigri, by the way:
Are you absolutely positive on a relay sound closed to the dash, and not the solenoid clutch, engaging all 20secs the compression unit in front? Is the aircon still cooling? This would mean you run low on R12 or 134a. Clean the relays first and then check on that. If this is the reason and alternator power drops dull on clutch engagement, the alternator's brushes might stick depending on corrosion during the long hibernation in their mounting adapters.  So, take a small metal hammer and knock carefully from all sides on the alternators housing to settle the brushes,- I say and mean carefully Dude!
After that remove and clean all alternator connections and plugs to and from the voltage regulator as well, whatever type of alternator you run presently, it might show different from the manual. The wrong or loose v-belt of the alternator causes the same problem.
Post back in case you need to top off the aircon.

[Vigri]

I tried sourcing out the problem today but with little success.
I tried to find out which ones are the aircon and fan relays but I couldn’t find out for definite. So I cleaned contacts of all the relays I could find inside dashboard (4 on the fuse box and 3 behind wooden trim just left from glove compartment). But that didn’t solve the problem and more I think the more I doubt that the “tick” I hear is from some relay.
The “tick” seems to come from somewhere inside the dashboard between driver and co driver side and it’s volume varies a lot, sometimes it’s really loud but sometimes you can hardly hear it. One weird thing is also that this “tick” mostly occurs when driving, when I stop the car and let it idle on standstill this tick goes away after few minutes, therefore it’s hard to sort out where it’s coming form.
I’m almost definite that the “tick” comes from inside the car, not from under the hood. Also the air conditioning works without problems, cooling the car as needed.

[H2o]

The ticking is normal.
It starts when the aircondition has reached the on the display set temperature. Right?
The regulation starts to switch on and off to keep the temperature on the same level.
So don't try to stop the ticking.

I also think that the cause of your problem is a bad contact, which is not able to handle the needed current. This can result to your short power loss.

[Thorsten Ruge]

Since this leaves the problem with the thermal circuit breaker itself only, bad luck Vigri! This guy is nearly not accessible without "Armaturenbrettrausreissen", sits as I remember electronically in line with the pressure switches, i.e. handling the 12V loop directly. Your assumed relay would have been easier to resolve.
But to prevent arcing combined with more serious power drops in the future you should really check on this contact.
If you wanna find out more, bridge the compressor directly by a cable to the battery and look whether the power still drops if the clutch engages. If not its for sure around the thermo switch and its connectors.

[Vigri]

It is ticking even when I turn the temperature to low so it would continuously blow cold air, so Thorsten’s variant seems more likely. It seems I have to live with the problem at the moment and try to sort it out over the winter when I’m not using the car.

[Thorsten Ruge]

And I am still thinking it’s the f…… Freon Relay before the min/max pressure switches,- try to locate it again and replace this sucker first to see whether it solves your Tick, may be the socket bottom pins are cracked behind the cable connector into the relay’s base plate:

[IMG]http//img375.imageshack.us/img375/5500/419p.th.gif[/IMG] 

If its one of the sensors, yes, Armaturenbrettrausreissen will be angesaacht for the upcoming winter my friend:

 
 

[Vigri]

Any ideas of where this Freon relay could be located? I tried searching electrical diagrams that are on Enrico’s page but with little success. Those electrical diagrams don’t seem to have that relay on them.