| Author | Message | ||
| DGS (Dgs)
Junior Member Username: Dgs Post Number: 76 Registered: 5-2003 |
The solid "wire" is an ammonia filled tube, running to the evaporator under the dash to sample the temperature there. The thermostat is a temperature controlled switch, not a potentiometer. It operates the compressor relay primary coil. It should read "open" (infinity ohms) and should click closed (zero ohms) as you move the knob upwards (presuming the temperature probe is around room temp). The #2 knob is a potentiometer, and controls the fan speed (through a big transistor). The transistor is mounted up by the evaporator so the aircon will keep it cool. (Slick, eh?). The switch position on #2 enables the aircon. You can bypass the thermostat using a fuse, but be careful not to ice up your evaporator, as the compressor will run solidly whenever the #2 knob is out of the zero (switched off) position. The replacement thermostat Fiat supplies under the Ferrari part number (61931100) doesn't _quite_ fit the console, and would leave the knob "zero" position pointing the wrong way. I did a search on the numbers stamped on the original (3ART5RF46), and found it on the G.E. Industrial web site. http://www.geindustrial.com/cwc/products?pnlid=4&id=3art5t&SMSESSION=NO It came from a coke machine.  Really. (Well, a "beverage cooler", in non-brand specific speak.) You should be able to order it from any refrigeration supply house. I thought it was a bit weird to run a temperature "feeler" from the console up to the evaporator, so I've been whomping up an electronic replacement that uses a remote thermistor. It can also use the WOT signal from the throttle switch to shut off the compressor under full throttle. My first version didn't test well, as the relay pulled more power than expected. I have the redesign on the breadboard, but getting it onto a printed circuit has been superceeded by getting the ignition computer fixed or replaced. | ||
| david handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1022 Registered: 5-2001 |
Don't know, but mine was intermittent in operation. I got a small metric Allen wrench (1.5mm, I think) and removed the knob and flushed it with electrical contact cleaner around the shaft. Worked it back and forth, and then repeated several times. Works fine now. The symptons I was experiencing was the compressor not kicking in. | ||
| Carmine Nicoletta (Ncarmine)
Junior Member Username: Ncarmine Post Number: 100 Registered: 6-2002 |
I need help with the 328 AC thermostat switch on the center console (No. 3 in Figure). Tere are two contacts and a solid ~12gage bare wire at the back of this switch.
Needless to say, I'm trying to troubleshoot and AC issue. Thanks  |