No AC, Rear wiper or Instruments???

[Ensane]

I have a 1999 Dodge Caravan plain version, Recently has lost its ability to turn on the AC, the rear wipers, any guages or odometer, When you first start the Vehicle the Odometer, fuel guage and Transmission selector will light up then in about 5 seconds they will all go out and never return until the vehicle is re-started, and this is not always the case sometime dont come back when you start. Anyone with some ideas or similar problems.. have tried a new ignition switch with no success.. On a side note the Blower fan does come on but just no AC nor the light that is associated with the Snowflake button.

[RIP]

The gauges, lights, wipers, and odometer could be caused by a cranky Body Control Module (BCM). It controls all the electrical functions of the van except engine electrics and airbags. Find the IOD fuse in the Power Distribution Center (PDC) next to the battery. Pull it out for a minute and reinstall it. This will reset the BCM and hopefully convince it to cooperate.

Another thing to try is simultaniously push the trip odometer and reset buttons on the instrument cluster for a few seconds. This will put the instruments through a test and hopefully reset them.

The A/C is another story. Don't see where the BCM could affect it. First, verify the clutch is not engaging when you press the A/C button on the A/C heater control panel. Make sure the fan is on. If it's not engaging it's for one of two reasons. Low coolant level or an electrical problem in the circuit.

The number one reason A/C systems won't work is due to low coolant in the system. If you've had no experience with checking pressures, take it to a shop and have them check the system pressures and service coolant if needed. If you don't know what you're doing this system can kill you. Short of that, find someone with a set of gauges and some experience and have them check it. Low pressure side should read about 40 psi, high should read about 240 psi. That can very some due to ambient temps.

Before you make that trip verify the two fuses for the A/C are good. One is on the juction block under the dash. The other is in the PDC next to the battery.

If the system pressures are good use a multimeter or test light, push the A/C on button and check for 12VDC at the A/C compressor connector. If it's there, replace the A/C compressor clutch. If not, tap on, wiggle, reseat the A/C clutch relay on the PDC. Sometimes there is an identicle relay on the PDC. Swap the two relays. If the clutch engages buy a new relay and replace. I've got a hunch that's as far as you'll have to go. Keep in touch. There's plenty of people on the forum with A/C experience. Cheers!

[Ensane]

OK, Pulled the fuse for the Memory and nothing changed, stimutaneously held down Trip and reset on the Odometer, never did see it do anything. I am thinking that the Ac is tied to all of this somehow, the coolant level is fine, Pressures check out OK along with relays and fuses. Is there anything that ties all of these actions together? Absolutely Everything else works on the vehicles besides I might add whatever makes your venting switch from defrost, to floor or from floor to face vents. that will not change either.. Other than that the blinkers, running, tail, headlight, flashers, horn, Radio, all work without any hiccups..

[RIP]

Type "instrument cluster caravan" in the search function. There's gobs of info there. Just have to fish through it. It appears a common fix is cleaning the battery terminals and cable grounds. I've heard it said the electronics on this van are sensitive to corrosion.

[Ensane]

Update: Still have not exactly found the problem, put it on the computer to check for errors.. it did detect that Ac, wipers and cluster were having problems and all pointed to PCM (powertrain control module) we swapped this out with a known good working one and still same problem.. after further checking I did notice that when the Van is running and the key is in the "on" position nothing worked.. but if you turned the key to the start position again all of the guages and AC, and wipers would all work, as long as you held it there in the start position it would be fine.. but if you let off. then they would all go away.. Maybe this will help for some solution.. Thanks for all ur help.