We have a 2005 Dodge Grand Caravan 3.8 v6. Every time when you start the vehicle both the tach and speedometer needles go in unison from the left to the right and then back to the left. When it is doing this, there are no lights on the dash at all. Once the needles get back to their original position all the dash lights come back on and everything seems to be working fine, speedometer at 0 and the tach is at the correct engine speed. Not sure if this has any thing to do with it or not but this just started happening the last time we used our trailer and the trailer harness. And has not changed since. We checked the front control module and that is good. We are looking for other ideas? HELP??

Another separate issue we are having is we use to have great heat at 68 degrees last winter and now I have to keep moving the temperature up, up sometimes way up. I noticed it last spring. Now we are back to winter again. Is the themostat going bad? Or is there something else to check? My husband does not want to change it if it is not the thermostat. Is there a way to check the themostat or the electronic controls?

 

You can check the IOD fuse in the PDC, The trailer harness could have something to do with the cluster. On the t-stat, The t-stat maybe stuck open and that's why you need to keep turning up the heat. Replace the t-stat. They don't cost that much.

 

Your wacky gauges are often the first sign of a weak battery. Verify the connections are clean and tight then have it load tested at most parts stores for free. Feel the upper rad hose. Now start the engine and let it run 10 minutes then feel the upper radiator hose again. It should be fairly hot and hard if the t-stat opened. Verify the heater hoses are also hot.

 

Ok thanks! Yes we found some corrosion on one of the cables. we cleaned it up and put battery protector on it. Have not checked the load on it yet will do that next. But still no lights and wacky gauges everytime we start the van.

Changed the t stat. The rad hose is not real hot. The heater hoses are not extremely hot. The heat is set at HI and the out put is warm. We are thinking the water pump? Your thoughts?