Dodge Repair: 03 Ram 2500:speedo,airbag,A.C,mirrors, bell


Question
I have a 2003 Dodge Ram 2500 4x4 Quad Cab Truck.5.7L My symptoms are: Speedometer doesn't work, airbag light is on, heated mirrors don't work and A/C not working. A bell rings on and off.
Is this a result of a blown fuse, or faulty wires or sensors.
I appreciate your help.

Answer
Hi Paula,
The issue could be fuses and one sensor, for a starting point:
The speedo signal is generated by an "output speed sensor" located on the side of the transmission at the back end of. Its two wires go the transmission control module and there the signal is combined with others and sent elsewhere specifically in this case to the instrument cluster on a digital pair of wires. Because only the speedo reading is not showing it is either that output speed sensor or one of its wires, and if those are OK then the problem is internal to the cluster speedo unit. I would check the sensor first particularly if there is any apparent malfunction in the gear shift behavior at various speeds which also need that sensor signal to shift properly.
On the air bag light, start by checking fuses 52 and 53 in the power box in the engine compartment. If both of those are fine, then it will be necessary to do a fault code readout using a diagnostic readout box at a shop to get a handle on what is wrong.
On the heated mirrors check fuses 17, 27, and 36 in the power box.
On the A/C the usual cause of not working is that the refrigerant needs to be added to. You can buy a kit for that and try adding about 12 oz. and see if that is enough to restore the charge of refrigerant to the necessary level.
On the bell ringing, I would check your owners manual and see what sorts of issues cause that to happen. Let me know of the possibilities that your find, though it may be the air bag light being "on" also caused the bell.
Let me know if you want more details.
Roland