I have a 99 dodge ram v8 magnum my instument cluster stops working and the odometer says no bus the truck wont start

CAR STARTS RUNS AND DRIVES.
SO ONLY THE IP CLUSTER FAILS.
next is check all fuses, for sure to cluster. 4 fuse run it. or more. and PTC fuse 2. skip no cab or engine b ay fuses check them all first.
SPEED CONTROLS MEANS ;CRUISE DEAD
WELL LEARN THAT CRUISE WORKS ONLY IF ALL KEY THINGS WORK EVEN BRAKE LAMPS.
FORGET CRUISE TO LAST, fix this only LAST.
cruise can never work if speed is failing VSS for any reasons.

what "NO BUS" means ,I can not guess this,at all.
so odometer is dead but shows what/
blank, -------,.------,?????? or what be clear on this.
all gauges are dead, that means the IP cluster brain can noT communicate.
any scan tool used here OBD2 you will see what fails
it sure will but every poster here 99% fears scan tools
not sure why at all. me.?

start car now and and idle it
use DMM meter measure battery volts
13. to 15vdc is a MUST, if not alternator is dead or its fuses blow or gee both.
if true stop and fix this first or computers in the car will lie to you and go quite mad.
this test is on page 1 of all modern cars chapter electronics failing and testing
the battery must be fully charged
and a good battery
and alternator works fully. tested.
and all fuse tested good.
or as any car battery gets weak near 10vdc
any and all electronics onboard die or go crazy random acts. don't let this happen to you.
if the starter motor sounds fast and robust the battery may be ok.
but if sounds week we change it till it sounds right.
or replace it or jumper cable jump any car with a very low weak battery . to get voltages above 13vdc.

I'd have to check voltage and ground for the instrument cluster. I noticed one of the fuses for your instrument cluster goes hot with the key on, same thing for ac compressor. I'd have to voltage feed to and from ignition switch for applicable fuse. Check the ignition switch wiring connector. I can't rule out ignition switch itself, at the moment.
There could be other issues?
Ignition switch faults are common on some makes and models.
Instrument cluster wiring connector problems. Sometimes if you disconnect and reconnect the instrument cluster connector, it may start working again, also, cycling the instrument cluster connector may reset, if it starts working, well, it's working for now, may quit again.
Some instrument clusters may do a self test, don't know about yours?
Press and hold odometer reset button, turn key to run position release odometer reset button, watch the odometer. Your indicator lamps may turn on and off, the gages may cycle in small increments. The cluster will exit self test on its own.
You may have to check buss circuits.

cluster or bus wires going down, test bus voltage to cluster,if reference voltage ok to cluster then internally a cluster issue,best place to start diagnosis.

could be the ignition switch. It's definitely an electrical problem, and the ignition switch is the most likely cause.

check the speed sensor on the transmission,the wire could have been cut or the ground may have been attached to a bed bolt and it could have been overlooked.

Sounds as though you've lost a grounding point to the firewall. Check the flat uncoated braided wire that runs from the engine block to the firewall and check it for integrity.Shoud be tight and clean. Secondly if you can get your hand up behind the instument cluster try to push the main harness group in with your fingers.

you probbally popped a fuse. Check all fuses in the car and trailer. Make sure all the lights are in good condition and that the connections going to the trailer from the car are in good shape.

i am having the some problem with my 2001 dodge ram 1500 all of my gauges stop working after the engine light came on now on myodometer says no bus, Can you help me with it

All the modules are connected together to communicate with each other via the PCI bus. It is possible that one of the modules is pulling the bus down.Since the vehicle won't start it could be any one of the modules. It will be a process of elimination to find the faulty one by disconnecting them one at a time. Here are a few, powertrain control module (the one you replaced) Instrument cluster, overhead console, anti-lock brakes, airbag. Since the cluster unplugged wont read anymore, just try to start the vehicle to see if that was the one. Otherwise see if the odometer message of "no bus" goes away after each one is unplugged.

From the official Durango shop manual......(abbreviated)

Self Diagnosis Test

Vehicle key position is OFF ,or able to pull key out.
Hold in the trip odometer button (dont release yet)
Turn key to the ON position (one notch), but DON'T try to start the engine
Continue holding the trip button for about 10-12 seconds until CHEC appears in the odometer display
Release the trip button.
Series of three digit numeric failure codes may appear.
If no failure message appears, the self diagnostic test will proceed as described in step 6


Code Chart

110- cluster CPU,RAM,EEPROm failure, replace cluster

900-CCD data bus not operational, check CCD data bus connections at cluster, check the cluster fuses,check the CCD data bus bias, cehck the CCD data bus voltage, check the CCD data bus terminations.

920-cluster is not recieving a vehicle speed message from the PCM, check PCM software level and reflash if required, use the ($2500+) DRBIII scan tool to verify the vehicle speed message is being sent by the PCM

921-the cluster is not recieveing a distance pulse message from PCM,check PCM software level and reflash if required, use the ($2500+) DRBIII scan tool to verify the distance pulse message is being sent by the PCM

940-the cluster is not recieving an airbag lamp-on message from the ACM, check the CCD data bus connections at the ACM, check the ACM fuse.

950-cluster not recieving an ABS lamp-on message from the CAB, check CCD data bus connections at the ACM, check the ACM fuse.

960- clsuter not recieving a PRND21 message from the TCM, check the CCD data bus connections at the TCM, check the TCM fuse.

999-An error has been discovered, record the failure message, depress the trip odometer reset button to continue the Self-Diagnostic Test

Step 6
Instrument cluster will test each segment of the odometer (all first, then each one seperately)

Step 7
Bulb test

Step 8
Gauge test

Step 9
test completed

The instrument cluster will return to normal operation at the completion of test, if ignition switch turned off, or a vehicle speed message indicating movement recieved from the PCM on the CCD data bus.

Hope that help you or anyone else in future.