odd electrical events

[DWBinc]

I am working on my 06 5500 dump.  the blower works only on high, replaced resistor, no change.  If blower is running on high, push mirror heat, blower goes off.  When blower is running on high, daytime light in dashboard lights up, but if you apply the hand brake, the light goes out.  The light also goes out if the blower is set on any speed but high.  Mirror heat does not seem to be working, no light will stay on when button is pushed.  

 

I have just purchased this vehicle recently, former owner did not give me a heads up on these issues.  

[C/K Man]

Body control module?  Was the truck in a flood?

[davester]

I would suggest first checking where power is getting to and not getting to, as well as making sure everything has good grounds before buying a bcm and getting it programmed at a dealer.  Subscribe to the full-service manual for the truck at sites like alldatadiy.com, or buy the paper version at sites like helminc.com, ebay/amazon (for the paper version.

[DWBinc]

Thanks for the input guys.  I do not see any evidence of the truck being in a flood.  I will try to get a wiring diagram and check for grounding issues.  the parking brake/ running lights indicator smells like a ground issue.  Note:  vehicle has 50K on it.