After changing the manifold heater and both relays I keep getting code that says power supply issue to manifold heater. Truck will not start in cold weather without block heater anymore. It never used to be so temperamental.
Stuck in colorado, part on its way in an hour. Any suggestions to help with this cold blooded truck?
The hotels really frown on plugging in at night, and I'm over the road this is so inconvenient!
I have plenty of juice and a good jump pack to keep my batteries up also so I do not believe that is the issue.
What tools should we need to change the air temp sensor? I have a good schematic to look at but it's not a manual of course! just showing it's on the top of engine about halfway back.
Thanks for any tips!
Parked in colorado

 

Common issue with the 03 when hard starting cold is the injectors. Colder weather increases the gaps in the injector body which allows fuel to flow back with resulting low rail pressure.

You need to have a return flow test done on each injector, just one bad one can cause this issue.

You can also try to re-torque your injector crossover tubes(I believe 39ft lbs), before you spend any money doing anything else. If you find a loose one you just might have found the problem

 

Exactly what code is setting? Check the wires that run under the battery tray they often break at that location. Use 12 volt test light check for power and ground at the relay on cold start up.

 

Thanks for the advice it was faulty manifold heater. Fixed cols start problem now like to fix the slogging uphill issue !
More on that on a different thread though!
Gypsy.. back on the road California bound