Diagnosing dual tank balance module

[MrMarty51]

I was replying to the above
THEFERMANATOR
post about what controls the secondary pump since that was the discussion. Sorry

Not a problem. I was only suggesting starting a new thread as this one was last posted to in 2019.
A new thread with a new member signed up always gets a lot more attention than an old thread.
Didnt mean any harm in any way.

 

[Will L.]

Use it like this to send a note to him

@THEFERMANATOR

 

[THEFERMANATOR]

Does the PCM also control the secondary pump in a 2003 8.1L Gas C4500? I can't find the module

Yes, it is a completely different system than the balance module system. Both tank level units go to the PCM, it converts each tanks reading into 1 total reading and sends that signal out to the fuel gauge, it also controls the transfer pump operation.

 

[TN454k3500]

I know this is an old thread, but has been super helpful. I have a 1997 K3500 7.4L dually, only has 64k original miles

The fuel gauge/transfer tank has been an issue. The first post by Matt was exactly what I needed.

I've done all the checks, but when the balance module turns the transfer tank pump on the fuse blows (when I ground out the solenoid to turn the pump on....). If I remove the transfer pump out of the circuit and put my volt meeting on the plug I get a constant 12.5-13V. This tells me something with the transfer pump is bad, is this correct?

Front tank level reads ~96 ohms when full
Rear tank level reads ~125 ohms when full - Hasn't been emptied in a while.....

 

[MrMarty51]

If the fuse fails to burn out with the pump disconnected then, be My guess, there is a shorted feed wire between the connector and the pump or, the pump motor is shorted internally.