Stewart warner Compartment heater help needed

[Rkrug]

Part number 19207SOCN11669898
NSN 2540-01-194-3323
I Picked up this heater at a military salvage yard of an m925 truck, i'm now trying to get it going I have the fuel pump plumbed and wired in and it is working,When I push the switch down to start the blower and fuel pump kick in and the two coil ( ceramic with wire wrapped around) heat up, but nothing ever happens no smoke or wosshing noise, there does not seem to be any fuel flowing even though the pump is working correctly, is this normal for startup? Just trying to figure out what the next step should be.
Thanks for any help

 

[cranetruck]

You have a newer version of the heaters that I'm most familiar with, but they basically work the same way.
If this is what you have, you should hear a clicking sound from the fuel valve solenoid cycling on the heater, the clicking rate is slow for "LO" mode and faster for "HI" mode.



In the picture, the fuel flow rate is measured and it's very critical for starting
(17 ml/min or 0.02 lb/min).
Note that the start process may take several minutes, that's right, several minutes. You may have smoke in 60 seconds or so, but keep holding the switch down and combustion will sustain itself, when it's hot enough, the flame switch triggers the light on the control panel. When the light comes on you flip the start switch to "RUN" position.
The "HI" mode is locked out during start, so it doesn't matter if it's in "HI" or "LO" during start.

 

[Rkrug]

Thanks for the pic and info, when working on it yesterday I found that it was not getting any fuel, I think it was because the solenoid was improperly grounded, Im going to run a grounding line to it and try again to day to see if that fixes it.

Other problem I am having is that the push to test is not working but the bulb checks good on the continuity tester, I am only getting .1-.5 volts when checking two cables of 3 going into the socket, which I am thinking are the ground and continues 24v for testing, and the other cable would be the switched leg for the light, so if I use my volt meter I should get 24v across the switched leg and ground once it fires up?

 

[cranetruck]

This is the control box wiring (ignore the notes, which pertain to the coolant heater)


The original wiring diagram has an error, which is corrected here as seen.

The push to test light tells you that you have power (24VDC) going to the heater circuitry.

 

[Rkrug]

Got it going, turned out to be a bad ground to the fuel solenoid and a bad ground to the indicator light, also replace one O ring for the fuel strainer that was leaking, every thing is working grate now.
https://www.youtube.com/watch?v=zHD2vLTCafE