Bee utey, I need some input please

[It'sNotWorthComplaining!]

A while back I asked about a problem we had on a BA falcon with an impco system that wouldn't start on gas. Recently everything stopped even petrol starting stopped until I hot wired a lead to the pump.
I have pulled the LPG circuitry out from under the dash.
There is a Lean bias processor and another gizmo to time the switchover.
I've taken a couple of pics When petrol is selected the petrol light comes on the gizmo,when switching to LPG the lean light on the bias processor lights , and the R/Rev for a second. There is another LED called ON never lights up. So my assumption is it is not getting +voltage??? And the 2 relays ,only one clicks, the other doesn't at any time, I swapped them for working relays and no different.

pic 1 switch on petrol only start
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pic 2 Switching to gas key on, if not cranked the light extinguish after about 2 seconds
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pic 3.Cranking engine with switch to lpg, the R/Rev light extinguishes very quickly
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pic 4 the back of the Lean bias processor, it doesn't appear to be clipped into the harness, unless its been fused into the harness under all the tape.
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any advice appreciated.
thanks

[Roverlord off road spares]

?//
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[bee utey]

pic 1 normal

pic 2 normal, safety cut-out function for stalled engine.

pic 3 normal, "r/rev" is richening on revving up, is only an indication of the TPS voltage being registered.

pic 4 "on open loop" light means it's set for rich idle, the box should have an adjustment somewhere to set the TPS input where the controller starts working. If it's set to zero your idle mixture is controlled and the light will stay off.

I would check all earthing points for gas solenoids, especially the one on the gas tank. Often they are earthed to a bit of thin metal under the vehicle without any waterproofing. All earthing screws should go through two layers of tin or through a section of chassis. Cover the screw and terminal with neutral cure sealant. All other joiners should be soldered and heat shrinked. Get someone to operate the starter for a second or two, put your finger on the main gas lockoff valve under the bonnet, and the one in the tank control box. Both should click on with cranking. If gas valves click then check for gas line pressure under the bonnet with the engine off, two spanners and slightly loosen the pipes on the main gas lockoff valve.

Dunno about the relays, one may be a fuel gauge changeover. I don't usually use Peel stuff, it always looks a bit amateur made to me. I prefer water resistant electronics where I can see them, under the bonnet.

[It'sNotWorthComplaining!]

thanks that give me something to play with over the W/E

[bee utey]

Thinking about it the other box with the million-wire-plug is more likely a problem. Read Roverlord's doc and you will see it cuts the fuel pump too (join the two fuel pump wires and your fuel pump will run as normal). Also pin 5 green lpg lock will be the one that runs the gas solenoids. Put a test light on the green wire for checking gas solenoid output on cranking. Check the whole connector for signs of melting and discolouring. If the box is cactus you may need to purchase another.