A12: Check Circuit Continuity

With BT055 disconnected & relay #4 removed, measure the resistance between BT055/002 & relay socket pin 5

Is the resistance < 0.5 OHM?

Yes
Go to A13

No
Inspect connector BT055, fuse holder F7 & BT011/011 for corrosion, damage, bent or pushed back pins & repair as required. Test the system for normal operation