Before the converter output voltage can be checked, it is necessary to disconnect both DC output wires from the converter.
Use a 5/16 hex driver to disconnect the wires. Cover each wire with electrical tape to prevent shorts. Plug the converter into a 120 VAC source.
Using a voltmeter, check the converter output voltage.
Place the Positive + (red) probe in the POS + output (red) and place the Negative- (black) test probe into the NEG- (black) output terminal of converter.
Be sure you have good connections at the terminals. If the voltage reads 13.6 Vdc (+/- 0.2 volts), the converter is functioning properly.
If the converter output voltage reads in the 13.6 Vdc range and the battery is not charging, check for:
- an open inline fuse in the battery wire (if provided)
- an open wire between the converter and the RV battery- loose ground
- improper torques
If the converter fuses and AC voltage are good, but the converter output still reads zero volts, the converter is not functioning properly.
Contact Cheng USA, Inc. Tech Support at 1 (877) 294-8997.
You need to call them. The Blue wire is the output from the voltage converter and should be providing current to the charger circuits.
Did you meter BOTH orange 40 amp fuses? They may be hard to check visually. Remove them and using the Ohms setting make sure they are both good.
The Blue wire in your photo is the output wire from the converter and it is "good" so the problem is on the fuse board.
Can you check to see if there is 13 volts at the blue fuses?