New Power Converter shows 3V, not 12V

[magoo2016]

We had power issues where shore power was not working for interior lights and not charging coach batteries.
Decided to upgrade electric panel to WFCO 8900 Power converter with WFCO T30 Transfer Relay.
Have attached pictures showing smaller older power converter with new power converter.
Now I am showing only 3V on the output of the converter (right side of panel). The batteries are charging up only while driving through the main batteries and the interior lights only use coach batteries and discharges coach batteries.
The 12V side of the power panel has small LED lights that are supposed to light up when voltage is available in circuit. None of them are lit up any more although I think they were lit after installation.
Have checked 40 amp reverse polarity fuses and they seem OK.
Think that the key may be that I am seeing only 3 volts on coach 12 volt side?
Any ideas?
Could it be a ground some place?

[Vicr]

Where is your negative battery lead terminated?

[magoo2016]

Will post an updated "after" install picture later.
Both the positive and negative battery terminal have a connection on right side of panel.

[Campers & Fishers]

I've had WIFCO's in a couple of RV's I've had, worked great too. Right now my RB195 has a WIFCO 3750. I suggest you get a manual for your WIFCO. Research the 12V side. I bet you will find that there two (2) fuzes on the 12V side, and the manual will explain their location. If you have changed your power panel, be sure you have terminated your ground exactly as it was on the previous panel. Good luck....

[magoo2016]

thanks for your comment.
That is what I will be doing first now that I have time.
Is it true that the LEDs on the right side of panel for 12 volt connections light up when connected properly?

[magoo2016]

Have confirmed that I am getting 12 volts at panel and have confirmed that the cables are not reversed. Checked the 2 40amp fuses on panel and they are good.
The 2 cables from battery show 12V before I plug them into panel but after plugging into panel shows 3V?
Can confirm that it is a problem within panel I guess.
will now focus on panel and12V wiring.

[Campers & Fishers]

I cannot say for sure because I'm not sure about your model, but, there is a fuse on the inside of the box on one of the printed circuit boards. The WIFCO manual for your specific model will give you the details. Good luck

[BillV]

Black pig tail wire should be in a dedicated circuit breaker (15 or 20 amp minimum). I cut black wire off beyond the pig tail.

[BillV]

Double check your two 40 amp fuses.