I have a motor home with a Trace inverter/charger. When the unit is connected to shore power the system will recarge the battery pack fine. When they are charged the remote meter will switch from bulk charge to float charge.The problem is when we are dry docked and attemt to charge the batteries with the generator system,the charge rate stays on bulk charge mode constantly. I have had the generator checked out by a certified teck and all is good there.The only places in my area that service invertors is a marina and they want me to send them just the invertor.I would like to have it tested in the coach as there may be a problem in the coach as well. Can anybody give me some advise

don't know the system, but it should be easy enough to trace it with a simple voltmeter. I would suspect the battery connections first. A bad connection could allow the battery to charge and the converter could provide enough power, but when off, the voltage drop across the battery terminal could be too much.
Without shore power, turn something on that will draw a few amps and measure the 12V starting on the battery connection, not the battery terminals. Then compare it to a measurement on the terminals. If there is any diff, remove the connectors, clean and lub and replace. From there, just follow the wiring.

no statement at all its use;. sure a BOAT, got you there,
how is this inverter connected on both ends.
one end is DC other is AC out. right>?
12vdc input (the big red/black wires) not reversed nor fuse blow, to these pair.
the output is a large AC power jack pure sign wave AC power. it does, means can run computers and things that hate cheap chopper type inverters.

why did you say connected to shore power(AC)
that is not its purpose or job ever. that.
its purpose is to convert, DC battery power to AC POWER
at up to 1200VA (watts)
that is about enough power to run a toaster.(almost)

do not ever connect shore 120VAC power to that large connector on the front of this inverter or you will blow it straight to H3LL
and worse a fire.
the jack there is marked OUTPUT, so connecting short AC output to inverter output is super wrong and dangerous.
I can tell you shore power will win the bucking war here,
boom fuse blows, fire, and smoke can happen., and will. 1 or all 3.

answer 2: connected right (per makers web site see it)?
battery main boat not dead or just disharged. 12.6vdc is good, less bad.
AC jack output on inverter works with say a desk lamp 120VAC 100watts , if not the inverter fuses blow or bad inverter.
some you can hear it sing, ear to casing. (inverter oscillator inside)

have the unit checked by an authorized generator repair shop
if it was operating when shore power came back on there is every possibility that the generator or inverter has been damaged from the lack of synchronization of the sine wave

although it is possible to do separately most times the transfer switch is internal to the inverter , and the fact you mention that inverter is not charging batteries tells me your fault lay in the inverter all or part of it is not working , look at it carefully these have sometimes two reset breakers on there cases

If a normal install, the shore power and generator will go through a transfer switch then to the inverter. If when inverting 120 VAC circuits are OK, then the problem must be before the inverter. I would suspect that it is the transfer switch.

Disconnect shore power, make sure generator in NOT running then take a look at the transfer switch these are in a boat or RV but either can lead to vibration problems which can lead to loosening wire connections which can lead to heating and burning. It may be something as simple as a wire coming loose. (Which could be dangerous!)
Whether or not the contacts in the relays are OK, check and/or tighten all electrical connections. It's a good idea to check and tighten all electrical connections regularly.

Some transfer switches can be repaired by replacing just the relays. Other units (like mine this year!) will need to be replaced entirely.

It sound like unit is in inverter mode. You should read user manual because those chargers/inverters could be very difficult to setup right

the solar panel is just to charge your inverter,if it is charging and the inverter is on it will drain the current the solar panel is supplying to the batteries,this makes it look like it is not charging ,so i advice you to switch off you inverter when charging it,get another set of batteries connected to your solar panel then charge both, let them be separated so that the new one is not in use so that when solar is out you can switch to the other set of batteries

The fan can be replaced. It is very similar to some of the PC cooling fans. I've got the same problem (again) and will be replacing it soon. I will give you the fan specs once I remove my fan ( I think it is 4" 120VAC - will let you know when I repair mine).

How are the batteries for that inverter? Have you got a dead battery in the loop?

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c

If you are referring to a Trace 2412 inverter, which series is it? An SW or a DR series? In either case, if it won't accept generator power, but the AC input indicator is flashing, the problem is most likely the generator output power is off frequency or voltage. Trace inverters will only connect when the AC input is within certain limits. I'd suggest checking the frequency and voltage output of the generator. If it won't connect to shore power, check the voltage from that source. Make the voltage checks at the inverter input terminals.