JINMA battery charging woes

[lohr500]

Hi all, our sailing club in the UK has a 2004 Siromer 304, which is a rebadged Jinma as far as I can tell. It is the basic 304 model with a creeper box.
The battery isn't charging. When running the main tag on the alternator reads 14.6 volts, as do all the fuses on the fusebox apart from the main batteryfeed which reads 13.2v. This matches the battery voltage when measured on the live side of the starter solenoid.
My conclusion is that the ignition switch may be faulty with an open contact or high resistance contact when in the 1st position, thus not allowing current to fully flow back to the battery. Does this sound likely before I start testing continuity etc?
Any thoughts appreciated.

Should have added that when the key is turned to the heater plug setting the ammeter reads negative and the starter engages when the key is turned further. So in those two positions current is flowing from the main feed through the switch. Would the alternator continue to push out 14.6 volts if position 1 on the key was open circuit? It is a 4 wire alternator.

 

[lej]

I have a foton 404 and it will quit charging the battery atleast once a year and the alt. output is 14.2. I found quick connect tuck in behind in the line to the battery. I lose partial connection and have to take apart and spray with crc electronic cleaner and then it will start charging.

 

[lohr500]

Cheers Lej, I'm sure it must be something similar on the Siromer. I'll be back to the sailing club on Saturday with multimeter, wire, etc to trace out where the bad connection is. The main 12v feed is taken off the live post on the starter solenoid, so I suspect the problem is somewhere between there and the live side of the electrics after the key switch.

 

[lohr500]

So after 2 hours of messing about trying to find where the dry or high resistance joint was in the wiring I gave up.
Alternator wire 4 was at 14.4 volts with the engine running. Voltage at the ammeter was 14.4 volts.
Voltage on the main starter +ve pin and battery 13.2

I figured out from wiring diagrams I found and by measuring the voltage with the engine shut down and key removed that wire 4 on the alternator is permanent live.
So in the end I connected a new wire with 30 amp in line fuse directly between the alternator and the starter +ve pin.
Bingo, battery voltage now at 14.4 volts when running.
A bit of a bodge job really, but it has solved the problem. The only downside is that the ammeter no longer moves as far as it did before. Presumably because the direct feed from alternator to battery offers a lower resistance path for the current to flow.