Hi I’ve pulled my batteries out of my old machine without noting where the 2 x small wires with 20 amp fuses were fitted. I’ve reconnected one to the positive and the 2nd I’ve left. Does anyone know what these power and if the 2nd one goes to positive or negative. I can’t trace them as they are spliced into the main power harness. I’m pretty sure the one connected goes to the starting circuit as Key on disconnected gives me no power. cheers
First off, What Kind of Machine, Who's manufacture, what year, etc etc. Can make no determinations off a Battery photo.
Well at least we know it's yellow so that narrows it down a bit, not a Terex!
Iirrespective of the above (as necessary as it may be to know) from your photo it's clear you have a 24 volt system - two 12v batteries connected in series. So the question is what are those "two small wires with 20A fuses connected to..? Music radio, comms radio, or something similar.? Once you know what they supply then you need to look at the back of each unit (2 wires so I'm assuming two separate units) and check what supply voltage each one requires. Once you have the answer to that question it will be possible to determine to which battery positive post each one fused supply wire needs to be connected.
May be a stupid question but why did you replace the batteries? Just curious if the problem was there before the batteries were replaced. Don't laugh I have seen crazier things done in the past! Does this machine have a master disconnect switch? As Nige asked, any idea what those two 20 amp fused wires run? I'm guessing it is something added on and not originally installed when machine was new. If so, what looks like it has been added? If one added thing is say a radio can you use a tester, ohm meter or such to figure out which one is which? Say if the "new" item is a radio, connect one lead of a tester from the fuse holder at the battery and the other lead to the input wire at the battery. If no continuity switch lead to the other fuse holder at the battery. Then do the same from ignition/start switch to see if you can find the reason why no power to that switch. Also check for wires at the starter and maybe take a picture of that area.
Good point. I guess another question is that the batteries are connected for 24v in the photo but is the machine system actually 24v..?
Leave the accessory wires disconnected for now and take notice of what doesn't work. Sounds like your ignition doesn't work with one of them disconnected. Or, maybe unrelated. Take a visual of the ignition switch to see if someone did a harness overlay to bypass some bad wiring. Probability some additional work lamps or a radio that was installed at some point like Nige mentioned.
Most connections I have seen like those are 12 volt.
Apologies for the initial lack of details. Machine is ‘95 Samsung SE210-2 Yes it is yellow, new and shiny as I’ve restored it so full respray. It’s definitely 24v with a converter behind the seat for 12v fixtures. I pulled the batteries to treat the rust which was bad in the battery bay due to water sitting in there with plugged up drain holes and I’m assuming battery acid over the years. It has main isolator under radiators, if that’s what you mean by ‘master disconnect switch’? None of the wiring has been tampered with, its all clean with harnesses in tact. The 2 wires run into the harness and are not additions. All electrics on the machine work with the exception of the hyd oil temp gauge... that’s the next job. The only reason the ignition didn’t work was the thicker of the 2 small wires wasn’t connected, that’s why I figured it was associated with the starting circuit. I found a loose cluster of fittings down the side of the battery bay where one is for the old fuel pump, one of the fittings had a yellow wire same as wire in question, I got continuity with it so appears this must be an ancillary power source, but what for I don’t know. Anyway problem solvered I guess, seeing as everything else is working I’ll leave it disconnected. Thank you all for your insights.
That plug could also be for an electrical option your machine isnt equipped with.
I recall someone on this site trying to figure out a plug on a Cat machine and it turned out it was determined to be for the AC compressor. Thing is this was a machine with a open cab so no AC or heater!
Quite likely
THAT is the most politically correct way I have EVER heard expressed "Maybe the PO was an idiot, who hired people dumber than HIM" Hopefully, that is not the case here.