Quote:
Originally Posted by Fish'n John
I wonder if this connection to the ignition also may answer why I get 0V when the ignition switch is off. Since the jumper connection is only made inside the charger, the charger has to be on or I have an open circuit between the two 12v batteries. It seems to make sense to me that with the charger off I should get 0v at both locations. What I don't understand is why I get 12v when the ignition switch is on. Maybe the charger is wired internally so the 24v terminal is looking only at one 12v battery, but does it make sense to you that measured across batteries 1 and 2 with no jumper I should get 12v?
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I think what you've measured makes some sense but it's the opposite of what I think you've said above. What happens (IMO) when the ignition is on or when the charger is plugged into the AC outlet is that the charger configures itself in what I've called "charge mode". The (internal) series connection between the 2 trolling batts is opened and then all the batts, including the engine batt, are connected in parallel (+to+, -to-) and then also connected to the engines alternator output or the chargers AC/DC output. This charges (or tries to) all the batts simultaneously. Thus I'd expect you'd measure 12V at all the outputs when the ignition is on or the charger is on AC. There is no series connection between the batts to add them to make any higher voltage in this "charge mode".
Now with the AC off and the ignition off (like you'd have when trolling) the charger should reconfigure itself. The trolling batts should be isolated from the engine batt and the (internal) series connection between the 2 trolling batts should now be made. Thus the voltage across these 2 batteries adds up to the desired 24V. This last part doesn't seem to be happening. It appears the charger is coming out of "charge mode" but not fully going into "trolling mode". What's missing is that internal series connection. Thus when you measure from the 24V + terminal to the 24V - terminal you get zero volts. The circuit is open. It's the same as trying to measure the voltage between 2 AA batteries sitting on your table by putting one lead of the volt meter on one batteries - and the other lead on the other batteries +, w/o any other connection between the 2 batts. Now the question is why is this the case. If the clunk you hear is the charger solenoid trying to make it's internal serial connection then either a wire has come off, burned up ... or was taken off deliberately. Let me explain the last part.
When you had your old 12V TM, the installer might have disabled the 24V output so you couldn't blow up your TM by giving it 24V (disconnected a wire inside of the charger so even when the relay engaged it wouldn't make the serial connection to add the batts). When the new TM was added the guys at Expo North might just have kept the old wiring ... just because they didn't realize it could be changed. Thus you've been deprived all these years, running at half thrust.
If this theory is correct then you might be able to open up the charger and replace the missing connection and get your 24V back. However there are multiple other things that could be wrong. Before I can troubleshoot any further I need to understand what the connections are.
See my new diagram and see if you agree with the labels and connections to the batteries. I've shown it with the internal connections as I think they should be when the charger is operating in "trolling mode". I could have the Aux1 and Aux2 labels swapped so before we go any further perhaps you could make a few voltage measurements and settle the diagram.
With the AC not connected, the ignition switch off and all the batteries connected and the TM completely disconnected ...
Measure the voltage between Aux1 + and Aux1 -. It better be +12V. This confirms the battery is connected.
Measure the voltage between Aux2 + and Aux2 -. It better be +12V. This confirms that battery is connected. Now it gets fun.
Measure the voltage between Aux2 + and Aux1 -. I hope it's +24V. This confirms the batteries are connected in series and my labels Aux1 and 2 are proper. If it's 0 V then there's more possibilities.
Measure the voltage between Aux2 - and Aux1 +. If the above measurement was +24V then this should be 0 V. If the above measurement was 0 V then this might be -24 V. This means I've swapped the labels/meaning of Aux 1 and 2. No problemo as it still indicates the desired serial connection is being made. If it's 0 V and the above measurement was also 0 V then I can't tell much about my Aux1 and 2 labels but I'm sure the series connection isn't being made (for some reason).
BTW it's real important that the volt meter be connected "properly" to make each of the above measuements. Otherwise you'll measure - voltage when it's really + voltage. By "proper" I mean that when I say measure between "A" and "B", you put the + probe of the volt meter on "A" and the - probe of the volt meter on "B". This will be obvious when measuring across a battery. + probe on the + post and - probe on - post should get you +12V and not -12V.
Now if you're still up for more fun we can see if there's nothing missing in the other internal wiring. With the + probe of the voltmeter on "Aux1 +" terminal, put the - probe on the 12V - terminal. I hope you read +12V. If not I've probably got my Aux 1 and 2 labels swapped. If I do then stop and I'll see what makes sense to do next. If you do read +12V then continue and put the - probe on the 24V - terminal (leaving the + probe of the voltmeter on Aux1 + terminal). Again I hope to see +12V. Finally measure between the 24V + terminal and the Aux1 - terminal. I'd hope for +24V but given your prior measurements I think it'll be 0 V, same as I might expect for the above "between Aux2 + and Aux1 -" measurement. Given these results we can determine what labels are what and what's missing (if anything) for internal charger connections. See how "fun" this is ?
