630 Wiring

[ancomcabs]

The manual for mu 630 shows a couple of fuses in the instrument panel. When I pull the panel off there are a couple pairs of wires with spade type connectors not connected to anything that I suspect should be connected to the missing fuses but they don't specify the size of the fuses, any idea on how I could find this out or even determine what the wires are for? The hour meter does not work even though there are 12 volts getting to the back of the meter with the key on. The lights all work, the engine warning light works, not sure about the transmission warning light and the starter/key switch works as well. The battery is also not keeping a charge, or draining somehow when I leave it for a few days, batter is almost new and the motor starts right away after I charge it. Thanks Andy

 

[Tazza]

I used 10A fuses, i checked the wiring and worked out it was rated at 15a so it was more than covered.

 

[ancomcabs]

I used 10A fuses, i checked the wiring and worked out it was rated at 15a so it was more than covered.

Thanks Tazza, dug deeper and found a better wiring diagram, seems some of the unused wiring may just be for accessories not installed (back up alarm, etc) Any clue where I should start to look to see why the battery is discharging when nothing is left on? Andy

 

[donald73d]

Thanks Tazza, dug deeper and found a better wiring diagram, seems some of the unused wiring may just be for accessories not installed (back up alarm, etc) Any clue where I should start to look to see why the battery is discharging when nothing is left on? Andy

How about you have the sense and excite wires reversed on the alternator. That will do it. But engine will run and charge fine. But alternator will have power to the excite all the time. Before starting the engine in the morning, feel the alternator, if its warm, then what I suggest is the problem.

 

[ancomcabs]

How about you have the sense and excite wires reversed on the alternator. That will do it. But engine will run and charge fine. But alternator will have power to the excite all the time. Before starting the engine in the morning, feel the alternator, if its warm, then what I suggest is the problem.

I was thinking my next step would be to start at the alternator and check the wiring. Not sure what you mean by "exite" though, the 630 has wires from the alternator (Stator) to a rectifier and a regulator

 

[donald73d]

I was thinking my next step would be to start at the alternator and check the wiring. Not sure what you mean by "exite" though, the 630 has wires from the alternator (Stator) to a rectifier and a regulator

With a normal alternator the excite wire provides voltage to the field windings. Once the alternator is putting out current, it then produces the voltage for the field windings. The rectifier and voltage regulator you are talking about are related to controlling the voltage to the field windings. As the battery becomes fully charged or the headlights are turned on, the regulator can adjust the voltage to the field windings to produce the proper output needed from the alternator. The diodes that convert the alternator output (AC) to DC are in a diode bridge inside the alternator and there are 6 diodes in the bridge as the alternator produces 3 phase AC. Once can look at the output with a scope and determine if one of the diodes is broken. The rectifier/diode you mention probably just insures voltage flows only one way. For more info: http://en.wikipedia.org/wiki/Alternator

 

[ancomcabs]

With a normal alternator the excite wire provides voltage to the field windings. Once the alternator is putting out current, it then produces the voltage for the field windings. The rectifier and voltage regulator you are talking about are related to controlling the voltage to the field windings. As the battery becomes fully charged or the headlights are turned on, the regulator can adjust the voltage to the field windings to produce the proper output needed from the alternator. The diodes that convert the alternator output (AC) to DC are in a diode bridge inside the alternator and there are 6 diodes in the bridge as the alternator produces 3 phase AC. Once can look at the output with a scope and determine if one of the diodes is broken. The rectifier/diode you mention probably just insures voltage flows only one way. For more info: http://en.wikipedia.org/wiki/Alternator

Thanks great explanation