73 merc 140 one wire alternator charging ??

[pillsy]

1973 merc 140. One wire alternator. It shows 14.5V at the back of the alternator while at idle. and around 12.70-12.80 at the battery posts. this system goes througt the ammeter, instruments, accessories, ignition, starter then battery. The ammeter shows in the positive. This is with no load like blower and lights. seems low to me. My jeep cherokee charges battery at 13.5V at idle at the battery. I have heard it should bat 1.5 volts above the battery voltage. Any info would help. THANKS!

 

[Eric 3.7LX Alpha 1]

Re: 73 merc 140 one wire alternator charging ??

what are you gettin for voltage at the instrument panel. seems like corrosion on terminals somewhere or wiring has too much resistance to battery

 

[pillsy]

Re: 73 merc 140 one wire alternator charging ??

Just went out and checked. still 14.5 at alt. It's about 13.40 at the instruments, including ignition and ammeter. The guy that owned it before me did some funky wiring from a fuse panel to alot of the instruments. they are all the same color wires, it looks like a rats nest. Checked both sides of the fuses there are about 6 of them. All but two were the same 13.40 on both sides. The two that were different were showing about 9/10.5 volts on one side and 13.40 on the other.

 

[pillsy]

Re: 73 merc 140 one wire alternator charging ??

Battery + Terminals are all new.

 

[pillsy]

Re: 73 merc 140 one wire alternator charging ??

Just went out and checked. still 14.5 at alt. It's about 13.40 at the instruments, including ignition and ammeter. I guy that owned it before me did some funky wiring from a fuse panel to alot of the instruments. they are all the same color wires, it looks like a rats nest. Checked both sides of the fuses there are about 6 of them. All but two were the same 13.40 on both sides. The two that were different were showing about 9/10.5 volts on one side and 13.40 on the other.