Balmar Alternator Upgrade

Hi,

I am in the middle of installing a Balmar series 6 alternator with an external regulator

Is this brown wire coming out the wiring harness the ignition input for the regulator?



Also, I have no more unattached wires. How does the tach connect?

Thanks,

Bruce

Test it with a multi-meter. Test for voltage with the ignition switch on, then off. Off-topic observation - I see in the picture a number of hot wires on a post of some sort. One is much heavier than the others. The heavier wires, in succession, should be at placed at the bottom of the post, smallest at the top.

Typically, the brown wire in the balmar harness that hooks to the 4 pin connector is for the ignition signal.
The tach is usually a white wire either directly to the stator terminal on the alternator, or to the output terminal on the regulator.

I found a brown wire in the engine junction box. It was not connected. It does give me ignition switched DC voltage.

The brown wire coming out of the harness is spliced in the junction box to a wire that I can't determine the color. After it left the harness it was again spliced this time to a red wire. Here's where it attached to the original alternator. There is no voltage on this wire with the ignition on.




Is this possibly the wire for the tachometer?

Bruce

Bmarler said:

Typically, the brown wire in the balmar harness that hooks to the 4 pin connector is for the ignition signal.
The tach is usually a white wire either directly to the stator terminal on the alternator, or to the output terminal on the regulator.

Click to expand...

If you download the Balmar Alternator manual, it'll explain the brown wire. Just search on "brown" in the pdf file.

PennBruce said:

I found a brown wire in the engine junction box. It was not connected. It does give me ignition switched DC voltage.

The brown wire coming out of the harness is spliced in the junction box to a wire that I can't determine the color. After it left the harness it was again spliced this time to a red wire. Here's where it attached to the original alternator. There is no voltage on this wire with the ignition on.


View attachment 137591

Is this possibly the wire for the tachometer?

Bruce

Click to expand...

I’m not familiar with that alternator. It’s certainly possible that’s a stator output for the tach, but I don’t know for sure.
You may need to get a volt/ohm meter and some long wire and ring out the wires to be sure where they go.
Are you sure the tach you have is already driven from the alternator?

FlyWright;

The problem is not on the Balmar side. I have the manuals and they are excellent.

The problem is on the engine side. As noted above, I fixed the "brown" wire problem. The remaining issue is the tach wire. Where on the old alternator was the tach getting its signal.

Bruce

FlyWright said:

If you download the Balmar Alternator manual, it'll explain the brown wire. Just search on "brown" in the pdf file.

Click to expand...

Bmarler;

No, I am not sure. Looks like I will have to track the wire from the tach to the engine.

Bruce

Bmarler said:

......Are you sure the tach you have is already driven from the alternator?

Click to expand...

PennBruce said:

Bmarler;

No, I am not sure. Looks like I will have to track the wire from the tach to the engine.

Bruce

Click to expand...

That’s the best bet. As you noted, it’s easy enough to wire the alternator to the regulator, but properly connecting to the boats wiring can be head scratching. Like I mentioned, get a long length of wire, hook one end to that red wire in question, (unhook the red wire from the alternator first) and hook the other end to one lead from your ohm meter. Other ohm meter lead to the tach input wire. That’ll let you know if it’s the same wire.
Btw, which regulator did you get?

What's the engine? Someone else might have the same and be more familiar with the wiring.

As Bmarler suggested, I tested for continuity between the wire on the tach and the wire on the engine. It confirmed that the engine wire is the tach wire.

I reconnected and started the engine. Joy! The tach is now working.

twistedtree;

The engine is a Lehman 120, 2715E. The old alternator is a Prestolite.

Here's a photo from American Diesel Corp showing the wiring for the Prestolite.



Bruce