1990 Dual Force 120s one side showing 16.7v at speed with dual batteries

[dingbat]

On your Force outboard?

Voltage regulators are simple generic circuits. Schematic is studied in electronics 101

VR dissipate excess voltage as heat. The issue is getting a unit large enough to dissipate the output as “heat” w/o melting. The 35 amp charging system on my 200 hp uses a water cooled regulator.

You could install the VR from a Ford pickup that would work on your Force Outboard

 

[gica]

Voltage regulators are simple generic circuits. Schematic is studied in electronics 101

VR dissipate excess voltage as heat. The issue is getting a unit large enough to dissipate the output as “heat” w/o melting. The 35 amp charging system on my 200 hp uses a water cooled regulator.

You could install the VR from a Ford pickup that would work on your Force Outboard

Can you give me a part number for reference and is it the 4 or 5 connectors? Also I assume that this won't handle the deep cycle batyeries either. The ones I looked at on eBay have one positive conector and one stator plus ground and ignition.
How do you connect the 2 stator and tach. Tach can actually go on the stator wire right?
YesterdayI bought a Mercury MERCURY MARINER OUTBOARD VOLTAGE REGULATOR 815279-4 (Q66) 20amp. It's a 4 wire.
Let me know on the Ford please. Thanks

 

[Jiggz]

Can you give me a part number for reference and is it the 4 or 5 connectors? Also I assume that this won't handle the deep cycle batyeries either. The ones I looked at on eBay have one positive conector and one stator plus ground and ignition.
How do you connect the 2 stator and tach. Tach can actually go on the stator wire right?
YesterdayI bought a Mercury MERCURY MARINER OUTBOARD VOLTAGE REGULATOR 815279-4 (Q66) 20amp. It's a 4 wire.
Let me know on the Ford please. Thanks

This should work for you. Note the gray wire is not a negative wire but most likely for tach connections. The body is the negative connection, meaning it should be grounded properly. Note some people mounts this with the epoxy side against the engine block while others put the aluminum side against the block. The aluminum side is also a heat sink for the unit. Putting it against the block makes sense except that when the engine is running, the engine block also gets hot mitigating heat dissipation. So putting the epoxy side against the block makes more sense except now heat dissipation is only thru air instead of metal to metal. Using heat sink fins will improve heat dissipation.

 

[gica]

This should work for you. Note the gray wire is not a negative wire but most likely for tach connections. The body is the negative connection, meaning it should be grounded properly. Note some people mounts this with the epoxy side against the engine block while others put the aluminum side against the block. The aluminum side is also a heat sink for the unit. Putting it against the block makes sense except that when the engine is running, the engine block also gets hot mitigating heat dissipation. So putting the epoxy side against the block makes more sense except now heat dissipation is only thru air instead of metal to metal. Using heat sink fins will improve heat dissipation.

I got to look for some pc procesor fan heat sink maybe with the fan attached to cool it. Imagine? I think it needs 5v not 12 could be wrong

 

[topgun3690]

I mounted the new VR in the same spot as the original rectifier.....which is on the starter bracket which is out away from the engine block, so not directly in contact with the block heat.....which really doesn't get that hot anyway. Not sure how the rectifier on your Force 120 is mounted but it may be mounted the same? I put some heat transfer paste on the back of the VR before mounting it. Been on there several years with no issues......FYI

 

[gica]

I mounted the new VR in the same spot as the original rectifier.....which is on the starter bracket which is out away from the engine block, so not directly in contact with the block heat.....which really doesn't get that hot anyway. Not sure how the rectifier on your Force 120 is mounted but it may be mounted the same? I put some heat transfer paste on the back of the VR before mounting it. Been on there several years with no issues......FYI

I included some pictures on the previous page but it is mounted the same way as yours. Except it is with the epoxy towards the motor. The heat paste is a good idea I thought of that aswell.
I am sure my main problem was with the batteries even though only starboard motor showed overcharging.

 

[Jiggz]

I got to look for some pc procesor fan heat sink maybe with the fan attached to cool it. Imagine? I think it needs 5v not 12 could be wrong

No need for a fan. In fact, not even with heat sink, although that'll be nice. Try mounting it first like the Port side and then test. During test run, after about 5 minutes of WOT and charging accordingly, turn off motor, remove cowling and feel (aluminum backing) if the VR is getting hot. Hot means you cannot put your bare hand on it for more than 5 seconds. Very hot is like 3 seconds.

 

[gica]

No need for a fan. In fact, not even with heat sink, although that'll be nice. Try mounting it first like the Port side and then test. During test run, after about 5 minutes of WOT and charging accordingly, turn off motor, remove cowling and feel (aluminum backing) if the VR is getting hot. Hot means you cannot put your bare hand on it for more than 5 seconds. Very hot is like 3 seconds.

The spot it goes on is right by the starter on the port side. I will test the temp with a laser tester when I take it on water again hopefully this weekend.