Power Source Battery or Alternator?

[Solex 27]

I am now in the process of wiring the head lights and tail lights on the 308-8 that is now running off a Magnum 12. The Wheel horse drawings all reference powering these lights from the engine alternator. Limited research  suggests that wiring the lights from a battery source seems to be the more popular method. Can you tell me the advantages of this method?  I am just running bulb tail lights and stock headlights.

[slammer302 2,156]

i think it keeps the brightness of the lights more stable if you run off the alternator the lights will dim more when the engine is at lower speeeds

[gwest_ca-(File Mod) 11,393]

You have to run the lights to match the engine's charging system. Does the M12 have a voltage regulator? If in doubt post the engine's spec number.

Garry

[Solex 27]

Gerry:
Difficult to read, but the spec number appears to be 471527, the first 3 digits of the serial number are 240. The last two might be 72.

[gwest_ca-(File Mod) 11,393]

Your engine was made in 1994 so it would have ended up on a 1994 or 1995 312-8 tractor. Here is a wiring diagram showing the 15 amp regulator.
http://www.wheelhorseforum.com/files/file/3823-tractor-1994-312-8-wiring-detailed-492-4509pdf/

The 1994 and 1995 models used a 116338 ignition switch which is different than the 111215 replaced by 103991 used on the 308-8. I do not know the difference in them nor can I find it yet.

For comparison
1986 308-8 wiring
http://www.wheelhorseforum.com/files/file/1836-tractor-1986-300-series-om-wiringpdf/
1987-1988 308-8 wiring
http://www.wheelhorseforum.com/files/file/241-tractor-1987-300-series-om-wiringpdf/

Garry

[gwest_ca-(File Mod) 11,393]

Found the switch descriptions
You should be OK with the 308-8 switch. Connect the lights to the A terminal which already powers the hourmeter if you have one of them. Should add an appropriate fuse for the light circuit also. The lights on the 312-8 use a 15 amp fuse.

Garry

Edited June 24, 2015 by gwest_ca

[Solex 27]

Garry, Thank You for your help here you are a real expert. I just want to make sure that I understand the drawing. 
1. Connect the wire from the motor regulator to the A terminal on the Key switch?
2. Connect the wire from the seat switch to a 15 amp fuse and then on to the light switch?
3. Where did you find that information on the Magnum?
 

[gwest_ca-(File Mod) 11,393]

Garry, Thank You for your help here you are a real expert. I just want to make sure that I understand the drawing. 
1. Connect the wire from the motor regulator to the A terminal on the Key switch?
No. Connect the DC+ wire from the regulator to the R terminal on the ignition switch. You should have a white wire in that position now but it was designed for 3 amps so the wire is not likely heavy enough. I would replace it with a 14 gauge white wire and that way it will match the 312-8 diagrams.

2. Connect the wire from the seat switch to a 15 amp fuse and then on to the light switch?
No. The seat switch has nothing to do with the lights. Do not apply any power to the seat switch wiring. That will cook your ignition coil because the ignition is self-powered. The ignition switch and seat switch simply ground the ignition coil to shut it off. Connect the light fuse to the ignition switch A terminal (Accessories) and then to the light switch. If you have an hourmeter it will already be connected to the A terminal.
If you need to change the terminals or add wires to the connector on the ignition switch do you know how to remove them from the connector?

All this applies to the 103991 switch above.

3. Where did you find that information on the Magnum?
The Kohler serial numbers are in a page near the front of the Kohler engine service manuals. Here is that page
http://www.wheelhorseforum.com/files/file/1108-engine-kohler-dating-engines-by-serial-number-1965-95pdf/

or
http://www.wheelhorseforum.com/files/file/250-engine-kohler-dating-engines-by-serial-number-1990-2007pdf/


To find out where the engine was used I went here
https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro
Click on Advanced Search
In Engine/Motor model type in M12S-471527 (That is the engine numbers you gave us)
Click on Submit on the right side of the page.
All the models that come up used that engine.

Garry
 

 

Edited June 25, 2015 by gwest_ca

[Solex 27]

OK Garry, I don't have an understanding of how this circuit works. However I should be able to wire the switches per your instructions add a fuse. The key switch is already wired  and I don't need an extraction tool to remove pins from the connector. It is long gone and  it uses individual AMP Faston terminals that are mated to the tabs on the key switch.

Thanks for the help.
 

[gwest_ca-(File Mod) 11,393]

You can get a replacement harness for the 5-pin ignition switch from places like Napa. Someone mentioned here that the wires can be removed and reinstalled in a different location so the wire colors match better - good idea. Any I have used I cut the wires at different lengths so all the butt connectors don't end up in the same place. Slide a couple of shrink sleeves on each wire, solder the connection, shrink the sleeves and it is good as new.
Here is the one Stens has
https://www.bantasaw.com/catalog/viewproduct.asp?i=205&p=1326

Garry

[Solex 27]

That universal wiring harness is a bargain, I have spent more than that on wire and terminals. I have a c series  to do next and will use this part to replace all the 1979 wiring.

[Solex 27]

Working tail and headlights, electrical all done. I just need to put the wheels on and  cut the grass. Many Thanks.