# 1947 8N Junction Block or Resistor Block?



## Bigfoot365 (Sep 27, 2006)

I am restoring a 1947 model 8N (S/N in the 27000 range) and I'm a little confused by the electrical system info in the FO-4 shop manual. I rescued the tractor from a field rusting away, and the wiring had fallen apart. The voltage regulator was rusted beyond recognition, and there was a junction block on the opposite side.

I purchased an 8N10505B regulator that was listed for use by my S/N range, and I noticed that the Resistor Block was also listed for my S/N range so I purchased that as well. I have no idea if the tractor originally came with the junction block rather than the resistor block - which should I use?

The FO-4 manual shows the resistor block for early 8N's but also indicates a cutout rather than the voltage regulator. The manual only shows the junction block used with the newer side mount distributor models.

Any suggestions?


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## Fordfarm (Dec 27, 2005)

For the early 8N, you should have a resistor block (A8NN12250A). It goes right under the Amp guage. This is still a 6 volt system? Do you have the I&T F-04 manual? There is a helpful wire diagram on page 119. This manual is available at TSC and stores like that. It's a great thing to have. Let us know!
Welcome aboard!


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## Bigfoot365 (Sep 27, 2006)

Thanks for the reply. I do have the FO-4 manual but I am confused because that diagram shows a BONN10505A Cut-out for use with the resistor block. This is still a 6V system.

As I mentioned in my previous post the tractor definitely had a voltage regulator and junction block, not the cutout and resistor block. Of course who knows when the parts might have been replaced, but they look original. The generator is the older 3 brush type and the distributor is front-mounted, so something does not gel with the FO-4 manual information.

The voltage regulator (8N 10505B) that I purchased from Just8ns.com is listed as "Voltage Regulator 8N Before 263844" so it would seem to be correct for my machine as well. Should I try to return the regulator and buy a cutout for use with the resistor block, or just use the 10505B regulator with the junction block that was on the tractor when I started?


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## Fordfarm (Dec 27, 2005)

I use the Voltage Regulator with the resister block shown in the diagram. I'd make sure you have the correct resistor block to go with the VR you got from Just8ns. I bought my resistor and VR at TSC. Been vorking fine for years, now! You just might have to start from scratch, since you don't know what was done to the tractor. Another suggestion - get a new wire harness from TSC or Just8ns. It will save you LOTS of heartache in the future! Good Luck!


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