I need some help with this old John Deere 1010

Hey patrons! I'm having a bit of a struggle with the glow plugs on this JD 1010, and I know many of you are very knowledgeable so I want to pick your brains. I'll be brief as I can, but it takes a bit of explaining, and the problem boils down to: I'm drawing too many amps through the glow plugs.

The machine was originally a 12V system with a positive ground, but it is now negative ground because the starter solenoid requires it that way. Of course, the glow plugs are just resistive heaters, so they don't care which direction the current is going. I have been controlling the plugs by just touching the wire to the positive battery post. The wire goes to all 4 plugs in parallel, and the circuit is completed through the block. Only 2 of the plugs that came with the machine worked, so I figured I would change all 4 of them. I got brand new ones, same part #6A467G11, made by Wellman. When trying to start the machine after the rebuild they worked for only a short time and then all 4 of them quit. I found they were all burnt out, open circuit when checked with an ohm meter. I was then wondering if the machine was wired to provide less than 12V to the plugs somehow, as it does have a voltage regulator on it. (However, those 2 that were working still are in spite of being given straight battery voltage for at least 2 minutes straight.). Today I went through the wiring diagrams, all the wiring, even opened up the key switch, and can confirm 100% that the plugs get straight battery voltage by design. There's no resistor hiding anywhere. The service manual says each plug should draw between 7-11 amps, around 9 amps each, so all 4 plugs together should be in the 36 amp range.

I got another set of 4 new plugs, and checked their resistance before installing they are all 0.2-0.4 ohms. So I put them in the machine, but I don't want to ruin them again.  I checked the resistance through the glow plug wire, 0.1 ohms.  Of course, the battery voltage will drop under load, so I put an amp meter on the glow plug wire and turned them on. 65 amps, about 16 amps each. I only did that for a few seconds and stopped to avoid another burn out.

This might be a case of "they don't make them like they used to."  It might also be that as the plugs get hot, their resistance will go up and the current will drop, but I don't want to risk that just yet.  So that brings me to that crazy photo.  That is 10 three ohm resistors in parallel, which if I'm not mistaken will be about 0.3 ohms.  (correct?)  That should bring the amperage down to around 30, and each resistor will only have 3 amps going through it which should be ok...?  If I burn up these resistors I don't care, but it would be nice if this would work.  So tomorrow I'm thinking I will put that in series with the glow plugs to cut the current down and protect them from the smoke monster.  

Any ideas appreciated.  I feel like I must be missing something here.  Or maybe these plugs are just junk and will need a resistor to protect them from self destruction.