WD 45 wiring help
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=133521
Printed Date: 09 Jun 2025 at 3:54pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: WD 45 wiring help
Posted By: BradH
Subject: WD 45 wiring help
Date Posted: 07 Jan 2017 at 10:04pm
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Hey guys, I'm back needing some help yet again. A friend and I spent the afternoon rewiring the WD 45. Installed new wires, key switch, and light switch. All went pretty well, couldn't really test the lights, mine are shot. We only had partial success though. Motor turns over good, it's getting gas, but no spark. The plugs are new, plug wires, points, and distributer are all in good shape. We think the coil may be bad though. My friend is gonna pull the coil off his tractor next week and bring it to test. The thing we're unsure about is some kind of relay we found in the mix of wires. It's in front of the gas tank, between the headlight mounts. It was held on by one of the bolts holding on the air cleaner. Looks like it was wired down to the coil? I can't remember for sure now. Tried to bypass it with no luck. Anybody know what it is? Or maybe what to do next? I'll put up a picture I tried to get of it. I appologize ahead of time for the poor quality though. That's what happens when you give a blind man a camera. Thanks, Brad   ------------- Warning! Blind man with a tractor! Head for the hills! |
Replies:
Posted By: jkoby
Date Posted: 07 Jan 2017 at 10:07pm
| Looks to me like a ballast resistor. Mine used to have one, but it was on the same side as the distributer. If that is what it is, it is needed for the coil to work properly. |
Posted By: Michael Crowe
Date Posted: 07 Jan 2017 at 10:19pm
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That's a resistor you put in the wire going to the coil when you use a 12 volt battery with 6 volt ignition system. ------------- The 14th Annual Exclusive AC Swap Meet will be held in Boonville, MO, March 7-8, 2025. See the club website for details: http://www.moacclub.com/ |
Posted By: BradH
Date Posted: 07 Jan 2017 at 11:12pm
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Awesome, Thanks. Once again you guys come through for me in the end. So my next question is how hard are they to find? Apparently I'm gonna have to get my hands on one. Thanks again, Brad ------------- Warning! Blind man with a tractor! Head for the hills! |
Posted By: Gary in Texas
Date Posted: 08 Jan 2017 at 5:28am
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Check with Steve at B&B Custom circuits. He may recommend to replace coil with correct one and forget the resister. Gary in Texas |
Posted By: jaybmiller
Date Posted: 08 Jan 2017 at 6:09am
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yup , ballast resistor With it busted(open), no power to coil = no spark = sad face. Every auto parts store will have it, should have a 1.5 Ohm value ( 1.4-1.8). It drops the 12 volts of the battery to 6 while allowing 4 amps of current to flow. Quick fix, buy another resistor.. cheap...<$5 You can then get her running, after that think about a new coil. Better( ?) fix, buy a TRUE 12 volt coil (it'll read 3 Ohms with meter) and no resistor required. Simpler wiring but costs more and not 'correct' for a 'restored' tractor. Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: LeonR2013
Date Posted: 08 Jan 2017 at 7:28am
| Use an Ohm meter and see if you are getting power thru. the resister. It may be good, so why buy another good one? |
Posted By: Sugarmaker
Date Posted: 08 Jan 2017 at 9:13am
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Brad, Are you changing the tractor to 12 volt negative ground? Regard, Chris ------------- D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet. |
Posted By: Steve in NJ
Date Posted: 08 Jan 2017 at 9:29am
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Gary in TX is right on the money. If you wired the 45' for 12V's, take that ballast resistor and throw it in the creek. Pick yourself up a 3.0 Ohm internal resisted coil for the change-over if that's what you did. If its still 6V's, that doesn't need to be in there. But it sounds to me like you converted it to 12V. If ya can't find the correct coil locally, we have em' in stock. When switching over to 12V with a 4 cylinder, you need 2.7-3.3 Ohms of resistance in the Ignition circuit. DO NOT purchase a "Universal" 12V Coil! They are only 1.8 ohms. Fine for 6 & 8 cylinders, but not 4 bangers. Visit our website. There's a lot of info there on 12V conversions... bb-customcircuits.com Steve@B&B ------------- 39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife |
Posted By: BradH
Date Posted: 08 Jan 2017 at 9:58am
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Okay, so it sounds like I don't need that resistor at all then? The tractor was already wired for 12 volt when I got it. Or as best I could tell it was. 12 volt battery, alternator, distributor and such anyway. So a 3.0 OM coil and I should be good to go right? Sorry if I keep asking the same stuff you've already told me, I'm just not good with this sort of thing. Thanks again, Brad ------------- Warning! Blind man with a tractor! Head for the hills! |
Posted By: Dave(inMA)
Date Posted: 08 Jan 2017 at 11:41am
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Like Steve said! You don't need the resister. You do need a 12 volt coil with an internal resistance of 2.7-3.3 ohms. Try your local auto parts store and ask them for one. The coil has + and - terminals marked on it. Assuming that your system is negative ground, connect the + coil terminal to the distributor. Wire from the instrument panel connects to the - coil terminal. Dave ------------- WC, CA, D14, WD45 |
Posted By: BradH
Date Posted: 08 Jan 2017 at 12:53pm
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Perfect, that's what I needed to know. I'll call the local parts store tomorrow. There's also some kind of black box mounted to the back of the gas tank support. I asumed this was some kind of regulator , I didn't even know the one in the pictures was there. We wired it into the system, just copying what was already there. Ideas of what it might be? Another of the same thing maybe? Sorry, I didn't get any pictures of that one. Thanks for the help, Brad ------------- Warning! Blind man with a tractor! Head for the hills! |
Posted By: Steve in NJ
Date Posted: 08 Jan 2017 at 1:07pm
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No, that's not correct. The plus (+) goes to the key switch. The minus (-) goes to the Distributor on 12 volt Negative Ground. Neg Grd is to the Distributor points. Then you should be good... Sorry to correct you Dave, hope you didn't hook that up that way on your 45'. If you did, switch it around. (+) to the Distributor would be 12V Pos. Grd. Clear as mud right? Steve@B&B ------------- 39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife |
Posted By: Dakota Dave
Date Posted: 08 Jan 2017 at 2:09pm
| If your switched to 12 volts and running an alternator you can throw the generator regulator away. If your still running a generator swap to an alternator. Alternators will run for decades with no maintance. |
Posted By: BradH
Date Posted: 08 Jan 2017 at 2:29pm
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I'm already running an alternator. So I'll get the 12 volt coil and eliminate those other two parts. Makes my life a lot easier that way. Then I can finally get it starting and running on a regular basis. Then on to the next step. Thanks, Brad ------------- Warning! Blind man with a tractor! Head for the hills! |