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Ziffdaddy

Ziffdaddy

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Mar 18, 2007
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Location
Altanta, GA
I read through a bunch of threads but I’m not sure what the consensus is, since there seem to be differences. I picked up a gear reduction starter on Amazon and it only has the main battery bolt on and a spade for one more wire. I have these these two wires from my old starter. They both look BW, but that may be age..(mine and the wires). The thin one goes to the coil and I assume the other to ign switch? What do I plug in and where? Does one get left off? Thanks.
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Do they join together since the ign wire gives 12v and the coil wire takes a 12v start up jolt?
 
Your link just goes to Amoron not the specific starter. If the wires have the same codes I think they go to the starter and the ballast resistor on the coil or the coil itself.

Year model market helps get a correct answer sooner
 
Ah, sorry, 76 fj40, US market.
Ha! I didn’t realize it made a link to Amazon..lol. Didn’t mean to do that.
It seems like if the ign switch gives 12v and the coil receives 12 while the key is in start position, they could just join forces? I won’t do that until I hear from you guys about it..
 
Nevermind, I kept searching posts and found one that said discard the coil wire..no need for it now.
Carry on! Sorry for wasting time..
 
Don't discard the smaller BW wire. You may want to wire it to a relay to by-pass the ballast resistor during cranking. That's what the old one did (the relay was part of the starter)

That GR starter will crank your engine faster than the old one. You'll love it. However, without the resistor by-pass feature, your spark will be weaker during cranking, especially when your battery is old and tired.
 
Large BW wire goes to starter, other wire is unused because of the design of GR.

You can do a continuity test of the large Black/White wire to ignition coil and you should have no continuity. Then do a continuity test of the small Black/White wire to the Coil and have continuity.
 
jembourbe said:
Don't discard the smaller BW wire. You may want to wire it to a relay to by-pass the ballast resistor during cranking. That's what the old one did (the relay was part of the starter)

That GR starter will crank your engine faster than the old one. You'll love it. However, without the resistor by-pass feature, your spark will be weaker during cranking, especially when your battery is old and tired.
Click to expand...
Ah, that’s a good idea. Yeah, I wouldn’t eliminate it, but that’s a good use for it if I find the spark is a bit wimpy on crank. Thanks!
 
jembourbe said:
That GR starter will crank your engine faster than the old one. You'll love it. However, without the resistor by-pass feature, your spark will be weaker during cranking, especially when your battery is old and tired.
Click to expand...
How does this work? How do you wire it up? Sounds like it would a difference with cold weather cranking and maybe all around cranking?
 
A little background on ballast resistors and the resistor bypass circuit as it applies to earlier FJ40's -

Earlier ignition systems use a ballast resistor to limit the continuous voltage (running down the road) to the coil + to 7v or so. The purpose of this was to keep from burning points and/or coils, which might happen if 12v or more was applied to coil+ continuously.

Later electronic ignition systems (like used with the oem big cap) don't have that requirement of a ballast resistor as they can handle the full 12v continuously.

Not sure if this applies to your setup, but my 79 had a "cold start" (resistor bypass) circuit that allowed for full battery voltage (12 to 14v) at coil + only while cranking to produce a hot spark, then dropped back to 7v when running.

The "cold start" (resistor bypass) circuit uses the oem starter to create a switched connection from the positive starter cable to the coil +, while cranking only. You might examine your schematic to see how the oem starter is wired internally to accomplish this.
 
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devo said:
How does this work? How do you wire it up? Sounds like it would a difference with cold weather cranking and maybe all around cranking?
Click to expand...
Here you go:

M

Post in thread 'Gear Reduction Starter!'

On older trucks (mine's a '75) the stock wiring harness spits out three wires down near the starter. Two of the wires are Black with White stripe (BW). One of the BW wires is thicker than the other (Big BW). Big BW brings +12v from the key ignition switch, and Small BW takes it from the starter solenoid switch to the (+) coil terminal to by-pass the ballast resistor during cranking. The solenoid switch on the old starter ensured that current was delivered to the (+) coil terminal ONLY when cranking.

The gear reduction starter does not have a terminal for Small BW. It has no...
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So, the GR starter is a beast, but without the small bw wire to send juice to the coil on startup, it takes longer to fire. I guess I’ll put in a relay triggered by the ign wire on the starter to send full 12v on crank?
 
You could do a momentary switch to provide full power to the coil for starting and have the other ign wire to the resistor for running. I think that's what I'll be doing when I put my new coil/resistor in this spring.
 
Ok, to wrap up, I just installed a relay using the small bw as a trigger, as jembourbe suggested. 3D printed a holder for the relay and bolted it to the firewall. Truck starts so quickly it almost seems like it's starting just before I turn the key...LOL. That's in 25F weather! Case closed.. Thanks!
 
Ziffdaddy said:
Ok, to wrap up, I just installed a relay using the small bw as a trigger, as jembourbe suggested. 3D printed a holder for the relay and bolted it to the firewall. Truck starts so quickly it almost seems like it's starting just before I turn the key...LOL. That's in 25F weather! Case closed.. Thanks!
Click to expand...
Glad it worked out for you.

Too bad Woody perma-banned that Mr. Toad fella with the relay idea. I miss him 🤣
 
jembourbe said:
Glad it worked out for you.

Too bad Woody perma-banned that Mr. Toad fella with the relay idea. I miss him 🤣
Click to expand...
Wait, what am I missing? I feel there's a good story here
 
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