Jumpimg the resistor at start-up

[rockfla]

I have a 39 Merc and remember the chatter about jumping the resistor at start up. Tired of using a penny, can anyone give me the parts needed and the wiring set up for getting the full 6V at the points for starting??

[Don]

Pretty simple,just run a wire From full 6 volts thru a momentary switch ( push button ) to the wire on dist,this will bypass the resistor when you push button putting full 6 volts to dist to improve spark.

[42merc]

As a youngster driving worn out flatheads, using a fifty cent piece (half dollar) would jump out the resistor to get it started.

[Old Henry]

Here are the instructions and diagram: http://www.earlyfordv8.org/forum/fil...k%20Start1.jpg

And a recent thread all about it here: https://www.fordbarn.com/forum/showthread.php?t=135874

[BUBBAS IGNITION]

Just a note here as the voltage wont be exact six volts as the starter will eat up some volts as well as the cables etc...4.5 volts while cranking is pretty typical...

[donQ]

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I believe you can use a horn relay connected to your starter solenoid. When you hit the start button, the horn relay points will close. A wire from the battery to the relay and then to the coil will bypass the resistor only when the engine is cranking.
donQ

[Graeme / New Zealand]

I've just done the bypass with the diode thing and am amazed at the better starting.

GB

[mhsprecher]

I just read this and the thread that Old Henry put in his response. The one to the V8 Forum does not work, so if someone has a better or another link, I would love to see it.


My 45 truck had some problems starting, which were rectified when I cleaned the connections to the resistor. My 39, however, did not respond to cleaning. I jumped the resistor on both sides of it with a wire with alligator clips and it started. When I removed the wire and tried to start it again, no dice. I ran out of time this evening to try and jump it again.


I recently added a ground strap from the starter to the frame, which seemed to help it crank better. I still needed to jump the resistor. I have a replacement resistor, but wonder why we need to jump it? Is there a weakness or drop in voltage that requires that we jump the resistor in some way? It seems to me that if everything is working properly, it should start without putting in a diode or jump switch of some sort. It also seems odd that I have had the same problem with both of my V8s at once. I have a lot to learn about automotive electrics and V8s, so I can't really figure it out.


I am hoping that someone can explain why this is happening?


Thanks,

[Tinker]

Super old post... but.............



If you don't mind the look. On 6 volt you can use a ford tractor 4 post starter solenoid. Has full "6" volts to the coil (run a wire, bypasses resistor). Then when not cranking it goes through the resistor, like later ford solenoids.



Cheap too.
https://www.yesterdaystractors.com/3...BoCy5gQAvD_BwE

[Tinker]

Could be a bad resistor precher.

[mhsprecher]

I have a replacement resistor. I will try that, too. BTW, I replaced the condenser during this process and the coil is a Skip Haney coil.



Reading other threads, it would seem that not enough current is getting through the resistor to the coil. It could be the resistor or somewhere before the resistor. Adding the ground from the starter to the frame helped with cranking speed, but not as good as my truck, for whatever reason. I will replace the resistor tomorrow, but it would seem to me that the resistor either works or it doesn't and the reason it wouldn't would be because the wire in the resistor had broken?

[Tinker]

Put a volt meter at you coil lead and ground the other meter lead. Should be around 3-4volts with the ignition switch on. Don't need to start the engine. But don't leave the switch on either for long as it will smoke the coil.

Meter at the coil lead will be easier then trying to do it under the dash.


Maybe a bad part and is not wound right. Lots of variables.


I run it like factory, 3-4volts works for me no need for a jumper.


"I replaced the condenser during"... might put the old condenser on first as it's easier to change. But you can rule that out if you get a good reading of the resistor.



.

[fordwife]

I've always wondered, why didn't the ford engineers think of this in the 6 volt days? they waited until they went to 12volts when they added another terminal to the starter solenoid for this purpose.

[Tinker]

Cost to redesign most likely. At the time fords were affordable. No gizmos to hike costs. But it could be that none thought of it before. Things we think are a no brainier were very inventive in the day. Before the self righting steering wheel you had to turn the steering wheel back to center with the same force. Now it's inconceivable.


Early yblocks used a 6volt coil also. Used a ceramic resistor. That resistor is a great resistor to drop 12 to 6. 4 post on 12v gave a quick jolt to the system.


Tractors stayed 6v for far longer.



.

[Tinker]

.... double post
.

[Ken/Alabama]

I would find the problem as opposed to running jumper wires and adding relays. But that’s just me.

[JSeery]

A lot (maybe all) of the current original style ignition resistors are of very low quality.
The voltage check at the coil only works when the points ate closed.

[big job]

I think due to brain memory I wrote this before. I have been slowly going into this
even to have to use a jump pack. I first blame a 7mo old commercial Napa 6vt battery.
Napa gave me a new one same deal. Aside from all the ground postings here and
my grounds are good and I have a genuine 'new' starter my father bought from the
Ford dealer still in the box back in the day. Volt meter read around 4 volts when pressing
the button. Sure enough in fathers wall mounted Standard cabinet a new solenoid, nothing in this cabinet is newer than mid 50's so it ain't made in China. Now it starts
as fast as you hit the button. So don't overlook the solenoid and this must have a
good ground . Some of my age buddies said what? you went to 12vts - Nope ! So
I say to take any solenoid apart and most if not all have two contacts one batt. and the
other starter with a round copper disk actuated by a coil. By all these years the disk and
the contacts are black and corroded and thats a big current drop (a leak) like flashlight
battery's.