55 F100 start button
 

Should I have a start button on my 55 F100? There is a hole on the left side of the dash that has a metal plug in it. The current ignition switch has the start position on it. The manual does mention the start button, but then it also mentions 12 Volt. Any help? Thanks...

Re: 55 F100 start button
 

If it works now, why change it? It can be any way you want it to be.

Re: 55 F100 start button
 

I googled for pictures and it appears that there is a starter button on the extreme left.

Re: 55 F100 start button
 

Good Job, I could never find one with that corner of the dash..

I agree. I have to run some new wires, and I always liked that start button. It is a tight area to get into though.

Thanks for inputs. I am still trying to figure out if I am man enough to connect the battery with positive ground!

Re: 55 F100 start button
 

It's the original 6 volt positive ground?
Not a big deal... The only parts of the truck that care if it's positive or negative ground are the generator and ignition coil. (and maybe a factory radio if it has one that still works)

If the two small Ignition Coil terminals are labeled "+" and "-" the Plus terminal connects to the wire leading to the points.

With everything connected and before you try starting the truck, the generator needs to be polarized by removing the Field wire from the voltage regulator and quickly touching it to the Battery terminal of the voltage regulator, then reattaching the Field wire to its terminal.

I don't believe trucks had an optional clock, so you won't have to check the polarity of it.

Re: 55 F100 start button
 

Yes, still 6 volt. My next step is to connect the cables. Thanks

Re: 55 F100 start button
 

I added a wiring diagram to my previous reply.

Both battery cables & the Solenoid to Starter power cable need to be quite large, #1 or 'zero' gauge is appropriate. About the size of your thumb, not the smaller generic 4 or 6 ga ones sold for 12v cars at the corner parts store.

The Ground end of the Plus battery cable should connect to a convenient bolt on the block or head. Also a large Ground connection from the block to the body of the truck. (photo #1) There are a couple bolts/bolt holes at the left rear of the engine that can usually be used.
Caution: the one closest to the Temp sender (photo #2) goes into a pushrod passage in the head, if the bolt is too long it will hit the pushrod.

If the truck has an Amp meter in the dash I'll assume it's still hooked up correctly.

These example photos are from a Tbird but the wiring function you'll need is the same.

Re: 55 F100 start button
 

What manual is it that mentions positive ground and 12 Volts.

Re: 55 F100 start button
 

It is the 54/55 shop manual. I am not saying they are mentioned together, but just statements in the manual.

Re: 55 F100 start button
 

Ok was curious, thought Ford didn't change to 12 volts in 56 along with neg ground.

Re: 55 F100 start button
 

Up to 1955 all were 6vt pos ground. And yes all up to 1955 has a start button. This
button works on ground (one wire going to the solenoid) so this solenoid is different than
most, being the small start terminal that needs ground to work . So the button housing
is grounded to the dash and when pushed it shoots ground to the solenoid. OK you start
engine with the ignition switch, right there tells me you need the original type solenoid
that works by ground that uses the start button all venders carry those even Napa I just
bought this 6vt solonoid from Napa last week. Thinking someone put a universal or a
1956 ignition switch in there that shoots power to the solonoid not ground. I think the
reason is back then you push start left hand and right hand for the choke: Makes sense
to me. sam

Re: 55 F100 start button
 

then google cars and trucks late 30's up to 1956 when all makers went 12vts
neg ground. Not to mention the heavy trucks and buses were 12volt pos ground maybe since 1941 or so.

Re: 55 F100 start button
 

That is what is confusing me also. But maybe the big trucks are included as bigjob mentioned, they were 12 volts.