Push-Button Starter Questions

U

ungoliant

New member
Okay so I recently bought a '75 Scout II xlc, it's had a push button start rigged up on it. It's the 345 v8 with 3 speed automatic, 4x4, and carbureted it was running yesterday (when I got it), but now here's what happens:

put in the key, turn the key, hold the start button till it fires up. Fires up, I let go of the button, engine shuts off.

I can sit there and hold the start button and it will run as long as I hold the button, but the second I let off it, the engine cuts out.

What might be the issue? Wiring? Ignition switch? I'm kinda lost. It run and drives fine otherwise.
 
Sounds like some classic po wiring "upgrades". Pretty common stuff. In order for the engine to keep running after initial combustion, the + terminal of the coil must be fed a continuous supply of current which is normally accomplished with the key in the on position. When everything is right, turning off the key cuts the voltage supply to the coil which kills the engine. So you need to figure out why voltage is not being fed to the coil with the key on. There could be a variety of possible causes, some of which you've already listed. Hope you've got a 12v test light.
 
Atleast my po shitbox wiring wired a toggle switch in line for master power instead of trying to use the key.

It was still jacked up like this though.

If you have the $$ I would suggest just getting a 14 circuit kwikwire from Jeff and redoing it right.

As I found with my po wiring upgrades, he insulated the twisted wires with some high quality blue painters tape. It is no wonder my Scout didnt catch fire and burn down.

The 14 circuit kwikwire harness is super easy to install, even if you have no idea what you are doing when it comes to wiring. I was able to get about 90% of the wiring done in a weekend, and the first time I keyed the ignition it fired up.

A full rewire will also teach you about how the different components are connected and how each circuit works with each other.
 
Well I took a stab and replaced the ignition coil before I got too hard in depth with testing a bunch of stuff, and that fixed it.

Still got the test light, but I'm glad it was a good guess.
 
Since you say your coil went bad I am thinking part of your po wiring mismash has eliminated the run side of the starting circuit.

Running 12-volts all the time through a standard coil can burn them up over time.

I think korllach's idea of rewiring everything would be a smart use of your time and $$$.

Good luck.

Mark o.
Winlock, wa
 
The coil itself should not have caused your issue. What I suspect is that in the process of replacing the coil you "fixed" or "wiggled" a poor or bad or missing connection from the key "on" to the points.

It was running when the starter was cranking because there is a "bypass" wire that leads from the starter to the coil/points to supply a full 12v when cranking. When you stop 'cranking', power to keep the truck running is supplied by the "key on" position providing a reduced voltage (to save the points from excess wear) through a resistor wire or resistor block.

Sounds to me that that is where your problem was, and it got "fixed" when you changed the coil.
 
marko said:
since you say your coil went bad I am thinking part of your po wiring mismash has eliminated the run side of the starting circuit.

Running 12-volts all the time through a standard coil can burn them up over time.

I think korllach's idea of rewiring everything would be a smart use of your time and $$$.

Good luck.

Mark o.
Winlock, wa
Click to expand...

Not a factual statement regarding the operating voltage of the ignition coil.

The nominal 12vdc inductive-type ignition coil can actually run on an input of upwards of 18vdc with no ill effect. The actual operating voltage of the entire electrical system when the engine is running and the alternator is producing is actually a nominal 13.8>14.2vdc, it is not "12 volts"!

We've discussed this "coil" primary voltage and "primary resistance" deal over and over in many threads in the ignition tech sub-forum.

Inna "conventional" battery-powered, inductive ignition system using breaker points for the switch, we feed a "bypassed" b+ to the coil positive terminal during cranking. Once the engine fires and is running, we feed a "reduced" voltage to the coil positive terminal in order to control primary current (measured in amperes) across the breaker points to ground.

That current (load) is controlled to a nominal 2.5>3.5 amps continuous duty cycle by the dwell specification of the breaker point system/cam and the primary resistance specification of the ignition coil once it's at operating temperature. And distributor rpm also enters into the equation.

If the primary current/dwell is too "low", then we have random misfire under load, scatter firing, and ignition system shutdown at elevated rpm. If the primary current /dwell is too "high", then the breaker point life is drastically shortened (say...30 minutes of operation??), the points can actually weld themselves together if the insulated arm does not burn through first.

Not every breaker point/inductive ignition system uses a "ballasted " operating scenario, other manufacturers use ignition coils with other primary resistance values, and distributors with alternative dwell factors. This is why the ignition coil on any inductive system must "match" the system, this is not a "they are all the same" scenario, there are thousands of canister-type ignition coils that look similar but are not identical specification electrically-speaking.

Why re-wire the entire vehicle if only the ignition system needs attention???
 
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I only suggested it because of the past 2 scouts I have owned the wiring was all jacked up. From the sounds of the ignition wiring. Had flashbacks of mine.

If the rest of the wiring seems safe ( not insulated with painters tape) and you are fine with the push button alternative. Then run with it. I havnt been happier after rewiring my rig. I know that everything is safe and works and I don't have to keep 3 fire extinguishers in my front seat!
 
So, with the aquisition of henry (what the wife calls the pickup that she has now stolen from me) I find myself with a toggle on off switch, a points / coil dizzy, a push button starter, and some stuff wired up with speaker wire (atleast they used electrical tape this time).

My question is based on the pics under the hood how should this wiring scheme look in order to get this guy going.

I am from eastern oregon so I respond well to things like gitcher self a waaar from this dohickey to that one!:cornut:

img_0271.jpg


img_0272.jpg


So it looks like there is a blue wire going from the + terminal to a resistor on the fender. But nothing connecting it to the dizzy or coil.

The red wire looks like it goes back up under the dash and is wired to the toggle switch for power to turn on the electric fuel pump. The black wire coming out of it, is taped to some speaker wire and I can only assume it goes into the half ass crimped wire that was connected to the ground terminal.

From the coil to the dizzy there is some interesting looking wiring, however I have no idea if it should be there or not.

img_0273.jpg


img_0274.jpg


There are also these guys on the passenger fender not sure what they are.

img_0275.jpg
 
The one is a windshield washer pump and the other is your voltage regulator. There is supposed to be a bottle in the bracket on the fire wall for the washer reservoir.
 
Ignition system primary wiring is exactly the same wire runs as what you did when installing the new system in your sii.

However, that six banger will use that ballast resistor already mounted on the coil instead of an oem-type "resistor wire to feed the coil positive terminal off the "run" side of the ignition switch. That ballast resistor is hopefully "good", so test with an ohmmeter before cleaning up all that mess. The correct value for a ballast for a six cylinder distributor system should be between 2.0 and 3.0 ohms nominal for correct current draw and coil saturation for that system. Coil primary resistance can be the same as for a v8...though a coil with a primary resistance of 2.0>2.5 ohms is best, that is not a dealbreaker though.the ballast has no polarity, doesn't matter which way current flows through it.

Even if the system has been botched to separate the two functions of the ignition switch as described, the ballast must be used with the breaker points and a coil of the correct primary resistance, otherwise the engine will run poorly or the breaker points will burn up in short order.

That single pole starter relay has been added most likely as a workaround for another issue, I'd shitcan everything you see there in the way of po wiring and start from scratch wiring it right. That relay is now deadheaded as shown in the pic even when a battery is installed, toss it out it has no use.

The stickee in the electrical sub-forum describes the "remote starter relay" deal, the wiring is no different on that c truck than on any other breaker point/alternator system.

Down the line, ya May wanna stick a pertronix in the distributor (which is a delco unit).
 
I was just talkin with my boss about the petronix unit. Will the one advertsed on the ihon online store work or will it need to be a call Jeff and ask for the right part kinda thing?
 
korllach said:
I was just talkin with my boss about the petronix unit. Will the one advertsed on the ihon online store work or will it need to be a call Jeff and ask for the right part kinda thing?
Click to expand...

No, the pertronix units we stock for the four cylinder Holley and the v8 Holley distributors won't work. The actual pertronix for your six cylinder delco application is totally different.

I'm looking in a pertronix master catalog right now, it's possible you have one of two different distributors, each use their own dedicated unit. Can you post me the model and part number information of the distributor and I'll give you the correct part number to use? Pics of the distributor with the cap removed will be of great help also.
 
Roger that, it will be Monday before I can get that.



To be clear:

gut the 3 post module on the fender with the blue wire coming out of it.

Ensure the connections to the power are all good, and the connections to the coil and dizzy are good.

Ensure the connections for the electric fuel pump are in order.

I need to grab my wiring manual for that kwikwire harness that I got. The great thing and the terrible thign about the kwikwire product is it is so user friendly you dont retain a lot of the knowledge ;)
 
You got it!

I'll post ya a wiring diagram for the engine bay in your reader's rides thread once I locate one in my collection.

The oem wiring on these roundbody rigs I feel is somewhat superior to the later stuff done on the squarebody and the Scout II platforms. I bet you will find that one really not all po-scruud as is typical and it's much better to simply repair the oem stuff as needed to maintain functionality.

Anything that is rat-chewed and pissed can be handled onna wire-by-wire basis.
 
Thats just it, the oem wiring looks fantastic and simple and well thought out. The only thing that is hacked up is where the po has tried to bypass the oe wiring, or replacing the mechanical fuel pump with the electric one.


I found the kids drivers license in the glove box who owned this before me. I bought it through a guy who was trying flip the rig and make some dough, but because he had no idea what he had, he wanted out of it because he couldnt get it to run.

Kid is 19, probably inheirited the pickup from gramps, lost the key or such so bypassed the ignition. Then drove it till the clutch went out and parked it.

The truck really is just clean and straight. It blows my mind.

I chalk it up to good fortune at the expense of 2 kids who had no idea what they were dealing with.

The more I think about it, I think we will keep it, get it looking good and just have a cruising pickup.
 
korllach said:
thats just it, the oem wiring looks fantastic and simple and well thought out. The only thing that is hacked up is where the po has tried to bypass the oe wiring, or replacing the mechanical fuel pump with the electric one.


I found the kids drivers license in the glove box who owned this before me. I bought it through a guy who was trying flip the rig and make some dough, but because he had no idea what he had, he wanted out of it because he couldnt get it to run.

Kid is 19, probably inheirited the pickup from gramps, lost the key or such so bypassed the ignition. Then drove it till the clutch went out and parked it.

The truck really is just clean and straight. It blows my mind.

I chalk it up to good fortune at the expense of 2 kids who had no idea what they were dealing with.

The more I think about it, I think we will keep it, get it looking good and just have a cruising pickup.
Click to expand...

I agree with your assessment from what I can see in the pics! That one is exceptional and the six banger makes it really special in my book! Excellent fixerupper!
 
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Quick question on that coil:

can I get rid of that beige looking thing that has that shiny screw in it and just run a wire from the post on the coil to the distributor? That thing looks like some knuckle head rural telecom guy was drinkin 1 too many keystones while adding some "custom" touches.

From the wiring diagram it looks like I can just run a single wire to it.
 
korllach said:
quick question on that coil:

can I get rid of that beige looking thing that has that shiny screw in it and just run a wire from the post on the coil to the distributor? That thing looks like some knuckle head rural telecom guy was drinkin 1 too many keystones while adding some "custom" touches.

From the wiring diagram it looks like I can just run a single wire to it.
Click to expand...

That keystone thing is the aftermarket ballast resistor that some dufus added in place of the original resistor wire called out as "circuit #12" in note 1. These vehicles did not use a "bypass" to feed b+ to the coil with the ignition switch in the "start" position like the Scout II and the "d" model rigs did. So that ignition switch is "jumped" internally to provide current to both the s and the I terminals when the switch is in "start" and in "run" position.

The ballast resistor was added to replace the burned out oem resistor wire which as stated, measured out at a nominal 1.8ohms. If you eliminate it, the coil will see b+ (charging voltage) continuously which will increase current through the breaker points which greatly shortens their service life up to the point where they are fried or weld the contacts together.

To "hot wire" (no key switch required) any battery-powered, breaker point system, all ya need is a light gauge jumper wire from the battery positive terminal to the coil positive terminal. The coil and points will immediately begin to "heat" unless the engine is cranking over. Then use a screwdriver to short the starter s terminal to the battery stud on the solenoid and the starter will spin and engine will fire and run. But within 10 minutes or so, the points will likely fail. This can be done safely as a "test" however, just don't try and run it that way very long. To kill the motor, just pull the jumper off!

That single pole relay with the blue wire and the leftover remains of a circuit breaker above it tell me someone rigged that to charge a second battery probably on a trailer. That is an oldskool method for "isolating" the secondary battery from the vehicle battery...it can charge both batteries, but the trailer cannot discharge the truck battery. Nowadays we use an electronic isolator (diode block) to accomplish that function. That add-on was not part of the ignition system other than being "switched" on and off by the ignition switch depending upon how dufus wired it!
 
I read that in note 1 and was confirming if it were true. It looks like the wire for circuit 12 is still there and is in bad shape see about replacing it. If I read the schematic right it is an 18 ga wire running 72" to achieve the required 1.8 ohms resistance.

Thanks again for your help mr. Mayben. I will have progress reports tomorrow or Monday. Currently in walla walla grabbing some reloading gear. Dillon multistage press with dies brass powder and bullets for .45 acp, .223, .30-06 ( gotta keep the m1 garande fed;p )
 
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