Starter ignition circuit thought (1 Viewer)

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There have been some problems with the stock ignition start circuit as cruisers age. Personally, I think some of these problems come from the troubles with the stock solenoid going bad. Starter solenoids usually have two windings (coils) in them. This is to provide the extra power while pulling in the plunger to drive the bendix out to engage the flexplate (flywheel). In a properly operating system the solenoid can see 40-50 amps until the starter starts to spin, then the amps will drop to 10 or so until the motor starts. I think what happens when the solenoids are going bad is people are holding the key on to the start position for extended periods to try to get the motor started. This then allows 40-50 amps to flow through the ignition start switch, neutral safety switch, connectors, etc. for extended periods putting a burden on these parts. In the drawing is a simple solution that can take the burden off the ignition circuit allowing even a defective circuit to flow enough amps to start the cruiser. All it requires is a 50 amp fuse. A 50 amp relay, and a piece of 12 gauge wire. Run a wire from the positive battery post through a fuse to one big lug on the new relay, the other big lug down to the starter solenoid, connecting on where the stock solenoid wire now connects. Then take the stock solenoid wire and run it to one coil post on the new relay, the other coil post going to ground. This way all the ignition circuit has to pass is just a very small amount of amps to pull in the coil of the new relay.
The con with this idea is it adds another component that can fail. If it would fail all that would have to be done is to switch the stock solenoid wire from the relay coil post back to the starter solenoid and the system would be back to stock. An external solenoid can be substituted for the relay I mentioned.
This only has to do with the ignition circuit and not solenoid problems. Also, all this is just my opinion and $.02 worth so take it as such.

Bill
Ignition-bypass-wiring-2.jpg
 
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I like it...
My ignition switch is not as it used to be.
I have a 12g jumper wire, in the door just in case need it to start the cruiser.
 
bill, is this what was discussed lightly in roncruiser's thread when a bloke from Aussyland commented that a lot of aussies use a bypass wire for the ignition?
 
bill, is this what was discussed lightly in roncruiser's thread when a bloke from Aussyland commented that a lot of aussies use a bypass wire for the ignition?

You sir are correct. I now found the old thread and it looks like I've reinvented the wheel. :doh:
I'll delete this thread.

Edit - I've lost the power! I can't find how to delete my own thread. Oh wait, maybe I never had the power.


Bill
 
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Medtro asked me the gauge of the small wire that runs to the stock solenoid. My brain is on vacation so I forgot I even posted this thread. :doh: Anyway, Medtro your inbox is full so I will post the wire sizes here. I only measured the outside wire dimensions so take it for what it is worth. 14 gauge NAPA Belkin wire is .119"; 12 gauge is .143 inch. The Toyota black with red stripe solenoid wire is .137 inches so at least on the outside is in the 12 gauge ballpark.

Bill
 
Medtro asked me the gauge of the small wire that runs to the stock solenoid. My brain is on vacation so I forgot I even posted this thread. :doh: Anyway, Medtro your inbox is full so I will post the wire sizes here. I only measured the outside wire dimensions so take it for what it is worth. 14 gauge NAPA Belkin wire is .119"; 12 gauge is .143 inch. The Toyota black with red stripe solenoid wire is .137 inches so at least on the outside is in the 12 gauge ballpark.

Bill

I'm getting ready to replace that wire from NSS to starter solenoid, I'll let you know what gauge it is when I get it out.
 
Hey PHOTOMAN, which solenoid did you use? Went to Pep Boys and they have tons of them. I mean its just a standard Ford starter solenoid and I found several that are 2 wire, some 1 wire. But their stupid listings don't rate amperage and I have no clue what could possibly be the difference between them. Is there a part number/manufacturer that you rocked?
 
Personally I prefer the 4 terminal with one of the small terminals that go to ground. This wire can be run to the battery negative or a body or engine ground which I feel is more dependable than having to use the body of the solenoid to make contact for ground.
In NAPA the one I will go with and like is the ST 80. It has silver contacts and is rated continuous duty. If you want copper contacts the number is ST 85. Some other numbers are ST 71, and ST 67 for the old Dodge solenoids.
The Ford solenoids can be used like the popular ST 81. It is a 4 terminal but with a grounded base iirc. I think one of the small terminals becomes energized when the key would be turned to start so would not be used. If you use this one meter it out first as I can’t remember exactly. HTH

Bill
 
ST80 it is! Thanx Bill.

BTW, I loved your coolant level alarm mod I went overboard and added one to the windshield washer fluid :beer:

Now you need to make a reliable engine oil and PS fluid level monitor :grinpimp:
 
Thanks NLXTACY.

You know it has further occurred to me that this new circuit would be a good spot to install a starter disabling switch or some such for security. An ST 80 solenoid only draws a small amount of ohms to operate (16-21). Since the stock starter circuit now only has to pass roughly ½ amp to start the cruiser, adding a hidden switch in the circuit with additional wiring would not be that much of a burden. Just a thought.

Bill
 
Bill, do up a schematic and I will try it out. I've been talking to the 12 volt guy about his kill switch: 12VoltGuy.com: Theft Switch

I was just going to wire this in between one of the lugs on the solenoid for your set up. But if this thing can kill two birds or if there is a way to combine them that would be most excellent:grinpimp:
 
I would put it on the coil side of the relay. With this new circuit this part should only see very low amps. The big wire side could still see 40-50 amps so I would not run that side through a switch. By the way, I would use a good quality switch; otherwise after a while with a cheapo, the cruiser may not want to start. One switch I had considered when doing these types of things was a simple key switch. That way even if it is found it is a little harder to defeat it as long as the switch is installed through something so the wires are protected. The old Ford 9N and 8N tractors have simple two wire ignition switches iirc so one like that would work.

Bill
Ignition-bypass-wiring-3.jpg
 
Hey Bill, still haven't had a chance to do this this BUT while I was searching for a aux. fuse panel I ran across this little gem:
Painless 30201 - Painless Hot Shot Relay - JEGS

Looks like it will not only do exactly what you are recommending but it ALSO does the cool engine bumping that is sometimes helpful when doing stuff like valve adjustment or anything else where you need the engine to just turn over without having someone else around.
 
Looks good. If you prefer using a larger relay or solenoid here is another way to do the original idea and it will allow bumping the engine. It would just take a small automotive relay and a momentary push button switch. Many ways to do things.

Bill
Ignition-bypass-wiring-with-push-button-relay.jpg
Relay-push-button-wiring.jpg
 
Im trying to do this mod but im trying to figure out how to wire from st80 solenoid to stock solenoid. Specifically which terminal? Im assuming the power terminal. But how do you trigger the starter itself? Did u guys use jumpers to connect the power and ignition posts?
 
The stock starter/solenoid has two wires going to it. A large wire from battery positive and a small wire from the ignition switch. The small wire is the one you are interested in. This wire gets cut and extended. The one end that goes to the stock solenoid goes to a large terminal on the new solenoid. A new wire is connected from the other large terminal, through a fuse to battery positive. The other end of the cut wire; the one from the ignition switch, goes to one of the small terminals on the new solenoid. The other small terminal on the new solenoid goes to ground through a new wire that is added.
In action, when the key is turned to start whatever power is available that comes through the neutral safety switch and ignition switch now goes to one small terminal on the new solenoid. This activates the coil in the new solenoid causing the contacts to close. This allows full power from the battery to flow to the stock solenoid through the large terminals on the new solenoid.
 

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