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Midget Starter Switch Mystery

GA72TR6

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I've recently restored my '78 Midget's interior and, prior to installing a new wood steering wheel to crown the job, wanted to fix a nagging nasty rigged job on the starter switch. A previous owner installed a generic starter button, I assume because the starter switch went bad years ago. Currently, you turn the key to the on possition and then press the button to start the car (turning the key forward to the crank possition does not turn the motor).

I installed a new started switch, hoping to turn the key forward and hear the sweet sound of an engine crank. But, of course, no such luck. The started button is still connected and it still turns the motor over just as it did before.

I assume the person who did the original rigging bypassed or disconnected something that is opperated by the real idgnitin switch in order to make the starter button work, but I'm not sure where to begin looking. I've been scratching my head and following lines on wiring diagrams, but have not yet ventured under the hood to diagnose the problem. I'm not an electrician, but I have the tools, the diagrams, and the willingness to learn.

Anyone have any ideas about where to begin so I can fire this thing up with the key, install my new wooden steering wheel, and make the car show by mid-May? I appreciate any help!!!
 
Just off the top of my head, I'll bet that the starter button is either inline with the power or ground from the starter switch. Thus, the circuit is interrupted in two places. Connecting the wires on either side of the button should do the job. Check things out with a multimeter first, though!
 
Don't know if this will help, but having just finished re and reing everything in my engine compartment (76 midget) I still remember some of the stuff.

The starter solenoid is activated by the red and white wire from the starter switch/button to an inside contact on the solenoid's side. It is likely that that is the wire which was interrupted by the PO for his button. The red & white wire supplies 12v to the solenoid coil, it DOES NOT ground it.

Good luck
Al /ubbthreads/images/graemlins/canpatriot.GIF
 
Yes, so with the key in the run position, everything is connected as normal, only the line to activate the starter (which is only engaged when the ignition is turned to the start position) is disconnected, and run to the switch instead. You should have either one or two empty terminals on the starter switch (one to 12V, the other to the coil). If this empty connection goes high when you turn to the start position, it's the one you need to connect to the coil side of that starter button.
 
Thanks for the thoughts so far...I'm at least narrowing things down. But, the plot thickens on the starter switch (this is probably no mystery to someone who knows what they're doing!). Anyway, turning the key to the on position before pressing the button turns out to be force of habit -- I tried the button with the key in the off position and the car still cranks.

So, I don't think the add-on starter button is inturrupting the primary starter switch circuit -- it's just connecing power and the starter to fire the car. I assume by connecting the leads currently connected to either side of the secondary starter switch, I'll do nothing but crank the enjine.

So, something is still missing between the primary switch and whatever component it connects to in order to turn over the car when the real starter switch is activated. Is this the red/white wire that should be connected to the solenoid's side? If so, any idea where I should be looking for it to come through the firewall? I hope the PO didn't just rip it out when they did this hack starter button job!

Thanks for everyone's thoughts on this! i can weld, paint, recarpet, and do all mechanical, but I never got the hang of electrons!
 
I was writing this response and got distracted; I wish the people I work with would leave me alone when I’m doing this stuff; anyway I was going to ask the following:
What color wire is going to your starter solenoid?
Can you crank the car over with the push button start if the key is in the off or accessory position?
You answered the second question, which tells me that they just found a hot wire behind the dash to feed the switch. I would expect this since the starter switch has a plug connector. If there is a red/white wire on the solenoid then they probably cut into the harness under the dash and connected the switch leg of the push button start to it, if there is a loose wire (outside a wrapped harness) going to the solenoid then they ran a new wire and the old one is probably still in the engine bay. Pull the real starter switch plug apart, find the red/white wire connection on the harness side of the plug and check for continuity to a red/white wire near the starter solenoid. As I said; it should be in a harness and not a loose wire. I don’t have a ’78 but the earlier harnesses went through the firewall on the passenger side near the fuse box. Let us know what you find and we can go from there.
 
OK...another update. The red/white wire from the actual starter switch is connected at both ends (solinoid and through the harness to the starter switch) as it should be. It's still in the stock loom, so it has not been cut anywhere (most likely).

Also, the hot and ground wires used for the secondary starter switch simply connect the battery terminal of the solinoid to the starter terminal on the solinoid and, when switched on, bypasses the solinoid to send battery directly to the starter. So, the 2ndary starter button is apparently not interfering with the primary starter switch at all.

Any thoughts about where to look next? It is possible that the solinoid is bad...and could cause the stater swich not to connect the battery to the starter terminal inside the solinoid? Is there any way to test it? It's a cheap part, but it will take a few days to get it in while I scratch my head in the mean time.

Thanks again!
 
If you disconnect the red/white wire from the solenoid and jump the positive to where the red/white was connected it should crank, if it doesn't the solenoid is bad, if it does your problem lies elsewhere.
 
I validated that the solenoid was shot -- I put a 12-volt line to the terminal where the red/white wire from the ignition switch connects and nothing happened.

I picked up a new solenoid this afternoon. I removed/replaced each wire and cable one at a time, exactly like the original. Then, with the key in the "off" position, I reconnected the battery. The car cranked. I scratched my head.

I validated the key was in the “off” position. To test, I even disconnected the red/white wire from the switch to the solenoid completely. I reconnected the battery. The car still cranks.

Is it possible that the starter cable (-) and the battery/accessory cables (+) were connected to the wrong terminals on the solenoid all along, reversing the polarity, and engaging the solenoid whenever the battery is connected?

That would make sense to me, but, what is throwing me off is that there is barely enough battery and starter cable to connect this way. It’s also completely opposite of the way it was installed before. Plus, reversing the terminals means you have to also move a metal tang that accessory power plugs into for a (+) charge on the solenoid, and that was installed that way via a nut on the terminal out of the box on the new solenoid.

Any ideas? For reference, the battery, tang, and accessory (+) power connections were on the top terminal and the starter was connected to the bottom on the old solenoid and reconnected in the same way on the new, causing the car to crank whenever the battery was connected.

Help!!!! I’m at my wit’s end on this one.
 
Try to think about electricy as water and wires as pipes. Works easer.
 
Do you have a multitester? Having one will make tracing electric probs much easier.

I would first test to make sure the solenoide you have is good. Sadly, just because it is new, does not mean it is good. Disconnect all the wires except those going to the battery and starter. Does it crank? If yes, most likey the solenoid is locked in the on position. If no, connect to the battery and put the wires back on one at a time until you get crank. When you get crank, you will be able to narrow down the source of the problem to a specific circuit.

I would guess it's either a bad solenoid, a mistake on your connections to the solenoid or a short in your starter switch circuit.
 
I’m doing this from a ’78 California wiring diagram so it may not be correct, but see how close it is. You should have 2 heavy gauge wires (battery positive, and starter), a medium gauge brown wire (alternator) 4 small gauge brown wires, a white / red wire and a white / light green wire. The battery cable, alternator cable, and 4 brown wires should be connected to one of the studs on the solenoid, and the starter cable connected to the other. It shouldn’t matter which one. The white / light green wire should be connected to its own terminal (it may also be connected to the starter cable stud), and the white / red wire to its own. Report what you actually have.
Disconnect all the small gauge wires from the solenoid. Connect the battery, it should not crank. If you jump the terminal from the battery to the terminal that the red / white wire was on it should crank.
If that works, turn on your headlight switch and touch the brown wires that went to the terminal with the battery cable one at a time until the headlights come on, mark this wire with masking tape as headlight feed and set aside. Turn on you hazards and continue touching the other brown wires until they come on leaving them connected long enough for the flasher to operate. Mark this wire hazards and set aside. Have someone hold down your horn push button and continue touching the brown wire (watch your head) until the horn sounds, mark this wire Fuse 1 and set aside. The remaining brown wire should go to your alternator. You can check for continuity at the alternator by disconnecting the wire at the alternator and using an ohm meter, verify and mark alternator. You should now be left with a white / light green wire that goes to your coil as a ballast resistor bypass and the red / white wire that comes from the starter switch.
Pull the #1 fuse and then connect the fuse 1 wire to the stud with the battery cable and connect the red / white wire. Try the switch and see if it cranks. Then with the key in the off position install the #1 fuse. Then start connecting the brown wires and finally the white / light green. Report back with where in that sequence that the car cranks on its own and we’ll go from there.
 
Well, it's not working properly yet, but I believe I have resolution. I followed the process of elimination tests that Morris described, performed multimeter checks on every wire, and validated wires/connections agains ChrisS's description which match exactly what I've got.

Anyway, even when everything but the battery and starter is disconnected, she still cranks.

At the local corner parts store, I took a shot in the dark on another new solenoid. Of course they didn't have it, but the elderly clerk with grease under his nails (the best guy to pose these types of issues to) gave me a simple test -- hook it up so it cranks when it's not supposed to. Then, disconnect the battery. Take a box wrench and whack the soleniod a few times and recoonect. I did, and sure enough, it didn't crank. BUT, as he described, when you turn the switch on, it cranks but keeps cranking when you turn it off. Follow the "whack" process again and it result repeats...continued crank after the initial turn of the ignition switch.

Conclussion....the new solenoid is sticking after it actuates once and the whack releases it. That's obviously not an accpetable way to opperate, but it confirms the bad solenoid.

I've order a new solenoid from the Brit shop and should be in business by Tuesday....in time for the big Brit car event here in Atlanta next w/e.

Thanks to everybody for their help....I now know just about everything there is to know about the starter circuit in my car. Now....on to that coolant system rebuild......

THANKS AGAIN!!!!!
 
Been following this, very intresting. Glad you got it solved.
 
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