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78 Midget ignition electrical kaput

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RickB

RickB

Yoda
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The car died this morning, I was able to push it into a parking space at a gas station. I had a spare electrical side of the ignition switch, so I swapped it in but no joy.

Normally turning the key switches on power to the fuel pump and coil etc. Now it does nothing.
Turning it to start should connect the brown to the white / red stripe wire for starter - but nothing with either switch.
If I use a jumper wire at the back of the switch instead I get starter power.
To get it home I jumpered between my brown at the fuse box to the switched power connectors and then touched brown to white/R to start.
So all that works but not from the switch.

Help me with some steps to diagnose this please, here are the wires at my key switch:

Brown (+12v)
White / red stripe (to starter)
White / green stripe (??)
White (??)
Gray (??)
 
The electrical on the 78......the rotating electic portion, a pigtail about, oh, 8" long with a white plug on the other end to the harness?
You pulled the electrical portion.
Did you try to rotate the electrical portion with a screwdriver to see if that worked?
Could be a failure in the mechanical portion...like the tang broken internally.

Try the screw driver into the electrical end, and see what happens.

Dave
 
Yes, tried that. Nothing. Nada.
 
Couple of things, then.
Are you jumpering at the back of the elctrical portion, or at the unplugged white connector?
The spare electrical....you are certain it is good?

Last, when you checked voltage, and you A) place vehicle in neutral, and B) set the handbrake, do you retain 12V at the electrical portion whan you turn to "start"?

Looking for voltage loss under load.
 
I just took apart one of the switches.
Two ball bearings, two copper contacts and two springs.
The springs are in small holes in the plastic.
One sticks out about 1/8 inch while the opposite spring was pushed down in the hole and not sticking out.
 
I have <span style="font-weight: bold">no </span>reason to think the spare is good.
It was removed from another car and given to me as a possible replacement, I have never seen it work.

I jumpered at the back of the electrical part of the switch with it pulled out of the ignition (key) mechanism. Actually I just touched Brown to White/Red until it started then removed that jumper.

I had already fixed a firm jumper between hot and switched wires at the fuse box so my fuel pump would run.
 
Okay....the contacts sticking in the plastic, usually heat over time melts the plastic a bit and grabs the metal, or kills the spring.
It needs to work smoothly, so it makes good, solid contact.
Can you get enough bits out of both to make one good one?
 
Yeah that's what I was thinking too.
Do you know what the other wires at the back of the switch do?
I don't have a wiring diagram handy.
 
Grn/Wh panel light switch
Red/Wh starter solenoid
Brown-unswitched (or fused) battery from battry post on starter solenoid
Lt Gray - Ignition Power
Dark Gray- Power to fusebox/accessories
Purple- door/ignition buzzer
 
So I got a generic ignition switch from NAPA.
Looks a lot like the switch on the dash of my Sprite.
Installed it in the steering cowl, works great.
Also put in a fuse block that takes the mini fuses.
Then fed it with battery from a relay so that when the key is on that block gets voltage.
Then separated out a bunch of my wires and put proper ends on and plugged it all in.
Now almost all the electrical in my car works.
Still no gauge lights, but that's the only thing that isn't working now.
I'm way happier with the electrical now.

I also swapped in my spare Midget fuse block for the old one and couldn't get voltage to go through it. Went across the street to True Value and bought a .270 rifle bore brush, chucked it up in my drill and went to work on the contacts.
Now it's working great!
 
Here is a picture of my new fuse block.
It is strictly providing switched battery + to things.
The reddish pad under the new fuse block is 1/8" rubber.
The brown side is battery positive that is fused before it feeds this box. The output side feeds things like my electric fan, heater fan, cigar lighter.

The 40amp relay trips when the key is turned on, providing battery + to the new fuse block. Now very little current passes through the ignition switch.
 

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I've got a little wire that's broken and don't know what it is for.
You can barely see it in the picture above - upper left side just below the blue wrapped bundle of wires. It's brown with a purple stripe.
Anyone know?
 
Rick, assuming you are talking about the '78, the brown/purple wire is odd. On the schematic, at one end, it is plugged into a black, ground? wire. (which makes no sense to be) on the other end it seems to end near (but somehow not connected) to the brown wires coming off the starter solenoid.

On the schematic, it shows two brown wires coming from the solenoid. at the first connection (a double) it shows the Brown/Purple coming to an end as a dot beside (but not part of the junction.) At the other end, the black wire goes to the Washer pump.

All of this confuses the heck out of me and makes me wonder whether it is one of the wires that seem to have no purpose at all.

good luck!
 
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