engine will not shut off

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BERHAN
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Posts: 44
Joined: Thu May 28, 2009 8:20 pm
Location: Glendale,Az

engine will not shut off

Post by BERHAN »

here's one for you all, my 1966 beetle sedan has been converted to 12 volts over 20 years ago, lately, couple of days now, when I turn the key off, the alternator charge light comes on but the motor still runs....until I step on the brakes, then it turns off no problem. Nothing new has been added or wired in. I think my ignition switch is giving up the ghost, any ideas of what may going on?
darzoom
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Joined: Mon Jun 13, 2011 10:32 am
Location: Atlanta

Post by darzoom »

Consulting the wiring diagram on this site, I think you are right on. The hotwire from the switch (post 15/54) goes to the fuse block and jumpers to the coil. That is if your wiring has not been buggered with. The switch (post 15/54) seems to be not working correctly.

The brake light circuit, horn and wiper hot feeds are on the other side of the same connection on the fuse block as the coil hotwire jumper. That might explain might explain why hitting the brake causes it to shut off as it may cause extra amperage draw back to the switch and cause the contact to release.

You may be able to bend the dimpled metal back and open the backside if the switch to inspect and clean. If this is a daily driver, you might want to have a back up switch ready.

You could always add a battery cut off switch which would also be a theft deterrent. I used to put them on sand rails.
BERHAN
Member
Posts: 44
Joined: Thu May 28, 2009 8:20 pm
Location: Glendale,Az

Post by BERHAN »

I already ordered a replacement switch, thanks for double checking my diagnostics, was ready to pull my hair out
darzoom
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Posts: 468
Joined: Mon Jun 13, 2011 10:32 am
Location: Atlanta

Post by darzoom »

Keep your hair. You will need it for the next chapter of owning a 50+ year old car.
BERHAN
Member
Posts: 44
Joined: Thu May 28, 2009 8:20 pm
Location: Glendale,Az

Post by BERHAN »

For sure
BERHAN
Member
Posts: 44
Joined: Thu May 28, 2009 8:20 pm
Location: Glendale,Az

Post by BERHAN »

I found a fix for my problem. My car has and MSD ignition system, apparently, the ignition system will run, on very, very low current. The MSD ignition system comes with a diode, which can be used for run on conditions, it appears that the smallest amount of current from the alternator charge light can cause the MSD ignition not to turn off, this is where the diode is installed. it is installed in-line between the charge light bulb and charge supply wire. I installed the diode and all is perfect now, thanks to everyone for feedback and troubleshooting tips,
KKV270
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Joined: Wed Jan 16, 2013 1:11 pm
Location: Nairobi- Kenya

Post by KKV270 »

What are the odds- I experienced the very same problem today on a long safari. After hours of driving, pulling-over just to refresh and the bus wouldn't go off despite turning the ignition key off....

It only happened once though. All other attempts worked normal.
Cheers
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