My Car Won't Turn Off

[kjo]

I have a 1975 280Z.

I just replaced the starter and the regulator and it started up just fine. I went to turn it off and it kept running! I played with the key and it turned off. Could it be just coinsidence and maybe my ignition is wearing or my key is too worn...

but the weird thing was when I took off the regulator it wasn't even plugged in....

the plug from the reg was taped next to the female plug. there were some wires taped into the female end but they did not connect to the male end at all.....

can you help??

I am a beginner z person and am still learing

thanks for your help....

[EScanlon]

I would check the switch behind the ignition key lock first. Sounds as though it might be failing or it has come loose from the back of the lock.

The other items you mention also need to be addressed, but I'm not sure if they would bypass the ignition key circuitry.

2¢

[Bambikiller240]

My experience is solely with 240Z's but it sounds like the car originally came with the 240Z type of Alternator with an external voltage regulator, and that someone replace the Alt. with an internally regulated one. IF this was done they would have left the old regulator un-connected and made a jumper wire or two at the wiring harness. In some cases people have had to add a diode to the circuit to keep current from flowing "backwards" and preventing the vehicle from responding to the ignition switch being turned off.

I'm sure others with more specific information will chime in here, but I don't believe this problem will be difficult or expensive to resolve.

OK, Z Electrics Upgraders, this is your que to leap in and help kjo!

[Zedrally]

Yep, same problem occured when I changed over to IR,

Just to make sure, pull the reg plug and see what happens!

[kjo]

ok I pulled the plug on the new regulator and the car wouldn't turn over...

could it be something with my ignition instead of the reg??

thanks

[Bambikiller240]

kjo originally posted:

but the weird thing was when I took off the regulator it wasn't even plugged in....

the plug from the reg was taped next to the female plug. there were some wires taped into the female end but they did not connect to the male end at all.....

Just curious, if the Voltage Reg. was not even plugged in, WHY would you replace it? Was the car working normally before you put the new one in and plugged it back into the electrical system?

When you plugged in the new Volt Reg, I assume you had to remove the "wires taped into the female end".

If the car was working normally WITHOUT the Reg and WITH those "taped in" wires, when you now remove the connection to the Reg, you'll have to re-intall those wires in the female connector to get things back to normal. Just be sure that you get them back EXACTLY where they were originally, or you'll FRY something, if not EVERYTHING!!!!!

[kjo]

I didn't even look at the reg before ordering a new one...I just knew it hadn't been replaced and I was ordering stuff to dress up the engine compartment.....yeah I know measure twice cut once and I didn't do it......

[Zedrally]

kjo originally posted:

but the weird thing was when I took off the regulator it wasn't even plugged in....

the plug from the reg was taped next to the female plug. there were some wires taped into the female end but they did not connect to the male end at all.....

There has to be a diode somewhere in this circuit and I wouldn't mind betting that it's somewhere in the taped wires.

What I should have advised was, to put the setup back as it was. Have a look around for the location of the diode, it's very important as it stops the battery from discharging after the engine is turned off. Good luck and let us know where you found the diiode.

[sudhirjin]

I changed the regulator on my 240z, 1971. now suddenly it wont stop even after the key is turned off and removed. mechanic said its problem with the lock, but now reading this i can understand that its not. because even my regulator was changed.

[FastWoman]

Well, do you know whether you have the internally regulated 60A alternator on your car? (I don't know the identirying features.) Dave ("ZsOndabrain") knows a lot about these conversions, so he's probably the one to help you. I've never done an alternator retrofit. However, I suspect the power is backfeeding from your alternator, through the voltage regulator, to the ignition circuit, thereby keeping your car running. This is often solved with a diode, but I would think it could also be eliminated by removing the (pointless) voltage regulator. Right? (Dave???)

[Zed Head]

I don't think that your problem is related to the original 2002 post, unless you also removed some jumper wires so that you could plug the old regulator back in. Was the old regulator plugged in before you replaced it? If it was, then your mechanic might be right. The key can be removed from the ignition on these old cars, in any position. Why did you feel the need to replace the regulator?

All of the ZX alternator upgrade write-ups described leaving the old regulator unplugged, most suggest removing it. You can't follow the instructions AND end up with the old regulator plugged in to the harness.

It would be odd if the car would run with an internally regulated alternator running through an external regulator. I can't say it's not possible though.