72 240z shut off on me while driving

[blue72]

Here's a picture of my '72's engine bay with an arrow to the fuel filter. It is held in the engine bay with a bracket.

 

 

I had the fun experience of changing starters and not marking the wires. I wound up putting two of them on backwards, and fried the ammeter in the dash. I would go through and make sure all of your connections are good. As extra protection you might go to autozone.com, or google '72 240Z wiring harness. I have a few saved on my hard drive that show exactly which wires go to where, and you can determine which fuse controls what pretty well.

[vqpwrd240]

Thanks. Got the fuel filter all taken care of. The alternator hook up is correct.

 

I decided to unplug the voltage regulator to see if the voltage would still increase and over charge the battery. The voltage stayed at 12.4 or so. I let the car running for a while and it did not decrease or increase at all. I drove it around the block and checked again. Still the same. I checked the wires and they were not hot and the one off the started was not smoking. Not really sure what is going on here.

 

Ferhan

[Soundmasterg]

Does your car have the stock alternator, or did someone replace it with a later one? The original ones on the early Z's used the external voltage regulator, but many aftermarket replacements were internally regulated. Perhaps this could be the case with yours and it doesn't need the external one?

 

Greg

[Zdigg]

I had that happen when I first bought my z and was driving it home... pretty funny on the side of the road with expired tags and a non-op title... ended up being a bad wiring job on the battery, the negative wire vibrated off its grounding.

[vqpwrd240]

The alternator looks like it is the stock or original one to me. Here is a picture of it.

 

 

Ferhan

[vqpwrd240]

I have disconnected the voltage regulator. The battery stays at 12 volt without drainning.

 

Somehow, this also took care of my run on issue. The car now does turn off when I turn the key to the off position.

 

Ferhan

[duder280z]

I have disconnected the voltage regulator. The battery stays at 12 volt without drainning.

 

Somehow, this also took care of my run on issue. The car now does turn off when I turn the key to the off position.

 

Ferhan

 

If the voltage is at 12-12.5V while running, the battery is not being charged. Running voltage should be at least 13.5V. On my 280Z, the voltage meter shows more like 15.5V with no lights or accessories running. In order for the battery to recieve any charge the voltage has to be higher than it is at full charge(12.6V or so is full charge). If you keep running it, it'll eventually go dead and leave you stranded. If you replaced the regulator already, it must be the alternator going bad. I had an issue with an old honda of mine that was similar. I noticed something wrong, so I checked voltage at the battery and it was something like 18V. I jimmy rigged my multi meter so I could read it in the car and had to manually regulate it. If it went high, I'd turn everything on. When it went down I'd turn stuff off. It was ghetto, but I made it home without burning anything down. I actually ran the car like that for a few months till I got rid of it.