Battery Cut Off Switch Help

[HI WINDING MONZA]

Installing a Battery switch in the 1980 Monza , I 've run into a problem. It still runs with switch off.

I tried to disconect all the different wires to the alternator yesterday with it running, with no luck.

Some people online say to put a diode to the charging light or use a 4 lug Battery switch but I think that wont help either.

I have an Electric fuel pump and fan.

I did cut the pink wire over near the master cylinder that runs to the distributor power while it was running and that cut the power.

The problem is there are so many power wires under the hood, probally getting electrical feedback, it has me baffled.

If I get the 4 lug Battery switch, can I run that "pink" wire to it to kill the distributor? It only has a 20 amp limit on the small lugs.

It is ( was) a 151 car with rear wire defroster.


http://www.mgtoronto.com/pdf/Tech/ignition-run-on.pdf

http://www.dapa.org/images/b-1-alt.gif


http://cgi.ebay.com/ebaymotors/Taylor-1 ... ccessories

Doug in AZ

[speedphreake]

I'm assuming the battery is in the back. You need to run the alt main power wire from the alt directly to the battery. That way when you kill the switch, it kills the battery and the power being generated by the alt. On mine, I put a 150 amp circuit breaker next to the battery for the alt wire in case of a short.

[HI WINDING MONZA]

I did that allready , and it still runs when the switch is thrown . Doug in Az

[NixVegaGT]

Wow that is strange. I'll ask how my Brother's car is set up.

[spencerforhire]

2 possible reasons for the cut-off switch not working: The alternator has TWO red wires; normally, they join together in the harness. If you only sent one to the back battery, the other can still feed back. Also, if your car is stripped down for the track with no instrument cluster, you HAVE to install the diode in the brown alternator wire.

[Monzsta]

Your electric fan is likely the culprit, turning into a generator with the switch cut off. It may also be back feeding the alternator, allowing it to continue charging/energizing the system.

[NixVegaGT]

Huh. Good feedback guys. Good ideas. I'm going to pay attention in case this comes up for me too. Thanks.

[HI WINDING MONZA]

Got it finally figured out, the 80 cars have 3 wires attached to the alternator output. ( 2 ten guage , 1 14 guage )

The 2 10 guage wires( red) need to be together all the time for everything to work. 1 goes to the battery, the other to the fuse box with a fusible link attached.

Got a Taylor #1033 4 lug battery switch ( Had a 2 lug before) and attached the starter 2 guage cable to one large lug, the battery cable and the alternator output to the other large lug.

Run a 2" jumper wire from the Starter large lug to one of the small lugs on the switch.

Then disconnect the other 10 guage wire from the alternator output ( its the Fuse box feed )

Connect a 10 guage wire to the last small lug on the Battery switch and run it under the car to the feed wire to the fuse box.( cut it and leave on the fusible link and connect)

It Now shuts off the car when the switch is thrown!


Doug in Az