Still have voltage with neg batt cable disconnected??

[Commander5993]

Hey all,

12 Volt systems I know, but I'm still pretty new to 24v DC systems.

So here's what happened:
Today I was doing the Doghead Under the Dash Starter Relay Mod. I disconnected the negative (which goes to frame/ground) battery cable on the front battery. Took everything apart inside, cut the wires, and was stripping the wires for the new connections, when suddenly to my surprise I got a spark!

So after this I got out my voltage tester, and sure enough the red wire had 24v. So I disconnected the cable between the front positive battery, to the rear (next to the firewall) battery's negative terminal. After doing this, didn't show voltage anymore.

I had to post this to ask, Is this Normal??!

I've never head of (nor can I wrap my mind around) disconnecting the negative battery cable, which should brake the circuit, but then still have voltage. Like I said, I'm still pretty new to the 24v system, so maybe this is why.

My next question is:
If I wanted to install a battery cutoff switch under the hood, which cable or cables would I have to install a switch into, to be able to cut all power to all systems?

Thanks Guys!

 

[doghead]

If you search the site a bit, you should find several threads where we've answered these things before.

 

[Commander5993]

Ok, I've done some searching, and from what I can find this apparently is "normal" for the system to do this. Which is still weird to me how it's possible.

Anyway, I have one more question. I tried to search and read through several threads but didn't find anything specific.

When I was doing the starter relay mod/upgrade, I noticed the two relay sockets next to it. I have read that one is for the exciter circuit on gen2, and the other is for the voltmeter.

The thing is, I only have one relay. The other socket is empty. Is this normal? From what little I have been able to find out about these in threads and such, and elsewhere, both sockets should have a relay plugged in, right?

Thanks!

 

[Warthog]

Because of the way the dual alternators are hooked up, you have to disconnect BOTH batteries to kill the circuit.



In a stock system, bothe relays are required for the system to work properly. One is for the voltmeter and the other is for the GEN2 exciter circuit.

 

[Commander5993]

System is stock except for GP resistor bypass.

Thanks for the confirm. I already have the relays on order along with some other parts. So once I get them, I'll go ahead and replace the one that is there, and plug the other into the empty socket.
Thanks Warthog!