Battery Disconnect Switch .... Help!

Battery Disconnect Switch .... Help! - 12/14/11 05:56 AM

Moving battery to the trunk. I'm not very versed in electrical. I see disconnect switches anywhere from 20 amp to 250 amp. What do I need and why? Street strip car, stock 1967 electrical system.

Posted By: MR_P_BODY

Re: Battery Disconnect Switch .... Help! - 12/14/11 06:24 AM

Quote:

Moving battery to the trunk. I'm not very versed in electrical. I see disconnect switches anywhere from 20 amp to 250 amp. What do I need and why? Street strip car, stock 1967 electrical system.

250 amp... the starter itself will draw near 100
thats short time but you have alot of other stuff
drawing all the time... also see if its constant duty 250

Posted By: Scamp408

Re: Battery Disconnect Switch .... Help! - 12/14/11 01:35 PM

I use this from ECH SW185 napa I think its the same as the moroso super duty 4 terminal one .Very heavy duty .

Posted By: Triple Threat

Re: Battery Disconnect Switch .... Help! - 12/14/11 04:08 PM

Bigger is better. Mine was meant for a industrial application with multiple batteries, I don't know what its rated at but its a lot.

Posted By: StealthWedge67

Re: Battery Disconnect Switch .... Help! - 12/14/11 04:39 PM

okay, I placed my order with Summit. I went with 1-guage cable, and the summit 250-amp waterproof switch.

My MSD is fed directly off the starter relay. If I'm thinking this through correctly, when you hit the disconnect switch at the back of the car with my ignition wired like this, it should shut the car down, correct?

Posted By: gsmopar

Re: Battery Disconnect Switch .... Help! - 12/14/11 05:56 PM

Quote:

250 amp... the starter itself will draw near 100
thats short time but you have alot of other stuff
drawing all the time... also see if its constant duty 250

I wired the starter in parallel on it's own heavy gauge wire independent of the kill switch. The disconnect switch kills power to everything else (including the starter solenoid). I bought the flaming river switch because the push/pull lever is easier to place than the larger twisting handle of the other switches.

Posted By: MR_P_BODY

Re: Battery Disconnect Switch .... Help! - 12/14/11 09:25 PM

Quote:

okay, I placed my order with Summit. I went with 1-guage cable, and the summit 250-amp waterproof switch.

My MSD is fed directly off the starter relay. If I'm thinking this through correctly, when you hit the disconnect switch at the back of the car with my ignition wired like this, it should shut the car down, correct?

UNLESS you have the alt out put wire is attached to
that same lug on the relay, then the ignition will
still be hot... if your alt wire goes to the battery
side of the master it will kill the engine

Posted By: StealthWedge67

Re: Battery Disconnect Switch .... Help! - 12/18/11 02:35 AM

I haven't made any of the changes yet, but today I yanked the positive cable while the car was running, and it kept running. Sooooo, how do I rewire the alternator, Mike?

Posted By: RobX4406

Re: Battery Disconnect Switch .... Help! - 12/18/11 04:24 AM

The small red wire from the MSD needs to be downstream from the cut off switch. That is the trigger or on/off wire for the box.

The big red wire that goes to the battery can be on either side of the cut off switch, preferably directly on the battery post.

I prefer a trunk mounted ford style solenoid and not running starter draw through the cut off switch.

Here are some diagrams.

Posted By: StealthWedge67

Re: Battery Disconnect Switch .... Help! - 12/18/11 04:42 AM

I've got it now. I'm just going to bring the alternator wire to the battery side of the disconnect switch (2nd diagram above).

Thanks-

Posted By: MR_P_BODY

Re: Battery Disconnect Switch .... Help! - 12/18/11 04:57 AM

Quote:

I've got it now. I'm just going to bring the alternator wire to the battery side of the disconnect switch (2nd diagram above).

Thanks-

You'll be set then