Which Battery Disconnect Switch do i need?

[TrickFlow]

Im running the wires in my car, and realized that before i go any further, i need to order my switch. ill be mounting it behind the lisc. plate, and before i start cutting cables, i want that mounted there first. I figured i would just need a regular summit switch, but upon looking, there are several to choose from... these are the 2 im looking at:

MOR-74101 $39.88
Estimated Ship Date: Today


Brand: Moroso
Product Line: Moroso Battery Disconnect Switches
Switch Actuation: Rotary (turn)
Continuous Amp Rating: 175 amps
Surge Amp Rating: 1,000 amps

And:
--------------------------------------------------------
MOR-74100 $29.88
Estimated Ship Date: Today


Brand: Moroso
Product Line: Moroso Battery Disconnect Switches
Switch Actuation: Rotary (turn)
Continuous Amp Rating: 20 amps
Surge Amp Rating: 125 amps



Im running a 1000 amp battery, an aftermarket ignition (MSD or Crane) 2-10" subs and a small amp. i dont know which of these would make a difference if any, but i dont mind spending the extra 10 bucks for insurance if i need it.

 

[blown1989saleen]

I use the first Moroso switch you have listed

 

[TrickFlow]

Anyone else have an opinion before i click "order" on this thing?

 

[TrickFlow]

I use the first Moroso switch you have listed

Ok, i just called and asked someone about it, and they said i needed the one with the alternator cutoff as well... said if i dont get the one with the ALT cutoff, it will just drain my battery. any truth to this?

 

[TrickFlow]

Actually, let me re-type the second question. Does anyone know, if on a foxbody, whle the car is running, if you hit your disconnect swicth, will the car remain running? my buddies camaro stays running because he has a 1 wire alternator, but i dont know if the same holds true on a stang.

 

[jerryD]

to be NHRA or NMRA or whatever legal, it has to kill the car when you flip the switch.

 

[blown1989saleen]

Ok, i just called and asked someone about it, and they said i needed the one with the alternator cutoff as well... said if i dont get the one with the ALT cutoff, it will just drain my battery. any truth to this?

thats the switch I use and my car shuts off when the switch is cut off, as said to be legal at the track it must be visable and MUST shut the motor off when cut off, its all in how its wired.

 

[TrickFlow]

grat, so i have to wire the alternator all the way back to the switch as well... grrrr simple projects always turn into this crap for me

 

[blown1989saleen]

grat, so i have to wire the alternator all the way back to the switch as well... grrrr simple projects always turn into this crap for me

yes, if you want the switch to shut the motor off. run the alternator to the same side of the switch as the battery positive cable, run the solenoid positive to the opposite side of the switch. Is the battery in the trunk?

 

[TrickFlow]

Is the battery in the trunk?

Yeah, its in the hatch, i havent started running the wires as planned yet, i had a heck of a bender this weekend.

 

[jrichker]

Some advise on your rear mounted battery that will save you grief...

Rear mounted battery ground wiring. Follow this plan and you will have zero ground problems.

One 1 gauge or 1/0 gauge wire from battery negative post to a clean shiny spot on the chassis near the battery. Use a 5/16” bolt and bolt it down to make the rear ground. Use a 1 gauge or 1/0 gauge wire from the rear ground bolt to a clean shiny spot on the block.

One 4 gauge wire from the block where you connected the battery ground wire to the chassis ground where the battery was mounted up front. Use a 5/16” bolt and bolt down the 4 gauge engine to chassis ground, make sure that it the metal around the bolt is clean & shiny. This is the alternator power ground.

Crimp or even better, solder the lugs on the all the wire. The local auto stereo shop will have them if the auto parts store doesn't. Use some heat shrink tubing to cover the lugs and make things look nice.

The computer has a dedicated power ground wire with a cylindrical quick connect (about 2 ½”long by 1” diameter. It comes out of the wiring harness near the ignition coil & starter solenoid (or relay). Be sure to bolt it to the chassis ground in the same place as you bolted the alternator power ground. This is an absolute don’t overlook it item for EFI cars

 

[04sleeper]

You could always run the excitor wire to the switch with a relay or diode. Then when you cut off the battery it would cut off the alternator as well.