moving the battery to the trunk with the moroso super duty cut-off switch.....the question is: how does the alternator charge the battery now with the wiring done the way instructions say to hook it up? is it safe to run a wire from the alternator to the positive post on the fender for this purpose? i wouldn't think so but i'm not sure. any help is appreciated.

 

ttt

 

When I relocated my battery, I ran the positive cable to the post on the starter soleniod and left the original battery cables intact. I haven't even cut off the old batt. terminals yet, just taped them up and have had no problems.

 

did you put in a big battery? i would think if the battery cables are still hooked up, they aren't doing anything except hanging there being inactive. it's not really a big problem, just curious if the battery will be charged by the alternator if relocated to the back.

 

What I did on mine is run the wire from the battery to a distrbution block (like the ones used for big auto stereo). And then I ran the wire from the alternator to the block also. Much better connection than taping them up. HTH

Joe

 

Well technically in order to be fully legal for racing, you have 2 options with the alternator output: buy painless' high amp relay and use it inline of the output wire so it breaks the connection.

Or you can run another wire back to the battery side of the switch from the alternator. This is what Im doing.

Those are the only 2 ways to be fully legal. NHRA says the cutoff switch must cease all electrical functions.

If you just connect the alternator to the cable coming up front, when you flip the switch, the alternator will continue to power the whole car and the motor.

 

Thought id relay some useful info, I just spoke with painless, and that relay you are speaking of does not work for a master disconnect switch. It is only used to cut off the alternator from the power system, not to cut off the power completely.

They are however coming out with a remote mount master disconnect switch in the next quarter he says, that will be a solenoid you mount inline of the main positive wire going up front, and then run a small low voltage switch to control the solenoid.

Just thought youd like to know before you order that relay and fry it when you use it.

The way I will be doing it is I have two wires coming up front, one will go directly to the starter, the other to the distribution block on the fender. Then the alternator wire will also go directly to the starter so that it will be connected to the battery to charge. Then the switch will be mounted inline the wire going to the distribution block so it will cut off everything, since the alternator isnt powering the car directly. Hopefully this isnt too much jumping around front to back to power the car good.

 

yes, that's how i'm wiring it up also......the only thing i was pondering was the instructions call for 10 ga. wire to the alternator to the switch, i was unsure whether that is sufficient enough to carry the charge to the battery. thanks for all the replies.

 

I think 10ga is too small. I have existing 4 ga going back there for my stereo, so I am going to use 4ga for it.

 

The reason it wont work is because it is not a CONTINUOUS duty solenoid. When you have the power on, there is current going through it constantly, like close to 250 amps consistantly. The solenoids you can just buy now that are rated to that much amperage arent continuous duty, they are made to switch on and off, like the solenoid on a starter, there is not power going through it constantly, that is why it will fry.

Secondly, why would you run the relay on the alternator and a mechanical master disconnect switch? This is only for 100% race cars where the alternator for some reason needs to be totally disconnected in certain situations or something like that, that is how painless explained it to me.

Instead of taking this from me, call painless and ask them, he explained it much better.

By the way, the part # on the new remote disconnect switch coming out is 30204. (Painless)

 

There's not 250 amps going through the switch. Your alternator cant even put that many out.

Painless makes a HIGH AMP relay to use to disconnect the alternator when the battery is switched off using the switch in the back of the car. You splice it inline of the alternator output, if you think it cant handle a continuous high amperage rating, you are kidding yourself. If it couldnt handle the continuous amps, it wouldnt work. Why do you think that relay costs 70 dollars? Because it can handle the high continuous amps.

You obviously have some research to do on this topic. In order to be fully legal for racing, you need to kill the alternator somehow. Alternators are self sustaining after they first kick on. Straight from the rule book section 16 8:4 :
"This cutoff switch must be accessible from outside the car body, and must stop all electrical functions including magneto ignition."

The alternator WILL keep the car running, you need a way to kill it. The only 2 ways to do it are to use painless' relay to cut the output when the switch is pressed, or run the output to the battery side of the switch.

 

Yes, but, if the alternator is not connected directly to the power that runs the coil, it is not powering the engine directly.

IE, if you run the alternator directly to the battery, nowhere else but the battery. Then, have the wire coming from the battery to the distribution block, and have that wire switched, when it is off the alternator would still be trying to charge the battery, but since that is off the engine will not run.

And I know the alternator does not put out that many amps, but a battery will. All I know is (forget about the amps), it is not continuous duty and according to painless will not work as a disconnect switch, I have no idea why they would tell me that if it isnt true, since i was going to order it then if it wouldve.

Look at this link, this is how the wiring is set up in my car.
http://www.geocities.com/jonaddis842...ingdiagram.JPG

By the way, im not just arguing with you to make enemys, i just know that i am right, and you are probably right too, but I dont want people to get the idea you can use that relay solely as a master disconnect switch.

 

I never said you should just only use only just the relay as the master disconnect. You have to use the disconnect switch and one of the options listed above.

God. Is that not what I just said 7 posts up?