Ksths2

iTrader: (1)

Hey guys.
I had Brendan of LT1swap.com rewire my stock LQ4 harness and add the relays/fuses and OBD2 port etc.

This car is 100% stripped of all wiring and I just ordered a 20 circuit wiring harness. And i'm trying to decided whether to leave the engine wiring seperate from the fuse block or tie into as well.

I'm an experienced wiring guy but honestly never done anything this indepth before.

1) My immediate question is there is a thicker purple wire from the PCM loom that he has labeled "Starter" and according to him he says to will go to the your key switch and the other end has the small eyelet that goes to the solenoid, is this the wire that would come off the ignition switch thats labeled solenoid? (I'm assuming it is) basically its the wire that tells the starter to start correct?

2) I'm also running the stock alternator and I'm trying to figure out where you guys run the wire off the back of the alternator stud. Do you guys like to run it directly back to the battery or the main power stud on the starter? (BTW this car is a trunk mounted battery)

3) The grey 12+ fuel pump wire, would you guys tie this wire back into the fuse block or just go directly to the pump? This already has a fuse in the block that Brendan wired up for me.

4) Last question for now, what are you guys using for the TCC Brake switch to disengage the torque converter that goes onto the brake pedal? It needs 12+ signal when the pedal is NOT pressed and signal needs to be cut when brakes are pushed and needs to be 12+/hot when key is on as well.

These are really simple questions but they've got me thinking and second guessing myself so I need some clarity

-TheBandit-

iTrader: (1)

Yes this is the solenoid wire. When you apply 12 volts, the starter will crank.

Do you have a battery cutoff switch or plan to run one for NHRA or other racing? If so, the alternator needs a dedicated wire all the way back to the battery on the battery side of the cutoff switch so it will not keep the engine running from alternator power when the battery is cut out of the system. If you do not have a battery shutoff you can run it to the starter lug which will then connect to the battery in the trunk

If it already has a relay and a fuse, you do not need to tie it into any other fuse/harness; it can wire directly from there to the pump. Alternatively you might consider putting a fuel pump relay & fuse in the trunk closer to the pump so the power has a short run from your battery to the pump and you are only running signal-level current with a smaller wire size from the front of the car.

BP Automotive

iTrader: (3)

Unless you are running a high amperage ignition switch or push button starter switch you will need to take that purple wire to a relay. You can burn up an ignition switch quick, fast, and in a hurry if you are using just a standard switch.


Bandit, Your pigtail is on the way sir.

-TheBandit-

iTrader: (1)

I am pretty sure my '70 has a full current starter solenoid wire directly from the ignition switch. Is that not the case on late model vehicles? Wonder if I should add a relay as you're suggesting.

Thank you. Look forward to seeing it! I appreciate the speedy response and the willingness to do a small job like that.

BP Automotive

iTrader: (3)

Most older vehicles had a higher current ignition switch because they never came with a starter relay. When GM started equipping newer vehicles with the VATS system a smaller switch was utilized because a starter relay was integrated for the security system.

Ksths2

iTrader: (1)

that all makes sense to me

no this car won't have a battery cut off switch, it'll just be a lead sled crusier

Good info guys, thanks again!

TomM

iTrader: (56)

Use this, already wired up for you...

http://secure.ultracart.com/catalog/PSI/KIT-1002.html

T,

Ksths2

iTrader: (1)

VERY NICE! Thanks Tom!

bczee

iTrader: (12)

Many of the newer car/truck have the correct switch to use, they have the combo TCC/Brake Switch (like the one PSI is marketing).
I just used one from a 4th Gen Camaro.. it fit right in to my 71 Nova bracket and wired it up using the pigtails that goes to it. You can get them new at any parts store (O'Reilly, Autozone, Napa) or the nearest Pick and Pull..

Here is my thread and post #85 show how I wired it up and installed it.

BC

Ksths2

iTrader: (1)

Thanks BC, this is the same switch i used for my launch control (2 step) on my C5 but I couldn't remember what it came off of lol, thanks for reminding me