The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > LSx Swaps

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-20-2015, 11:08 AM   #1
LeesTruk
Registered User
 
Join Date: Mar 2015
Location: Manchester, CT
Posts: 433
TCC wiring question

I'm in process of under dash wiring for my LS swap, particularly the brake switch. I'm using a 3 position brake switch (1 n/o, 2 n/c ) from a '96 Firebird/Camaro. The 2 n/c switches will be for TCC and cruise. It's to my understanding that there will be B+ (ign. switched) to both of these switches and from the switches to the TAC (cruise pwr.) and the PCM for TCC. The question is, are these B+ sources for power or just 12v reference signals? Ultimately, the question comes to what gauge wire do I need to run?

I've got two neat factory pigtails that will plug into my fuse block. One looks to be 14 gauge, the other is 18 gauge wire. I'm not sure which to use for my wiring, although it would be safe to err on the larger of the two. Thanks

Lee
LeesTruk is offline   Reply With Quote
Old 10-20-2015, 11:12 AM   #2
Hart_Rod
*************
 
Hart_Rod's Avatar
 
Join Date: Apr 2005
Location: Pensacola, FL
Posts: 17,858
Re: TCC wiring question

When in doubt, always go with the bigger wire.....
Hart_Rod is offline   Reply With Quote
Old 10-20-2015, 04:49 PM   #3
BR3W CITY
meowMEOWmeowMEOW
 
BR3W CITY's Avatar
 
Join Date: Sep 2009
Location: MKE WI
Posts: 7,128
Re: TCC wiring question

I have yet to see a tcc/tac/pedal/switch etc or any of those units fail or fire due to a wire being too thin...but that being said, I wouldn't want to be the first to find out! Most of the wire in "modern" assemblies is around 16. Cheapy parts and 5v electronics will see 22-18awg. Also mind that if your putting it into an old enough truck, you may have a large amount of solid-core copper wire, which has a different laod carrying capacity than braided strand wire.

Going from solid to braided repeatedly and jumping wire gauges can actually CREATE a problem where one wasn't before due to varying levels of current capacity and impedence.
__________________
'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING

MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD
BR3W CITY is offline   Reply With Quote
Old 10-20-2015, 05:11 PM   #4
LeesTruk
Registered User
 
Join Date: Mar 2015
Location: Manchester, CT
Posts: 433
Re: TCC wiring question

BR3W, my truck is an '80 and its' wiring is copper strand. I know the brake portion of the switch is meant to carry a "load" when applying the brakes for brake light illumination. I'm pretty sure the PCM supplies the 12vdc to the TCC, through the trans. harness (4L60E). What I'm not sure of, though, is if the PCM receives the 12vdc through the independent fuse block, or if it passes through the n/c portion of the brake switch. Am I right in thinking that the switch is just a "trigger" for unlocking the TCC when the brake pedal operation "opens" the switch? If that is the case, then the wiring won't be carrying a heavy amp load, much like the working of a relay. Yes?

Lee
LeesTruk is offline   Reply With Quote
Old 10-21-2015, 12:19 AM   #5
BR3W CITY
meowMEOWmeowMEOW
 
BR3W CITY's Avatar
 
Join Date: Sep 2009
Location: MKE WI
Posts: 7,128
Re: TCC wiring question

Yes, its just working as a signal/trigger. Its all 12v, but the tail lamp circuit is pretty low amperage, less than 10iirc. The TAC and everything are individually powered, so its only using the switch for a "yes or no".
__________________
'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING

MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD
BR3W CITY is offline   Reply With Quote
Old 10-21-2015, 04:20 AM   #6
LeesTruk
Registered User
 
Join Date: Mar 2015
Location: Manchester, CT
Posts: 433
Re: TCC wiring question

Thank you, sir
LeesTruk is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:51 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com