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WagonCrazy
08-09-2017, 09:22 PM
I'm in wiring jail tonight...

Anyone know where the brown-with-red-stripe wire goes? it's the last one to wire up and now I have to get under the Nomad to figure out what wire that's for...(comes thru the firewall from the engine compartment somewhere).

7640

7641

Bluegrass Trifive
08-10-2017, 03:05 AM
By the label on your PCM it says it's flashed and pinned as an 02 Camaro which is very common. Looking at the pin outs for an 02 doesn't show them having a brown with red stripe wire, what was the wire harness originally from? If you can tell me that I probably can tell you where it would then land for the 02 Camaro PCM connector.

WagonCrazy
08-10-2017, 06:45 AM
Thanks Bluegrass. I sort of posted that more or less sarcastically last night. I've got the pinout diagram from LT1swap and have everything else accounted for. But this one wire is not called out for the PCM (by its color...as you correctly mentioned) and it was put in by a previous owner prior to me doing this whole swap, and it went to pin 85 of a relay. I just need to jack up the car and get under it and see what this wire goes to in the engine compartment, then figure it out.

I started with a previous owners attempt at rewiring for this LS1, and then ripped it all out, changed the location of the PCM and EZWiring fuse panel, added more relays, circuit breakers,etc.
So kind of started over with the wiring and am figuring every circuit out....one by one...so that I understand what I'm doing.

It's a mental thing (wiring in general). Mostly not to get distracted with ANYTHING ELSE while I'm working on it...so that I don't screw something up due to distraction (which is the primary cause of my follies). All is well here in SoCal though...just want to get this Nomad to a point of starting it up SOON.

Bluegrass Trifive
08-10-2017, 06:52 AM
Thanks Bluegrass. I sort of posted that more or less sarcastically last night. I've got the pinout diagram from LT1swap and have everything else accounted for. But this one wire is not called out for the PCM (by its color...as you correctly mentioned) and it was put in by a previous owner prior to me doing this whole swap, and it went to pin 85 of a relay. I just need to jack up the car and get under it and see what this wire goes to in the engine compartment, then figure it out.

I started with a previous owners attempt at rewiring for this LS1, and then ripped it all out, changed the location of the PCM and EZWiring fuse panel, added more relays, circuit breakers,etc.
So kind of started over with the wiring and am figuring every circuit out....one by one...so that I understand what I'm doing.

It's a mental thing (wiring in general). Mostly not to get distracted with ANYTHING ELSE while I'm working on it...so that I don't screw something up due to distraction (which is the primary cause of my follies). All is well here in SoCal though...just want to get this Nomad to a point of starting it up SOON. Gotcha I feel your pain. No fun to follow someone else on that kid of thing!

WagonCrazy
08-11-2017, 12:18 PM
Turns out, that brown-with-red-stripe wire goes to a Backup Light switch mounted within the T56 transmission. That switch has 2 wires coming out of it...both are brown-with-red-stripe in color. One of them is cut short and has a connector set up for grounding it to the transmission case.

7642

So that means the previous owner intended to have the backup lights operating via a "ground" signal to a relay. (Which is why the other end of that wire was label as pin 86 on a relay)
So I drew out what I determined would be the appropriate circuit design, then tested this by hooking up the wires to a 12 v source and it worked as planned...( with the actual backup light switch throwing a ground signal at the relay to activate the lights).
Simple diagram for anyone who wants to know...

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chevynut
08-11-2017, 01:31 PM
You don't need a relay for the BU lights, and I wouldn't use one myself. I'd just switch the 12V with the BU light switch. A lot simpler, fewer parts. Just run the "ground" wire to a fuse (switched 12V), and the other brown/red wire to the backup light wire.

55 Rescue Dog
08-11-2017, 03:26 PM
You don't need a relay for the BU lights, and I wouldn't use one myself. I'd just switch the 12V with the BU light switch. A lot simpler, fewer parts. Just run the "ground" wire to a fuse (switched 12V), and the other brown/red wire to the backup light wire.
Only if the switch is rated for the back-up lamp current, which if not the relay can handle the power for sure.

chevynut
08-11-2017, 03:45 PM
Only if the switch is rated for the back-up lamp current, which if not the relay can handle the power for sure.

Just about any switch can handle the miniscule current of a pair of backup lights. The 1073 bulb used for stock backup lights are only about 23 watts, or 2 amps apiece for 4 amps total. Surely the T56 switch can handle that. And if using LED bulbs it's about 1/10 of that.

55 Rescue Dog
08-11-2017, 03:56 PM
Just about any switch can handle the miniscule current of a pair of backup lights. The 1073 bulb used for stock backup lights are only about 23 watts, or 2 amps apiece for 4 amps total. Surely the T56 switch can handle that. And if using LED bulbs it's about 1/10 of that.
So I'm guessing your car doesn't have, or need any relays, and you just run big wires, and switches to every device?

chevynut
08-11-2017, 04:45 PM
So I'm guessing your car doesn't have, or need any relays, and you just run big wires, and switches to every device?

There you go again with your BS. Did I say you never need a relay? No, I didn't, but as usual you try to twist and distort what people say and put words in their mouths. I have relays where I NEED them.

So I'm guessing your car has relays everywhere, even where they're not needed and you just run small wires and use relays for every device? :D

You don't need a relay when the load is small and a switch can handle it. You use relays where you NEED them, either for logic functions (such as AND/OR) or to carry high loads. The backup light switch on a T56 is meant to break the circuit to the backup lights, not to run a relay. That's how it's wired on cars that have them because the load is small and the switch can handle the current. And with LED lights you surely don't need a relay.

http://www.bionicengineering.net/media/backup_switch.JPG

55 Rescue Dog
08-11-2017, 05:18 PM
There you go again with your BS. Did I say you never need a relay? No, I didn't, but as usual you try to twist and distort what people say and put words in their mouths. I have relays where I NEED them.

So I'm guessing your car has relays everywhere, even where they're not needed and you just run small wires and use relays for every device? :D

You don't need a relay when the load is small and a switch can handle it. You use relays where you NEED them, either for logic functions (such as AND/OR) or to carry high loads. The backup light switch on a T56 is meant to break the circuit to the backup lights, not to run a relay. That's how it's wired on cars that have them because the load is small and the switch can handle the current. And with LED lights you surely don't need a relay.

http://www.bionicengineering.net/media/backup_switch.JPG
Assuming that they are LED's, and not 100 watt back-up lights which would be awesome. No BS

WagonCrazy
08-11-2017, 09:42 PM
Ok guys...I get both your direction here.
I'm going to leave this one wired with the relay because 1) it was already there in the fuse panel and 2) wiring it as CNut suggests means 2 wires (total) passing thru the firewall instead of 1 as it's wired now. Normally, that wouldn't be a big deal but I already have nearly 70 wires passing thru now just for the engine-to-PCM stuff and the few other wires needed for the engine-to-gauges. So it's getting tight in that spot.
CNut...I get what you're saying in your solution, and yes...that would work (to avoid the relay). Since it was already wired for the relay, I just chose to finish it up by putting that ground wire into pin 86 on the relay.
Definately value your electrical engineer perspective on this though. I'm learning as I go...

Now I have to see if I can get LED backup lights for a 57 Chevy. I like that option over the normal bulb style...

Onward!

chevynut
08-12-2017, 12:44 PM
Assuming that they are LED's, and not 100 watt back-up lights which would be awesome. No BS

The stock backup lamps are 25 watts each, as I already explained above, and a fraction of that (about 2.5 watts each) if they were LEDs. What moron would put 100 watt bulbs in the backup light sockets? :D

And besides, I'm guessing that BU switch can handle as much current as a relay. It probably CAN handle 100 watts.

Paul, are you sure your car can handle all the extra weight of those unnecessary relays? :D

55 Rescue Dog
08-12-2017, 03:17 PM
The stock backup lamps are 25 watts each, as I already explained above, and a fraction of that (about 2.5 watts each) if they were LEDs. What moron would put 100 watt bulbs in the backup light sockets? :D

And besides, I'm guessing that BU switch can handle as much current as a relay. It probably CAN handle 100 watts.

Paul, are you sure your car can handle all the extra weight of those unnecessary relays? :D
Congrats, I'm pretty sure that you will win the trophy for the heaviest Pro-street Tri-five ever. I=E/R
So what if you could see better with 200 watts of LED lights with only 1.6 amps of current which would be useful, instead of 4.16 amps with only the dim glow of 50 watts.

WagonCrazy
08-12-2017, 09:40 PM
Just did a google search for 1957 chevy led backup lights and NOBODY MAKES THEM. Plenty of molded backup light assy's for 1955 and 1956 chevys, but nothing for a 57. Wierd...
Guess I'll just stick with the filament style bulb for now....and swap to an LED bulb later on if need be.
For the absolute lack of time those lights will be on, I think I can safely bypass the expense of anything more than standard (now old fashioned) filament style bulbs.

Of course, I'm already over budget (and overweight) by one $8 Relay now... :p

chevynut
08-13-2017, 09:25 AM
Just did a google search for 1957 chevy led backup lights and NOBODY MAKES THEM.

All you need to find is a single filament replacement LED bulb, it doesn't have to be made for a 57 Chevy.

Here's one possibility that they say is for a 58 Chevy BelAir. They don't go back to '57 but I'm pretty sure it's the same, or equivalent.

https://www.superbrightleds.com/moreinfo/back-up-light-bulb/1156-led-bulb-w-stock-cover-36-smd-led-tower-ba15s-retrofit-car/1686/

There are many other options for other car backup/turn/brake lights on the site. All you have to get is the correct base and wattage or lumens you want.

https://www.superbrightleds.com/search/tail-brake-turn/backup%20lights/filter/Base_Type,1156,1,40:

chevynut
08-13-2017, 12:27 PM
Here's another one that should work, and it's probably available locally:

https://jet.com/product/detail/7e3a6ae845544e19b6ca0f50d5c1b57c?jcmp=pla:ggl:JD_d ur_Gen_Automotive_Parts_Accessories_a3:Automotive_ Parts_Accessories_Automotive_Lighting_Replacement_ Light_Bulbs_a3:na:PLA_785913096_44722408487_aud-320230129885:pla-292020578050:na:na:na:2&code=PLA15&pid=kenshoo_int&c=785913096&is_retargeting=true&clickid=a1466905-63aa-45ca-b253-1f3879471222

WagonCrazy
08-14-2017, 06:55 AM
Those will do the trick Laszlo. Thanks for doing the legwork to find them and posting the links.