Wiring diagram review

BUG-E J · Feb 12, 2018

Bebop said:
You have a stock GM LS ECM I'm assuming.
It will ground the commands. You still need relays for fuel pump, fan 1 and 2. Use the same command for the trans fan if that's what you like.

Basically, send fused power to a distributing block.

From there you send fused power to each relay and then to each electrical device. That's your power circuit.
Then you send one general fused power to a switch board that will trigger the relays. That's your command circuit for the accessories.
With a stock GM LS ECM, command (ground IIRC) for your fuel, fan1 and 2 relays will come from the ECM. ECM needs to be directly connected to hot all times via power circuit and ign power via the command circuit.

Hope this helps, otherwise you can call me this evening after 8, I'll try to make it clearer.

To make it simpler on you, run it like you don't have an ECM doing **** and then add it in the mix.

Yeah those labeled wires are ground controls to a relay to energize the circuit on an ls. Like i said your trying to wire everything at once. Get your starter, alternator, stripper lights, radio, light bars, rock lights, horn, pa system, whatever figured out and drawn out nicely with one wire in diagram that reads to pcm. Then you can start tackling the other things. Whomever is cutting down your harness and flashing pcm can tell you what the rest does. You can have the program in the pcm changed to turn on your fans at a lower temp than factory and still do a high and a low if you wanna run 2 fans.

Dirt700 · Feb 12, 2018

I hate wiring, one of y'all is probably gonna make some extra cash

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Dirt700 · Feb 12, 2018

Re: Re: Wiring diagram review

BUG-E J said:
Yeah those labeled wires are ground controls to a relay to energize the circuit on an ls. Like i said your trying to wire everything at once. Get your starter, alternator, stripper lights, radio, light bars, rock lights, horn, pa system, whatever figured out and drawn out nicely with one wire in diagram that reads to pcm. Then you can start tackling the other things. Whomever is cutting down your harness and flashing pcm can tell you what the rest does. You can have the program in the pcm changed to turn on your fans at a lower temp than factory and still do a high and a low if you wanna run 2 fans.

Ok. Thanks for the help Jon

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Dirt700 · Feb 12, 2018

Re: Re: Wiring diagram review

Bebop said:
You have a stock GM LS ECM I'm assuming.
It will ground the commands. You still need relays for fuel pump, fan 1 and 2. Use the same command for the trans fan if that's what you like.

Basically, send fused power to a distributing block.

From there you send fused power to each relay and then to each electrical device. That's your power circuit.
Then you send one general fused power to a switch board that will trigger the relays. That's your command circuit for the accessories.
With a stock GM LS ECM, command (ground IIRC) for your fuel, fan1 and 2 relays will come from the ECM. ECM needs to be directly connected to hot all times via power circuit and ign power via the command circuit.

Hope this helps, otherwise you can call me this evening after 8, I'll try to make it clearer.

To make it simpler on you, run it like you don't have an ECM doing **** and then add it in the mix.

I may call you next weekend, I will be in bed by 8 tonight, my I go into work in the am

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Dirt700 · Feb 12, 2018

Re: Re: Wiring diagram review

Dirt700 said:
Ok. Thanks for the help Jon. I'm gonna have thermostat for fans, one on at 180, other at 200

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BUG-E J · Feb 12, 2018

Yeah man no problem. Biggest thing with wiring is its not as hard as it seems and a million ways to do it.

Bebop · Feb 12, 2018

You got it !

Except the ECM doesn't need a relay, and the trans fan will not be commanded by the ECM.
You need to run a separate (fused) wire from where you want directly to the relay.

If you want the trans fan to be running at all times, run a wire from the command fuse block to the relay command. You might add a switch to turn if off, or not.
If you want the trans fan to be running when the Ign is on, run a wire from the ign switch to the relay command. Or you could also run a wire from the fuel pump relay command to both fuel pump and trans fan relays, since they come on at the same time. Saves wires and no need for fuses.

Dirt700 · Feb 12, 2018

BUG-E J said:
Yeah man no problem. Biggest thing with wiring is its not as hard as it seems and a million ways to do it.

I'm hoping it will be easier once I'm actually pulling wires. Does everything need a relay, if so I got to have like 8 or 9?

Bebop · Feb 12, 2018

BUG-E J said:
Yeah man no problem. Biggest thing with wiring is its not as hard as it seems and a million ways to do it.

Oh yeah. There are many many ways to wire a rig.

I hate relays so I don't use them.
Fused power to everything, so everything runs from the kill switch.
Turn it on, everything is running. Start button. Vroom.
Turn the kill switch off when you're done. That's it.

Bebop · Feb 12, 2018

Dirt700 said:
I'm hoping it will be easier once I'm actually pulling wires. Does everything need a relay, if so I got to have like 8 or 9?

You only need relays for high draw stuff. Fans and fuel pump in your case. That's it.

BUG-E J · Feb 12, 2018

Bebop said:
Oh yeah. There are many many ways to wire a rig.

I hate relays so I don't use them.
Fused power to everything, so everything runs from the kill switch.
Turn it on, everything is running. Start button. Vroom.
Turn the kill switch off when you're done. That's it.

Bebop said:
You only need relays for high draw stuff. Fans and fuel pump in your case. That's it.

I run 1 80 amp relay for my fans and lights. 1 80 amp relay to feed my pcm which has a dedicated relay in harness for fuel pump. Turn my kill switch on and push button. I have 1 toggle switch that activates nitrous and 1 that activates lights. Its exactly what i wanted and works perfect. I dont like multiple switches and fuse blocks but its all in your prefrence.

Dirt700 · Feb 12, 2018

I haven't did this much drawing since kindergarten

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BUG-E J · Feb 12, 2018

Now your getting it cut down. I run jumpers between my relays to save wire also.

You really want me to confuse you i prefer cutting the ground off through switches and having power to loads......

Dirt700 · Feb 12, 2018

BUG-E J said:
Now your getting it cut down. I run jumpers between my relays to save wire also.

You really want me to confuse you i prefer cutting the ground off through switches and having power to loads......

Would you have hot wire directly to item being ran, but together ground wire pass thru a switch?

BUG-E J · Feb 12, 2018

Dirt700 said:
Would you have hot wire directly to item being ran, but together ground wire pass thru a switch?

Yes but thats not necessary dont confuse yourself its just what im used too dealing with so it makes it easier on me

hokie_yj · Feb 13, 2018

I'm glad this thread got bumped back up. It's getting close to time to start wiring my buggy. I've been meaning to sketch out a diagram for a while. It's been a slow night at work so here's my 3:00 AM buggy wiring diagram.

Batteries are dual Odyssey PC925s. The battery selector/disconnect is a Blue Sea 600a switch.
All battery cable will be 2/0 AWG welding cable except the charge wire will be 4 AWG. The fuel pump, radiator fan, ignition, etc. are fed by relays in the engine harness, but I'm going without relays on the rest of the loads for simplicity. I know a that's a pretty debated subject, but I'm confident it will be fine. Everything will be done with high quality components. The highest load will be the trans cooler fan at about 15a. The two light bars will be about 10a each, and the dome light probably not much more than 1a. The switch panel is a 12voltguy panel with ignition and push button start, winch controls, and 6 aux. switches.

I know it's been recommended in this thread to have the alternator charge wire on the battery side of the disconnect, and I understand why. The way I have it the alternator will still feed everything and the battery switch will really only be a disconnect, not an emergency shutdown. But the main ignition switch on my panel will drop out the relays in the engine harness for the fuel pump and the ignition system. It would be nice to have the battery switch for another emergency shutdown, but having the dual batteries made that seem to difficult to be worth it for me. I didn't want to fool with battery isolators and stuff like that. Plus the ignition switch and battery switch will be right beside each other on the console, so I guess there's really not a big advantage to having the battery switch be another shutdown.

Really my only other concern with this setup is that the engine harness gets it's constant 12V from the alternator stud through a fusible link. That's all well and good, except that when I turn off the battery switch I will lose the 12V constant for the ECU memory. I don't plan on using the battery disconnect much other than when parking the rig for extended periods. But something could always happen necessitating killing the batteries. My harness is an aftermarket standalone harness from Tilden Motorsports. I've peeled the loom back a few inches from the fuse/relay box and found where all the 12V constants are spliced onto the end of the wire going to the alternator stud. I've identified the ECU memory wire. I can cut it loose from the wire going to the alternator and run it directly to one of the batteries if necessary. I play an electrician at work, and I'm relatively confident in my ability to not butcher it up, but I just kinda cringe at the idea of hacking into a $700 harness unless it's absolutely necessary. So how big of a deal is it to have the ECU power killed by the battery disconnect that's going to remain on most of the time under normal circumstances. I know the ECU will have to relearn for a bit after having the memory power restored, but how big of a deal is that really? I know it may run a little off at first, but it should be a pretty short period of time shouldn't it? I've searched and searched trying to satisfy myself on this question, but I've never found a clear answer.

If you spot an issue, something I'm overlooking, or think I'm doing it just plain wrong speak up. I'm always open to help and constructive criticism.

Dirt700 · Feb 13, 2018

Good work Ben

hokie_yj · Feb 13, 2018

Making it look good on paper is the easy part. Haha.

hokie_yj · Feb 13, 2018

I€™ve already realized one mistake I made. I left out my rock lights. They will feed from the switch that currently says interior light, and the interior light will move over one slot. I'll edit the sketch later, but right now I'm going to bed. It was a long night.

ForMud · Feb 13, 2018

hokie_yj said:
I'm glad this thread got bumped back up. It's getting close to time to start wiring my buggy. I've been meaning to sketch out a diagram for a while. It's been a slow night at work so here's my 3:00 AM buggy wiring diagram.

Batteries are dual Odyssey PC925s. The battery selector/disconnect is a Blue Sea 600a switch.
All battery cable will be 2/0 AWG welding cable except the charge wire will be 4 AWG. The fuel pump, radiator fan, ignition, etc. are fed by relays in the engine harness, but I'm going without relays on the rest of the loads for simplicity. I know a that's a pretty debated subject, but I'm confident it will be fine. Everything will be done with high quality components. The highest load will be the trans cooler fan at about 15a. The two light bars will be about 10a each, and the dome light probably not much more than 1a. The switch panel is a 12voltguy panel with ignition and push button start, winch controls, and 6 aux. switches.

I know it's been recommended in this thread to have the alternator charge wire on the battery side of the disconnect, and I understand why. The way I have it the alternator will still feed everything and the battery switch will really only be a disconnect, not an emergency shutdown. But the main ignition switch on my panel will drop out the relays in the engine harness for the fuel pump and the ignition system. It would be nice to have the battery switch for another emergency shutdown, but having the dual batteries made that seem to difficult to be worth it for me. I didn't want to fool with battery isolators and stuff like that. Plus the ignition switch and battery switch will be right beside each other on the console, so I guess there's really not a big advantage to having the battery switch be another shutdown.

Really my only other concern with this setup is that the engine harness gets it's constant 12V from the alternator stud through a fusible link. That's all well and good, except that when I turn off the battery switch I will lose the 12V constant for the ECU memory. I don't plan on using the battery disconnect much other than when parking the rig for extended periods. But something could always happen necessitating killing the batteries. My harness is an aftermarket standalone harness from Tilden Motorsports. I've peeled the loom back a few inches from the fuse/relay box and found where all the 12V constants are spliced onto the end of the wire going to the alternator stud. I've identified the ECU memory wire. I can cut it loose from the wire going to the alternator and run it directly to one of the batteries if necessary. I play an electrician at work, and I'm relatively confident in my ability to not butcher it up, but I just kinda cringe at the idea of hacking into a $700 harness unless it's absolutely necessary. So how big of a deal is it to have the ECU power killed by the battery disconnect that's going to remain on most of the time under normal circumstances. I know the ECU will have to relearn for a bit after having the memory power restored, but how big of a deal is that really? I know it may run a little off at first, but it should be a pretty short period of time shouldn't it? I've searched and searched trying to satisfy myself on this question, but I've never found a clear answer.

If you spot an issue, something I'm overlooking, or think I'm doing it just plain wrong speak up. I'm always open to help and constructive criticism.

The only suggestion would be put a disconnect switch between the main bus bar and the winch. I'm just paranoid about having no way to shut off the winch if there a problem with the solenoids fusing.