12v key-on power

[SnowDrift]

Is there a place under the hood to pick this up without splicing into something like the alternator wire?

 

[jrsavoie]

Should be something in the under hood fuse box. Use a double tap or put 2 wires in a connector

 

[SnowDrift]

I thought so too, but everything I tested showed hot all the time

 

[ak diesel driver]

You have a 95 right? What does it have for the underhood fusebox?

 

[dbrannon79]

iirc there is not much in the under hood fuse box that works off the key other than some of the relays. I had to tap into one of the wires in the harness and run that to a relay which provided a good power lead from the battery.

Something I have thought about doing is having this relay run to an additional fuse block under the hood so that I could have some extra switched power areas under the hood.

a fuse panel similar to this.

 

[Glagulator]

The pink wires to the GPR, or FFM or boost solenoid would work.
What are you using the 12v. for?
Any other 12v. ign under the hood I would not tap into.
Unfortunatly there is no auxillary 12v. ign. tap under the hood.
There are some in the convenience center in the cab.

 

[SnowDrift]

For an hour meter

Since I have a manual wastegate controller, would that one make the most sense?

Yes, 95 has the big fuse center on the driver side fenderwell with the mini and maxi fuses

 

[Glagulator]

Perfect.
The yellow wire at the boost solenoid is not a normal ground.

 

[SnowDrift]

So I can use the pink wire from this solenoid? Is there a Deutsch connector to fit this?

 

[MrMarty51]

So I can use the pink wire from this solenoid? Is there a Deutsch connector to fit this?

Then use that wire for the signal wire to turn on the relay to Your full on 12 volt fuse panel.
Turn on the ignition and that turns on the relay to power up Your auxiliary fuse panel.

 

[Glagulator]

The mate to the boost sol. conn. is 12162000.
Pigtails are - PT786 12167120, PT2373 88862292, AUVECO 23190
There are a few on the truck.
The underhood light has one.
U-pull-it - many GM cars and trucks.
All the connectors on your truck are GM/Delphi/Aptiv.

 

[SnowDrift]

Then use that wire for the signal wire to turn on the relay to Your full on 12 volt fuse panel.
Turn on the ignition and that turns on the relay to power up Your auxiliary fuse panel.

why not just run the hour meter right off this pigtail? Are you just suggesting to power up an auxiliary fuse box for future use?

 

[dbrannon79]

why not just run the hour meter right off this pigtail? Are you just suggesting to power up an auxiliary fuse box for future use?

That was what I was going to do. just for future use to have something under the hood for key on power.

 

[JMJNet]

F-SOL?

 

[SnowDrift]

What is F-SOL?

 

[Glagulator]

Fuel Sol fuse. Feeds the PMD and the FSO only.
I would avoid tapping into that circuit.

 

[SnowDrift]

You mentioned the yellow wire is not a normal ground. Are you saying that because it doesn't go straight to a body or engine stud?

 

[Glagulator]

It is a Pulse Width Modulated control ground from the PCM.

 

[jrsavoie]

It is a Pulse Width Modulated control ground from the PCM.

Are you talking about the fuel shutdown solenoid on the Injection Pump?

That's where I was thinking a guy could grab key on power.

So it would be a bad idea to run a wire from there to a relay?

 

[Glagulator]

SnowDrift is using the boost solenoid connector to grab 12v. ign.
He is using mechanical boost control, so no longer needs that conn.
The FSO would work for a relay trigger but I would stay away from
any IP circuits, there are other better choices.