How to find the right wire to the ingnition key?

[sifan]

http://www.pre-luber.com/installoverview.htm

I just bought the pre-luber. According to the instruction, the orange wire must connect to the ignition key such that there is always power when cranking. I notice my stereo looses power when the engine is cranking. Without the factory wire diagram, how do I find the right wire that the orange wire should connect to?

 

[Jim 5]

You could start by tapping off a keyed circuit in your fuse box....the descriptions of the circuits in your fuse box cover is an excellent place to start.

You're going to need a test light, which looks like a screwdriver with the head sharpened, a light bulb in the handle, a wire exiting the handle, and an aligator clip on the end of the wire.

Ground the aligator clip and start testing fuse terminals or alternatively piercing wires with the sharp end of the test light (that's what it's for). Find a circuit or wire through trial and error that causes your test light to illuminate in the "ignition on" position and you're set.

You likely won't need alot of current here. I didn't follow your link, but I'm assuming the orange wire runs a relay that in turn runs your pre-luber.

 

[sifan]

I know one of the fuse is labelled for accessory where the stereo and cig lighter are hooked up. When the ignition is ON without engine being cranking, the stereo does have power. My question is why the stereo loose power when the the engine is cranking. Does it mean this fuse for accessory is not good enough for the oragne wire since the instruction says the orange wire must receive power when engine is cranking?

 

[sifan]

The diagram on the web site indicates the orange wire goes to key. The ignition key can be at either ON or CRANK positions. But, under either position there should be power, right? The stereo receives power when the ignition key is at ON position, not at CRANK position. This makes me wonder that finding a fues that supply power with ignition ON is sufficient enough. Is my understanding flawed here?

 

[brianl703]

Ignition switches cut power to some circuits in the crank position. Usually the radio is one of those circuits.

One circuit that is never (that I've seen anyhow) cut off during the crank position is the instrument cluster. Find whatever fuse is for the instrument cluster and you can use that for your pre-luber.

 

[eljefino]

If you looked at your ignition switch schematic you'd see a contact that works in:

off
Accessory plus ignition
ignition only
ignition plus crank
crank only

"Ignition" as its finest definition is always available at the ignition module. Other stuff like the computer and fuel pump also get power during crank. IDK if you have an underhood fusebox as well as the passenger one but you should have an "IGN" master fuse you can tap.

The stereo, rear defroster, and other non-essential options are denied power during crank so the necessary stuff gets the most.

 

[brianl703]

You can get an "Add A fuse" fuse tapper thing from Pep Boys or Autozone. It's an easy way to add a circuit to a fuse panel.

 

[sifan]

Thanks to all.

I did use the "Add-A-Circuit" fuse tapper as you suggested last time on my aftermarket electrical gauges. The fuse tapper has max of 10A, which matches the rating of the pre-luber pump. But, according to the instruction the fuse tapper can only tap into 10A fuse. If the fues for the instrument is over 10A, then I can not use this particular fuse tapper. If this is the case, is there another clean way to tap into this fuse?

 

[Jim 5]

You should not be driving your pump off an add-a fuse. You can drive a relay off such a circuit, which relay will in turn send power to your pre-oiler pump.

 

[brianl703]

I doubt the instrument cluster fuse will be over 10 amps.

But in case it is, there is another type of fuse tapper made that slips over the leg of the fuse. Radio Shack sells them:

http://www.radioshack.com/product/i...origkw=fuse+tap&kw=fuse+tap&parentPage=search

The catalog number is 270-1204 and you'll need a female 1/4 quick disconnect terminal (also sold by Radio Shack) to connect to it.

You'll probably also want an inline fuse holder so you can have a separate fuse for the pre-luber.

Also, this fuse holder only works for the standard size plastic fuses, not the new "mini" ones.

 

[sifan]

Thanks again for the tips. I will need to dig into the factory service manual.

Jim 5 - The orange wire comes out of one end of the electronic control module, whose the other end connects directly to the pump. So, I am not trying to power the pump directly.

 

[Jim 5]

Sifan,

Sounds like the electronic control module has a relay or SCR internally. As long as you've got a beefier wire going straight from the battery to the control module and then another beefy wire from the module to the pump, you should be OK.

Once you've got this installed, I think we'd all enjoy seeing some pictures!

Good luck with your project.

Jim

 

[Chris142]

If you need power when cranking why don't you get the power from the terminal on the starter that has power when you turn the key?

 

[Jim 5]

I think think he needs a circuit that is live when starting and running.

 

[sifan]

I finally installed the pre-luber kit. The 10A fuse for the gauges unser the dash worked perfectly with the orange wire with a "Add-A-Circuit" fuse holder. Thanks.