locating a live + wire when ignition is hot

[shesha]

Hi there

Any one can give me directions on how to locate a live + wire when ignition is hot on a K 2500 chevy 1997, I know basic electrics, but just need some guidance on this before I start blowing up fuses.

I have a 12V test light and digital meter, I currently connected the wire to the Ign fuse in the main fuse block but that did not work, since the current kept flowing even with the key out of the ignition, I was thinking of placing it on the AUX A or AUX B studs of the fuse block in the engine compartment that could be the trick.

Any help would be apprieciated.

[SpitAndDirt]

what are you trying to do first? Use your multimeter, when probing wires under the dash. You do not want to deploy an airbag because you caused a short to ground by using the test light. Second, your A and B terminals in the engine fuse box are there so that you can connect up accesories to them. They are hot all of the time. I use one of mine for my amplifier power wire. People hook up CB's and other work related devices to them. Other than that, I don't know what you are trying to do. -Chris

[shesha]

hi there chris

I am fixing a flexalite monster fan on the truck, it requires that a live + wire be hooked when ignition is on.

So the fans are activated only when the ignition is hot.

[Cadillakin'98]

I'm kinda confused....are you looking for the wire that is only hot in the CRANK position ..............or hot in the ON and CRANK positions...... or hot in ACC, ON, & CRANK??? ........Anyways, I recently redid my alarm on my '98 which I believe is same color codes as yours. If so there is a thick yellow wire that is only hot in CRANK position ............BE CAREFUL......... not to cofuse this w/ the air bag wires housed in a thick yellow tube that looks like the ignition wire (for would-be-thieves I'm guessing, not a bad idea) There is a thick pink (looks more like a dull red) wire that is hot in ON & CRANK, and I think a couple of others are hot in ACC, ON, & CRANK. Definantly check with a multimeter first, but hope this helps.

[ponchonutty]

Yes, you can use either white or pink wires from the ignition. If you are using a voltmeter, ground one lead to the chassis on the truck and then probe the other at any wire you are testing. MAKE SURE TO USE A HEAVY DUTY RELAY off of the battery though when hooking up the fan. Those fans require a lot of juice so you need to make sure to isolate the power source away from any wires you want to use to trigger it. That way you will not have the problem of blowing fueses or melting wires/ignition switches. Also, make sure to use appropriate sized wires and fuse all wires when doing the install.

[shesha]

hi there,

Yup, I am looking for a + wire that is hot when the ignition key is turned in the on and crank not accy.

The hook up point will be the main fuse box in the engine compartment, I have a a fuse tap pin that I have hooked up to the fuse of the electric fan, I just need to locate which fuse in the fuse box is hot when the ignition is turned in the on and crank position and is not hot when in the off and accy position.

Any ideas how I can use a multimeter to determine which fuse would be the correct one, tracing method.

Please do not forget that am not very well versed with electrics yet, have blown a couple of fuses already

[shesha]

Actually come to think of it just by accident I was checking the flexalite website on the monster truck electric fans, it so happens that they have some issues on the fuse housing that are supplied with their fans, luckily enough the truck was not moved after connections only tested at home, now I have to wait for them to dispatch the correct fuse housing so I dont end up in smoke one day.

You would think they would pay attention to something like this more seriously.

http://www.flex-a-lite.com/auto/html...r_warning.html

Coming back to our question, instead of wire we will use the fuse slots in the fuse box engine compartment, now anyone can identify which one is hot when ignition is in the on and crank position and off in the off and accy position.

In the event locating a wire will proceed as per your last instructions.

[Jeremy-WI]

On your 97 chech the wire harnesses coming from the under hood fuse/relay center, there should be a brown wire with a connector on it taped to a harness, I'd use this wire to trigger a relay for your fans power. Just read the last post, the trans fuse should do what you want

[shesha]

any specific reason why you would use that wire?