I'm trying to locate a source under the dash of my 89 1500 a place to access 12v switched power. I haven't had a chance to under the dash and look yet. Since I don't have power anything in the truck, are there several switched sources open in one of the panels down there? I assume if since this is a GM product that there is a fuse panel and an aux panel down there. Is this a correct assumption?

Thanks for any help, from one electrical novice!

 

The radio, turn signals and A/C are switched. What do you plan to hook up to it? You can tie into these lines if you don't overload the fuse.

 

I'm just looking to ad a little 2" tach for when I haul my trailer to see how hard the engine is working. I have a panel under the dash that has many wht red grn markings with open spades, but I don't know what they would be for or if the only ones that will have + are the ones marked red.

 

Check them with a voltmeter to see which ones are controlled by the ignition switch. When you do hook up the tach, remember to put a fuse in the line unless those spades are already fused.