How about the stock horn wiring? Does it go through a relay? Maybe I could just connect the stock horn, that uses less current, to my extra switch and run the airhorns from the steering wheel horn button.

 

Here is the schematic for the horn.

http://n8zcc.com/pics/HHR/HornSchematic.gif

 

Thanks Monster. So with 10 amps, I guess I cant run the compressor off the stock wiriing. So I am back to the drawing board. It seems crazy to have to run a high amp line from the interior fuse box or from the battery, though.

 

Well, I remember seeing a 50 amp feed feeding the underhood fuse box. Why can't you take your tap there?

The underhood fuse box feeds power to the interior fuse box/BCM by a 40 amp feed, so it would not make sense to tap there for the power.

 

That would be great-where is it? Also, the headlights draw a lot of current-what feeds them?

 

The under hood fuse box feeds the head lamps by a 10 amp circuit.

Look around the under hood fuse box, a 50 amp cable is going to be sizeable so you should be able to see it. I don't have any pictures of it's location, sorry.

 

I see that there are several fuses in the engine compartment fuse box of 30 amps. So the box itself can handle it. What about using a spade terminal to one of the empty fuse slots???

 

Unfortunately my schematics don’t show if or how the empty spaces are wired, sorry.

 

I am guessing that they must come from a main wire that can carry the maximum load of any fuse in the box. So, in theory I should be able to tap into any of the unused plugs. I am just a little apprehensive due to my previous problem after using the powersteering post (I lost power there for about a week, then it mysteriously appeared again).

 

I am getting ready to give up on these stupid airhorns. I took the car to the Chevy dealer for the antennal to be ordered, then asked him about a good power source. He suggested one of the empty fuse slots, like I suspected. But when I tried, it did not work either. Apparantly although there are 40 and 30 amp fuses in the box, they dont draw anywhere near the max.

I am going to see if I can find a low-draw compressor or I will abandon the air horn idea and just get some louder electric horn(s).