Fuse for connection near fuse box
 

I really blew it-a fuse that is. I just connected my air horns to the terminal next to the fuse box (near the jump start terminal). After a few 'toots' it stopped working. I checked with a test light and there is no power there anymore. There is a factory harness connected to it, and I was wondering what it powers (that is also not working anymore). Also, where is the fuse for that terminal? And can I up it to cover the horn, or should I get power from the jump start terminal?

Help
 

Any ideas, please. I am off tomorrow and may need to go to my Chevy dealer if it takes a special fuse or circuit breaker. Plus, I don't know if I am doing any damage driving the car with the mystery circuit not working (whatever is connected to that positive post).

It's very strange. This morning, the alarm I have hooked up to the power post is working again (but the airhorns connected to the same post aren't). The factory harness that is connected there seems to go into the firewall. (I can't really check because it is raining outside.)

I believe that the harness is for the power steering pump. I am now going to get wet and check for the fuse.

Lee; there is a BIG 50-amp fuse located at the battery terminals under the rear storage compartment:

http://www.socalhhr.citymax.com/i/Hi...ain_Fusesm.jpg

You might check that one first. If it's blown, you might need to go to the dealer to get one.

BTW- You should be running a relay for your air horns, never hook them up direct.

Hope it helps,

It is the strangest thing. At first when I checked the power to the post, it was dead. The next day, it was back again and my siren works again. I relocated the horn (of course I am using a relay and 20 amp fuse) to the terminal for jump starting the car, and it appears that the compressor is not working. It is odd, since the horn is brand new. It worked for the first 10 minutes then crapped out. To further check things, I just connected it directly to the car (with a fuse) bypassing the relay and switch, and the compressor didn't make a sound (I did get a spark).

You must have triggered a circuit breaker - and now it has reset.
Perhaps they have a breaker on the whole underhood box.
That's the only explanation I can come up with??

That's what I figured. Now I just have to get my air compressor replaced!

This is really killing me. This morning, my siren hooked up to the PS terminal worked. This afternoon, nada. Tonight I exchanged my airhorn compressor then decided to test it in front of the store. Nothing. I checked with a test light, and got no power to the PS terminal, the jump start terminal, or the open connections in the fuse box. The other day, these terminals all showed power. I checked the fuse by the battery, and it was good (when I pulled it, interior lights, door locks, etc wouldnt work). So what could be wrong?

If it is a circuit breaker, it may be fine in the morning. If not???

I haven't yet checked with a meter (I can tomorrow), but my guess is that the underhood block is "dead" unless the keys are on. I've read other owner's posts that they could not jumpstart a car from there, but had power back at the battery. Try again with your key on or at "acc" position.

And GET A RELAY on that compressor! :mad:

:thumb:

SoCal,

I will check too. And I do have a relay-I just used a wire with a fuse in it to test the compressor-I wanted to eliminate all other variables (switch, relay, and wiring). But, even with the car running, the alarm siren hooked up to the PW post was not working last night (it did in the morning). There must be some hidden circuit breaker somewhere in the system. (I even checked my test light on another car to see if the bulb was burnt out.)

If that fuse block wasn't working, though, nothing else in the car would work.

Well, I checked the fuse block and both posts with the engine running-and still no power. What feeds this block? And what feeds the jumpstart post? All of the accessories in the car seem to be working, so the block must be getting power!

Could have cooked a wire in the UBEC and now have an open in just that circuit. If I get a sec I'll pull a schematic thsi afternoon, pretty slow today I only have 2 more jobs to look at.

Thanks Aaron. What is the UBEC? Shouldn't it be able to handle an airhorn-less than 20 Amps. And why wouldn't the fuse blow?

There is a 50 amp fuse inline between the battery and the fuse block. It should be in the rear near the battery. Check that.

I already checked that the other day, and it is good. In fact when I removed it, everything in the car went dead (interior lights, radio clock, etc.)

What's next?

Do you have power across the EPS fuse? I think it is number 1 in the block, it is a J-fuse, either 30 or 60 amps.

Something is really crazy. I checked the fuse with a continuity tester and it is good. I checked both terminals and neither had 12 volts. I did this with the engine running. Yet, when I tried turning the steering wheel with the fuse pulled, there was no power steering. With the fuse replaced, the power steering worked again. How could this be with no power at the fuse block???

Pop the cover off the fuse and test with a test light at both terminals, then check a few of the other fuses just to verify power across them. I've seen those J-fues blow, but still allow power across them due to the funny design. When they blow the pieces are still contacting each other.

More wierd stuff. I checked this morning and everything is showing 12 volts-alarm siren working and everything. Even the jumpstart pole has power. But, when I tried connecting my airhorns to it, you could just hear a weak sound from the compressor, even when I bypassed the relay. Apparantly it does not have enough amperage. Next question-where can I tap in for power for the new horns? There are several empty fuse slots in the box-could I just attach a spade terminal and plug in to one? (Obviously I am running an inline 20 amp fuse). If so, does it matter which one?

Again, thanks for all the suggestions and help.

I am still hoping that somebody can give me a suggestion of where to tap into for power for my airhorns. Could I put a spade connector on the wire and hook into one of the empty terminals in the fuse box?

To be completely honest you may just wanna get so amp kit thick gauge wire and pick up power at the battery itself.

I was considering that, but it seems kind of ridiculous. Generally I am running wires from the front to the back for an amp. Now I have to go back to front for a horn. Shurly there must be one wire capable of the horn. Why can't the post for jump starting the car work? It should be a direct connection to the battery itself, right?

yes, i was under the impression you tried that already. You may be able to go to the alt as well.

I did try it and it didnt work-in fact, the entire post lost its power for a while. But, it SHOULD work, right? If it's purpose is to jump start a car, surely it should be able to power a horn. From what I read about problems jumping the battery, perhaps there is a wiring problem in its design.