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2008 Chevy express no horn relay?

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Old September 18th, 2019 | 11:01 AM
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Default 2008 Chevy express no horn relay?

I’m working on a 2008 Chevy express 3500 and I haven’t had a horn since I bought the thing (used). So far I checked the fuse (it’s good). Pulled the wire at the horn (no voltage when horn is pressed). Pulled the air bag and checked the contacts to make sure they weren’t dirty (they make contact. I only tested with a continuity tester though not voltage for this test). And now I’m looking for the relay. I can’t find it anywhere. None of the relays are labeled for horn or PCB (I read this elsewhere that it may be labeled PCB). If anyone can direct me in the right path I would greatly appreciate it.... also it’s a plain work van with no Fob. Manual locks. So I cannot check the horn by clicking on the lock button like I’ve read elsewhere.
thanks in advanced for any help
Old September 20th, 2019 | 4:18 PM
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https://dan.berladyn.online/gm/gmt610-uo5-dual-horns/
Old October 13th, 2019 | 3:26 PM
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I have tested the wires under the airbag for voltage and I’m getting no power to the wires that are suppose to make contact for the horn... also I’m trying to read the schematic. It doesn’t tell me where the relay is located..

one more thing. Taking a deeper look into the schematic. I assume the wires for the horn under the airbag are suppose to be ground? Not 12v live?

Last edited by Tony vanore; October 13th, 2019 at 3:34 PM.
Old October 13th, 2019 | 4:43 PM
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Black should be ground, and Orange should be positive.

Originally Posted by Tony vanore
It doesn’t tell me where the relay is located..
What do you mean?
It says underhood fuse block, Relay K5
Old October 13th, 2019 | 5:21 PM
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When I get a chance. I’m gonna pop my hood and check. My fuse box is labeled 1-100ish. I didn’t know there was any lettered ones. Ty
Old October 13th, 2019 | 5:37 PM
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The underside of the fuse box lid usually has a diagram with each part labeled.
Old October 13th, 2019 | 6:13 PM
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this is the fuse box I have under my hood. According to this website only the 08-09 vans have this box. The only one labeled for horn is fuse 43. None of the relays say they’re for the horn.
Old October 13th, 2019 | 6:35 PM
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Like I said, you need to check the sticker on your actual fuse box, or the owner's manual. Not your smartphone.

Since, the schematic says it's a "PCB relay" , that probably means that it's not visible, and probably not user replaceable. You should check it externally.

Apply ground to the tan (TN) wire (pin H3 on the fuse block). Dark green wire (D-GN), which is pin B4, should get 12V. I think the pins on the connectors are labeled.
Old October 22nd, 2019 | 6:49 AM
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Originally Posted by mountainmanjoe
Like I said, you need to check the sticker on your actual fuse box, or the owner's manual. Not your smartphone.

Since, the schematic says it's a "PCB relay" , that probably means that it's not visible, and probably not user replaceable. You should check it externally.

Apply ground to the tan (TN) wire (pin H3 on the fuse block). Dark green wire (D-GN), which is pin B4, should get 12V. I think the pins on the connectors are labeled.

This is the fuse box in my van. I don’t see a horn relay
Old October 22nd, 2019 | 8:27 AM
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Hm I guess they omitted the information. In that case you can find it on
https://www.gmupfitter.com/pages/body-builder-manuals

It's a PCB relay like I thought so test like I mentioned.



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