School bus. Need help

[Jameslinx]

I know this is a little outside the realm of what most of you guys deal with. Deft is for me. I'm a bus mechanic in jersey, I've got a school bus that the radio just quit on the driver yesterday, j swapped the Hu out and no I'm having an issue with my speakers. I can hook my speakers up, they work, but when I turn off the bus, kill power the hu, and turn it back on, they don't work, if I disconnect the wires and re connect they work fine. Am I looking at a ground issue?

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[fasfocus00 5,000+ posts]

speaker wire is probably pinched somewhere. try to isolate it to which speaker.

 

[Jameslinx]

Ok, I left work so I am able write a little more.

swapped HUs, I can hook up most of the speaker wires without and issue. i get to the green positive and white positive which share a terminal on the harness into the bus and they dont produce sound if i hook them up individually. When i hook them up when the rest or any of the wires are hooked up, i lose sound and have to disconnect and reconnect ALL speaker wires to get sound back. if i leave them unhooked and hook everything else up i get audio, I can get audio just by hooking up a right side speaker wire and a left side speaker wire. the speakers on a bus i believe run in a constant circuit. there really is no left rear right rear speaker, as far as i can tell theres one main power wire running the length of the right side and one running the left side with wires tapped into that for each speaker, 4 per side. right speaker wires run right, left run left, makes no matter if i hook up front or rear.

When everything is hooked up i will have audio. I hook everything up while the key is in ACC and once im hooked up i turn the bus off, let it sit for a moment then move to the start and on position and i have nothing until i disconnect all speaker wires and reattach them. i lose audio every time i turn the bus off and on again. hu has power and memory after i turn the bus off, i dont lose that. just audio until i disconnect and reconnect speakers.

Never encountered anything like this and ive installed dozens of car and truck stereo systems...

hope someone can help. back to work at 9am tomorrow to try and figure it again so anytips for me to use by then would be greatly appreciated.

 

[CrossoverOre 10+ year member]

what ohm are the speakers. most decks only like to run 4 @ 4 ohms. also does the bus have a p/a system and does that go through the stereo or an add on.