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Tommy 1 · 08-06-2022, 12:35 AM

Don't ask me how but I hooked my starting battery backwards. Now when I turn on the key nothing happens. Will not start and all dash stays blank. Even when I push the battery boost button I get absolutely nothing. What did I blow? This is a 2005 winnebago voyage with the gm 8.1. Thanks for any thoughts or advice.

MrMark52 · 08-06-2022, 05:12 AM

Get yourself a voltmeter and the chassis wiring diagram and start making measurements.

Did you get any short term arcing when hooking up the battery backwards? If so, and then it quit - it’s probably a fuse somewhere (although fuses don’t care which direction current flow is).

Chassis wiring diagrams as well as others for the Workhorse chassis are available to download. Search for posts by Ed Gray where he gives a link.

99dart · 08-06-2022, 07:28 AM

Keep your eyes open for one of these circuit breakers while troubleshooting. They are usually located right there near the batteries. If that little red arm is out, it has been popped.
https://www.amazon.com/Zesugo-amplif...792417&sr=8-35

tropical36 · 08-06-2022, 09:40 AM

Quote:

Originally Posted by Tommy 1

Don't ask me how but I hooked my starting battery backwards. Now when I turn on the key nothing happens. Will not start and all dash stays blank. Even when I push the battery boost button I get absolutely nothing. What did I blow? This is a 2005 winnebago voyage with the gm 8.1. Thanks for any thoughts or advice.

Firstly, what does the Battery read and what is the polarity now?
If it's dead or near dead and the pos term in now neg, you still may be able to reverse the poles and for charging it back up correctly.
This used to happen quite frequently back in the old days with previous Ford owners trading for Chevy's.

tropical36 · 08-06-2022, 10:01 AM

Quote:

Originally Posted by Tommy 1

Don't ask me how but I hooked my starting battery backwards. Now when I turn on the key nothing happens. Will not start and all dash stays blank. Even when I push the battery boost button I get absolutely nothing. What did I blow? This is a 2005 winnebago voyage with the gm 8.1. Thanks for any thoughts or advice.

Firstly, what does the Battery read and what is the polarity now?
If it's dead or near dead and the pos term in now neg, you still may be able to reverse the poles and for charging it back up correctly.
This used to happen quite frequently back in the old days with previous Ford owners trading for Chevy's.

153stars · 08-06-2022, 01:46 PM

I think regular/automotive GM fuse boxes had reverse polarity diode . I can't remember if it blew out protecting or made the reverse sensitive circuits fuses blow instead. Sorry that's the best idea I have being unfamiliar with yours.

NMBluept · 08-06-2022, 04:12 PM

The Winnebago wiring diagrams show the chassis battery is provided by GM/Workhorse. Poke around a bit and see if you can locate the chassis fuse box (not the chassis electrical box with the 12v breakers). Either in or near the chassis fuse box I would expect to find a large fuse (maybe 300 amp) in the 12v line from the battery. First thing to do is as mentioned check the battery voltage with it disconnected, then find the fuse and check it with an ohm meter, if blown replace it and properly connect the battery. If you are living right that main fuse blew and protected everything down stream.

Good luck,

Gary RVRoamer · 08-07-2022, 02:56 PM

HERE is the Workhorse chassis tech manual for your coach. I don't know whether you have the P-series chassis or the W - both used the 8.1L engine.

Tommy 1 · 08-08-2022, 12:32 AM

After MANY hours of tracing and checking wires and fuses with a voltmeter I phoned a gm mechanic acquaintance and within 2 minutes he solved my problem. I blew the fusible link on the starter. It comes off the same post as heavy wire from battery. Replaced and problem solved. Thanks to all of you who responded with suggestions.