2003 sequoia electrical problem

I had a fuel pump ground wire,mounted too the frame burn,and get up into the interior right floor harness causing damage. In trying too trouble shoot/repair, i discovered the frame is carrying a 10-12 volt charge. My meter shows a charge between body ground and frame ground,when the battery is hooked up. Ive followed the large main wiring coming off the battery looking for a visual contact or short circuit,no luck. If i leave the battery hooked up for 20-30 seconds it starts melting other wires contacting the frame.Any suggestions or insight on troubleshooting?

 

Man, that is a good one.

Are you in an area where they salt roads in winter? Or do you launch boats in salt water?

Just trying to gauge how much of a factor corrosion may be. Some people have had weird experiences when connectors get corrosion and start throwing charge through things.

The first thing I'd be doing is unplugging the alternator, in case it's fried/shorted internally. Then test again. If it's still throwing charge into the frame, only thing you can do is selectively unplug connections in strategic places on the body harness to find out what branch the faulty connector is in, and continue downstream to isolate.

 

Thanks for the quick response. No frame or body rust whatsoever. This truck spent its whole life in Montgomery Alabama. Ive been racking my brain for a couple days with this. Thx ahead for any more insight or suggestions on how too fix this.

 

I bought my truck not far from you in Auburn. Same situation. GA truck its whole life. I can't urge you enough to pop the (+) cable off the alternator. My gut is telling me something shorted inside, and it's grounding out. I think the ALT fuse is supposed to blow in that case, which is suspect if so, but ...

Is there anything aftermarket on the truck? Brake controllers, alarms, that kinda thing?

 

No aftermarket equipment, that I can tell of. It is a limited model,with factory tow package, power/heated seats etc. ..so lots of wires in the harness'. I just bought the truck from the original owner with this problem. Its got about 260,000 miles on it, and performed flawlessly for 20 years for him and family. Until this electrical issue happened when leaving a walmart parking lot. He didnt want too put any more time or$ on it,and put it up for sale. I will disconnect the alternator and check the fuse. It looks like original denso. I was looking for a project truck,and this was a one original owner,no rust sequoia. I got it dirt cheap.

 

I probably would've jumped on it too if dirt cheap. I love deals like that. It's probably something stupid: Either a pinched conductor somewhere, or more likely something electronic shorting to ground. I'm sure others can chime in with ideas, everyone on here is usually pretty helpful.

 

Thanks shifty, the main + alternator cable had a half asked splice in it, and had worn thru the layers of electrical tape. It was "hidden" on top of the front frame cross member. Didnt see it until I disconnected it. Thanks for your time too help me troubleshoot it. ✌

 

Whats wrong with people!!! Glad you found the problem

 

Hell yeah, and got a cheap ass southern truck to boot, from the original owner!

@Johnlkubas now you need to do the 'big three' upgrade! Gotta replace those cables anyway

Link to more details: https://www.tundras.com/threads/04-sequoia’s-150-amp-alternator-swap-on-a-00-tundra-the-3-big-upgrades.67222/

If nothing else, you can look into cables there. If you need help finding harness p/n to get back to factory, LMK.