No power coming from the under-hood fuse box

1998 DODGE RAM
114,000 MILES • V8 • 4WD • AUTOMATIC
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JUGGALO9909
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  • 2 POSTS
After listening to music with subs pounding for longer than usual, the next time I started my truck it wouldn't start or stay running unless I gave it a little gas. Then three tries, nothing at all. No lights. No clicking. No power to the inside fuse box. It's got power to the under-hood box. A few fuses only have 6.5volts. But most are at 12v like they should be. Power to the starter is good. No relays look burnt under the hood. One relay inside looks kind of rusty. But not burnt.
Nov 3, 2021 at 8:43 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
Hi,

What electrical does work? As far as the interior junction box, power is supplied to it via fuse 1 (50 amp) in the power distribution box under the hood. Check that fuse. In addition to checking the fuse, confirm there is power both to and from it.

Here is a link you may find helpful.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

I attached the wiring schematics for the entire power distribution system. It was three pages long, but I had to cut each one in half to make it readable for you. I did overlap them so you can follow from one to the next.

Let me know about the fuse I mentioned. Also, let me know where you get power for the amps. My primary concern at this point is the under-hood fuse box is bad. I'm not sure why you are only getting 6.5V to some of the fuses. They all should have 12v.

Let me know.

Joe

See pics below.
Nov 3, 2021 at 1:36 PM
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JUGGALO9909
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  • 2 POSTS
There is no power beyond the under-hood fuse box. Nothing turns on at all. No headlight, flashers or anything. My amp is connected straight to the + battery terminal. Also, my battery will show 6.5v unless I ground my test light to the negative battery terminal. Then it reads 12v. I charged my battery, and the charger didn't show it as a "bad battery", but it should have 12v no matter where I ground to, right?
Nov 4, 2021 at 7:03 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
Hi,

If you have a good ground, yes, it should be 12v. Keep in mind, the further away from the battery you get, the more resistance will be introduced, but that shouldn't drop it to 6.5v.

Have you checked the ground at the engine and body to make sure it isn't ready to break? Also, is fuse 1 showing 12v in the under-hood fuse box? That is the fuse that powers the IP fuse box number 1.

Joe
Nov 4, 2021 at 10:29 AM
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