Electrical is gone...

[djkid97]

Hi all.. I'm a newbie, so I'm hope this is appropriate. I searched for a specific thread on this topic but didn't see one. I've not tried the general troubleshooting tip about inspecting the two big "bundles" of wires, but I will.

In the meantime, in case anyone has suggestions: i've got a 97 Limited 4x4. Suddenly I get zero electrical -- eg no dome lights when opening door; nothing is getting power. Prior to this problem emerging, the only electrical issues I had were that the washer pump didn't work and one headlight was out. I started working on replacing the headlamp assemblies while waiting for upper and lower control arms I'm replacing. I mention these things in case maybe I shorted something somehow.

I disconnected the negative from the battery while working on it. For a while, I could reliably re-attached the negative cable and everything would be fine. Then I noticed it would not have power when reconnecting the battery (like I"m seeing now) but then I'd fiddle with the connection and it would work again. Now electical is just dead. The battery is fully charged (I charged it). The headlights have been removed. When my buddy tested continuity through the connectors to the water pump, he sensed a short.

Is it possible that i've shorted and blown some sort of master fuse? Is there such a thing? Any other clues on how to start diagnosing?

thanks!

 

[Mbrooks420]

Connections to the water pump?

My first guess is that you have a bad connection to the battery, or have a bad cable. Do you have the factory wrap around steel clamps, or lead block style?

 

[djkid97]

Thanks for the quick reply. Image of terminal is attached. FWIW, it's sparking when I connect it, so I assume it's connecting

 

[974X4BLACKSPORT]

That is the stock original negative battery connection, it does not look that bad of shape, but it does need cleaning. Have you cleaned the round part on the battery and the inside of the round metal terminal on the cable? Very important to keep that part as clean as can be!

 

[Mbrooks420]

Wiggle all the cables around really well and try it again.

Also agree with above I would polish the insides of both terminals until they were clean and shiny.

 

[djkid97]

will do and will then report back...thanks. BTW, is there some sort of "master" fuse that I can check? I'm thinking maybe I blew it...

 

[donalds]

Check the wire
Bend it look for hard spots
May be corrosion in the wire itself
Under the insulation

This adds very high resistance in the wire

 

[djkid97]

Thank you. I cleaned the terminals but nothing changed :-(

I then checked the Power Distribution Box under the hood with a grounded continuity checker and all of the visible fuses are getting power. There's an odd pattern of fuses not getting power in the inside-of-cabin fuse box. Looking at it from the side, it tests out like this:

Good Bad Good Bad
Good Bad Bad Bad
Good Bad Bad Bad
Good Bad Bad Bad
Good Bad Bad Bad
Good Bad Good Bad
Good Bad Good Bad
Good
Good Bad
Good Bad

The "Bad" fuses have not burned out.

I'm guessing from this that something upstream from the inside-of-cabin fuse box is not working or is shorted. Any ideas?

Thanks
Danny

 

[Turdle]

Yes there is a master ( 175 amp I think) fusible link right off the power distribution box ( fuse box under hood). It is a bolt in item,

Kinda looks like this

 

[Turdle]

Thank you. I cleaned the terminals but nothing changed :-(

I then checked the Power Distribution Box under the hood with a grounded continuity checker and all of the visible fuses are getting power. There's an odd pattern of fuses not getting power in the inside-of-cabin fuse box. Looking at it from the side, it tests out like this:

Good Bad Good Bad
Good Bad Bad Bad
Good Bad Bad Bad
Good Bad Bad Bad
Good Bad Bad Bad
Good Bad Good Bad
Good Bad Good Bad
Good
Good Bad
Good Bad

The "Bad" fuses have not burned out.

I'm guessing from this that something upstream from the inside-of-cabin fuse box is not working or is shorted. Any ideas?

Thanks
Danny

Is this test with both key on and key off?

Have you checked all fuses?

Another thing to check is the battery saver relay.

 

[djkid97]

Thank you. Okay, here's a complete mystery. I just turned the key on and everything seems fine. It was not that way last night. I'm not sure what I could have done that fixed it...

What is the battery saver relay? Could I have triggered that and then it timed out and recovered on its own?

 

[donalds]

If it ...fixed itself over night ...
Then look for a bad wire connection
Most likely a bad or dirty battery terminal
Or fusible link connection


First place I would start is ground straps
Body
Engine starter
Back of engine
Ect.....

 

[djkid97]

Will do. Now the fun part will be figuring out how ;^) . Thanks again to you and Jon. I'll google the battery saver relay

 

[massacre]

Sounds like you have a bad connection. Any time power is fine one minute and then completely dead the next, that’s what I suspect
Ymmv