Electrical issue, where to start?

[blinn]

I needed to make a quick run to HD last night, I had driven the truck earlier in the day. The engine turned over fine, sputtered and stalled which is normal on the first try. I turned the key back to start again and nothing happened, I also noticed the dome light had turned off. I had no electrical anything. I popped the hood and checked the battery connections, both were tight. When I forced the negative post clamp a bit the dome light in the truck lit so I jumped in to try starting it again. I could see the battery through the bottom of the hood that was still open. When I turned the ignition a small spark came from the negative battery post and the car went dark again. Each time I moved the negative clamp a bit the same thing happens, the cabin lights come on but when I turn the ignition a spark from the clamp and it goes dark.

I’ve tested the battery and it’s fine, what’s next?


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[hotrod45]

Clean the battery terminals.

 

[WilliamS]

Terminals first if you saw an actual spark. Coke-Cola and some baking soda it will literally fall off the terminal.

 

[Gr8bawana]

Terminals first if you saw an actual spark. Coke-Cola and some baking soda it will literally fall off the terminal.

Forget the coke and just use baking soda and water with a stiff brush unless you like making a sticky mess under your truck that attracts ant.

 

[blinn]

Curios, there are 3 wires running to the ground terminal. A heavy one that runs to the fuse box, a lighter gauge that runs into a bundle going under the block and a 14 or so gauge that runs to the driver fender. Does that sound right? I’m a classic Mustang guy and have never worked on this truck much before [emoji1]


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[hotrod45]

Curios, there are 3 wires running to the ground terminal. A heavy one that runs to the fuse box, a lighter gauge that runs into a bundle going under the block and a 14 or so gauge that runs to the driver fender. Does that sound right? I’m a classic Mustang guy and have never worked on this truck much before [emoji1]


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That sounds typical. If you're inclined to do your own work, next time you're near an auto supply, pick up a proper tool for battery terminals. It will have an internal brush that works when you rotate the tool while it's on the battery post; and it will have a tapered brush to fit into the end on the battery cable. Personally, I prefer to keep the battery dry. Always protect your eyes when using any kind of brush around a battery.

 

[OCDTech]

That sounds typical. If you're inclined to do your own work, next time you're near an auto supply, pick up a proper tool for battery terminals. It will have an internal brush that works when you rotate the tool while it's on the battery post; and it will have a tapered brush to fit into the end on the battery cable. Personally, I prefer to keep the battery dry. Always protect your eyes when using any kind of brush around a battery.

Ive got one of these tools literally everywhere, toolboxs, all three cars, prob some in couch cushions. Ha some tools i just "collect". Flashlights are another one.

 

[blinn]

Cleaned the terminals and actually removed the 3 ground wires. With the 2 heavier gauge wires connected the truck started. I’m not sure of the one that goes to the DS fender, when it’s connected I experience the same problem. Thanks for the advice everyone!


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[SYKRAMMAN]

Cleaned the terminals and actually removed the 3 ground wires. With the 2 heavier gauge wires connected the truck started. I’m not sure of the one that goes to the DS fender, when it’s connected I experience the same problem. Thanks for the advice everyone!


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I would clean or replace and reinstall that body ground imho soon. These trucks don’t play nice when they have grounding issues, trust me. Also do the same with all the othe 6 or 7. At least check them for corrosion (green/white ooz) rusting, etc.

 

[SYKRAMMAN]

I didn’t know they made a 4.7 in 99?