Truck has been dead last 3 times I have tried to start it

[Jesse J]

So I have tried to start my truck the last couple times since I have gotten it running and the battery has been dead dead. like I left my lights on for 5 hours dead. But I have put te battery on the charger and it has fired right up like a dream. I did recently install an h3 upgraded harness which might be the issue? anywhere I should start?

[JustEmptyEveryPocket]

Start by watching THIS video all the way through. Twice. Then look up some more video explanations. Search for things like "parasitic draw" and "finding amperage draw". Then dive in with your multimeter and start having fun.

 

*Warning* Do not touch any exposed wire while grounded to the trucks system. This includes sparkplugs. (<Sorry I had to say it.)

[jdog]

Something is draining the battery,  usual culprits are radio if aftermarket,  glove box light, dome lights. Only other thing I have to ask is the battery good.

[75sv1]

I'd also suspect the alternator. As above, put a volt meter between the negative cable and the batter. Start taking fuses out. 

[Jesse J]

7 hours ago, jdog said:

Something is draining the battery,  usual culprits are radio if aftermarket,  glove box light, dome lights. Only other thing I have to ask is the battery good.

would not be suprised if radio is the culprit my dad says He has seen it on inside the truck a couple times.

[jdog]

There you go, pull the radio out and check how it's wired or install another one

[MiNi Beast]

Constant power wire for memory is backwards. I did that before. Good if you turn it off personally everytime, but easier when it shuts off with the key. 

[CGCWO]

Just a thought: if you’ve swapped your gauge cluster that also has the possibility of causing a draw. See this thread: