Help - Tundra only starts off a jump

2000 Tundra was intermittently starting. My son was driving it and it wouldn't start at all. He got a jump and drove home. We replaced the battery with a NAPA AGM battery with 850 CCAs. No start. Replaced the relay. No start. Jumping the relay terminals with a wire and I get a click from the starter but no spin. BUT, it still starts just fine on a jump. So in my mind, it can't be the starter and I'd be pretty shocked if I got a bad brand new battery from NAPA. Cables are original (350k miles) and the starter is a NAPA rebuilt (I know, I know) with maybe 50k miles, and it works fine on a jump. Any ideas?

 

Could be the positive lead from the battery to the starter is corroded and it needs the extra amperage of being jumped to get enough amps to the starter. Start checking voltage on stuff with a multi meter and checking the wiring from the battery to the starter relay and to the starter.

 

Thanks man. I’ll give that a try. Can’t imagine what else it would be.

 

Internally corroded battery cables are pretty common.

I would START with taking off the terminals and really checking how the wires attach, and work your way down the wire from there.

How exactly are you jumping it? Good vehicle ground to bad vehicle ground or to the terminals?

 

Grounds, cables need to be checked. Make sure battery has a full charge (new ones usually don’t).

 

Terminal to terminal.

 

I did charge the battery after we installed it and it wouldn’t start the first time. Still no start.

 

If it starts fine with a battery connection to the outside of the battery cables but not when a battery is only connected to the inside of the cables, then it stands to reason the inside connection is poor. Clean battery cable connections and battery posts.

 

Stupid question, but you're using an AGM battery. Two questions:

• Have you tried starting the truck with a NON-AGM battery? Even if just for shits and giggles. The fact it's starting with a 2nd battery would suggest maybe your cables are fine, but points to the battery. EVEN if the battery tests out fine. Why would applying a 2nd battery via jump make it magically start, and give it the power it needs? Think about it for a sec. Unless the problem is between the battery itself, and wherever you're attaching the jumper cables (that would include bad terminals, or loose terminals, I got a nasty a click-no-start from having my positive terminal barely loose)
• Did you install the necessary part in the engine bay fuse/relay box to use AGM batteries? And in case you weren't aware of what you need to do with AGM batteries see link, and link. Not everyone has found it necessary, but it bears repeating, especially if you want that AGM battery to last.

Try jiggling/tugging/twisting the battery leads (w/o a jumper intact) while someone tries starting. Does the truck start?

 

I reasoned the same, but we cleaned the terminal ends with wire brush and scotchbrite pad until shiny and snugged them up good to the new battery. There was significant corrosion/acid salt buildup on the terminals and old battery before that tho.

 

These trucks are absolutely notorious for getting corrosion inside the cables, rotting them from the inside out.

But again, if the corrosion is inside the cables, why would adding another battery fix that problem? It sounds like you have a bad battery, and while it may show proper voltage, it sounds like the battery doesn't have the CA or CCA (cranking amps) to push over the starter.

Who tested the battery, and using what method? They weren't a fucking idiot, who only tested the voltage, right?

 

Only have tried jumping with non-AGM batteries but not by installing in the terminal clamps. Stupid answer but I’m going to read those links now because I had no idea anything else was required for an AGM battery.

 

Do this.

Pull the terminals off your battery. Jumper a non-AGM battery to the terminals, completely removing the truck from the AGM battery. Turn over the truck.

If it starts, the AGM battery is the problem, and whoever tested it may be an idiot, or we're missing some other key piece of info.

 

I am a fucking idiot. I’ll just get that out of the way. I didn’t test the battery at all. I dropped it in. Didn’t start so I threw my trickle charger on there on the 2 amp, AGM setting until it said 100% …

 

Sorry, I'm being unnecessarily harsh this AM. Coffee hasn't kicked in yet. But yeah. DOA batteries happen. we see it at least once a month or so on here. Have it properly tested.

 

I’m going to do this and we have a couple good (worked when removed) non-AGM batteries laying around - my son can’t stop tinkering with his diesel. Anyway I’ll try a few things to isolate the battery from the problem and look at cables/connections this morning and report back. Thanks

 

No offense taken. Stupid is as stupid does

 

The stupid jumps into all of us sometimes. For all I know, I may end up being the stupid one at the end of all this

If you have spare batteries, that's a good shot also. On threads like these, we usually tell people to pull the battery and run to the local auto parts box store to test, if you don't have a quality tester on hand. Our last person who found a DOA battery, brand new, was back in early August IIRC.

 

Terminal contact to battery was my recent no start issue. Jumping the battery would bypass that connection and create a new connection to a new battery. Still reeks of terminals.

 

Ditto! In my case, I installed a new improved (+) battery terminal to support my amp. Random click-at-start happening until a couple months later, which is why I didn't put 2+2 together.

It may've been that stupid L-shaped OEM bracket that bolts onto the terminal that was what was more loose than the terminal itself. Posted about it over here when I finally figured it out.

 

Ok, so I feel extra stupid now. I cleaned the terminals gooder and it works! I took the positive ends off the t-post on the terminal, took apart the negative terminal, dropped everything in a bucket of baking soda water, scrubbed the crap out of the cable ends until they looked like new pennies, rinsed everything, greased it all with dielectric grease, put it all back together, and viola. She lives. So basically what I should have done to begin with when I installed the battery.

I went ahead and ordered the "big 7" cable kit from jeepcables because the cables look like shit and they're 25 years old. Also going to get or make an AVB as Shifty suggested so the AGM battery will charge properly.

Thanks everyone for the help!

 

Shitty terminals strike again! Glad it was a simple fix.