Dead battery? Alternator?

Hi all!
First post.

I recently installed a Midland 275 radio. I clipped the cigarette lighter attachment and wired it straight to the battery. Not too long after that I noticed my truck wouldn’t start up the same way and it would take more effort to crank it.maybe a week or so after the install.

i took it to the dealership for tire rotation and an oil change and they swapped out the battery for me when I brought it up, since it was under warranty.

Was heading out on a camping trip this weekend and the truck wouldn’t start. Jumped it with my wife’s car and it started and I went off and drove about 3 hours to our destination. Upon arriving to the camp site I parked the truck and turned it off. Got out and realized I wanted to move it up a bit further. Tried to start the truck, and it was dead. Couldn’t roll down the windows or lock the truck or anything.

I have a few questions.

1. The radio has an on/off switch on the handheld. If it’s off and wired straight to the battery would it still have a draw?

2. Would the 24f battery that was the replacement, be an issue as opposed to the 27f that I originally had. I didn’t notice it was a different battery until now.

3. If the truck started and I drove for 3 hours, is it possible at all that I have a bad alternator or would that be ruled out?

4. Normally when I have the truck idling I’m usually at around 14.4 and when the truck is off I’m around 12.7 volts. Now when the truck is idling it ranges anywhere from 12-14 and when it’s off it ranges from 9-12. Is this the sign of a bad battery or bad alternator or both?

5. Could the fact that the dealership gave me a 24f battery instead of a 27f have caused the alternator to go bad?

Thanks in advance.

 

Here’s my rig.

 

Big question, why the dealer. They are not your friend, you're just a wheel in their cog. They have no control of what happens in the engine bays.

 

I'm guessing because it's under warranty and he got a free replacement.

 

Sounds like all the trouble started with the radio install. Retrace your steps there. Make sure no fuses were blown during the clipping of the wires. Believe there’s a fuse/relay under the hood that affects battery charging / voltage. Maybe someone else will chime in with the specifics.

 

I don’t think the battery being a group 24 is the issue. The difference is mostly physical size, CCA and AH. They just used a cheaper battery to not have to spend as much on your warranty claim. I also don’t think it would damage your alternator. I have a dual battery kit that uses group 25 batteries and haven’t had any issues.

The issue is your idle charging. If it’s 12-14, that a big issue. Your battery isn’t getting charged. Need to get the alternator tested.

 

OP, like he said. Search this site for “alt-s” fuse. There are some threads about it causing charging issues. You can check it in the fuse box under your hood. The location is marked on the lid of the fuse box.

 

You need a digital multimeter. Start the truck at idle and measure the voltage across the battery post. This is the fastest way to see how well your alternator is working.

What is the radio? Brand? Model? Need to see how much of a load it is drawing. It might be sucking you dry as soon as the truck is truned off. Could be smart to wire it into a power source that comes on with the key instead of having it connected to the battery 24/7

 

I have since rewired it into a switch panel I have. So I have to manually turn it on from there and it is hooked up to ACC power. It’s a midland 275.

 

I use relays to turn my ham radio on after I start the truck, this last time I got a time delay on relay from

$15 Time Delay Relay 10 Seconds 5 pin 12V 30A 5 pin SPDT

https://www.amazon.com/gp/product/B0744HSF8P?ie=UTF8 which allows the truck to start up and not send voltage spikes to the radio. The relay is energized by a lead I ran to the 12VDC power port (switched). The switched lead is protected by a 3 amp fuse and the lead to the battery has a 20 amp fuse.

 

This is going to sound stupid but check the terminal connectors for corrosion. Your alternator is working ok if you’re seeing more 12V when the engine is on (and it seems ridiculous that a 2018 Toyota has an alternator issue). I’ve experienced a similar problem on my 80 series LC… stalled at a stop and wouldn’t crank, wiggling the terminal connector on the post removed enough corrosion to get good connection and crank the engine.

 

Update: sometimes it’s best to start with the basics. The culprit was a loose connection to the battery terminal. Tightened her up and it’s all good. Dealership swapped the battery back to a 27f as well. I did swap out the post to the terminal with some zinc posts I found at autozone wishing also give me 2 additional spots to hook up accessory wires instead of 1 from the OEM posts.
Rewired the radio to my auxbeam 8 gang switch and now turn it off and on from there.
Has been solid since.

Needless to say, sometimes it’s the basics. Shouldn’t ever overlook and jump to conclusions I guess. Glad it wasn’t the alternator.

 

Not stupid at all.
Check my last post.