P1000 Electrical problem

[BrotherNov]

I've got a 2020 1000 purchased new in April 2020. Barely used, only 300 or so miles, very few of them requiring anything except turf mode. Kept in a heated garage and always on a battery tender. With the help of you guys I installed a dual battery/true isolator almost as soon as I got it.

Until this morning everything has worked flawlessly. Normally, I turn the key, both the main and aux battery's show 12.7 volts on the meter and it fires right up. Now when I turn the key both batteries show 12.7 volts but when I attempt to start it there's not enough juice to turn it over and the auxiliary battery immediately drops to 6 or 7 volts.

I was under the impression that starting shouldn't affect the auxiliary battery at all. Could it be that I have the wires backwards on my battery meter and the stock battery has shot craps on me? Or could it be an isolator problem?

Any and all thoughts are welcome, thanks in advance.

 

[Admin]

 

[BrotherNov]

I guess the mental exercise of explaining my problem cleared my head a bit. I put a volt meter on both batteries and they each tested just over 13 volts. Disconnected the tender, tried to start it, and the main battery tested at 11 volts.

Is that a pretty sure sign my main/stock battery has failed?

If so I'm kind of relieved as that's an easy fix. Gotta change the wires on my dual volt meter too

 

[P1K5Dave]

Seems premature for the stock battery to be tired. I'd have to do a full review of my dual battery wiring if I were you.

A quick test would be to wire your primary battery back to stock (two main battery leads only connected to it) and see if you're still having an issue.

 

[bumperm]

Guess I don't have it clear . . . when you measured the 11 volts, was that during engine cranking? If so, that is a reasonable voltage as the battery is loaded down by the starter motor. If it's not cranking, are you hearing the starter solenoid click when you turn the key to start? Another test to do is measure your main battery voltage and then turn on the head lights. Does the voltage drop down below 12 volts? As P1KDave says, check the wiring also.

 

[Remington]

I guess the mental exercise of explaining my problem cleared my head a bit. I put a volt meter on both batteries and they each tested just over 13 volts. Disconnected the tender, tried to start it, and the main battery tested at 11 volts.

Is that a pretty sure sign my main/stock battery has failed?

If so I'm kind of relieved as that's an easy fix. Gotta change the wires on my dual volt meter too

Sounds as if u either have a draw of some type when u try to start it or you have a dead cell in the main battery. Put a load tester on the main Batt and when the load switch on the tester is energized the needle will indicate if it can handle the load. you can read a full 12 or more volts standing and ur volt meeter cant pick up the load drop.

 

[BrotherNov]

Guess I don't have it clear . . . when you measured the 11 volts, was that during engine cranking? If so, that is a reasonable voltage as the battery is loaded down by the starter motor. If it's not cranking, are you hearing the starter solenoid click when you turn the key to start? Another test to do is measure your main battery voltage and then turn on the head lights. Does the voltage drop down below 12 volts? As P1KDave says, check the wiring also.

It measured 11 volts after attempting to start the engine. No clicking. And yes, I just checked and the main battery voltage drops below 12 almost immediately when turning on the lights. Thanks, it sure looks like the factory battery is bad

 

[CID]

It measured 11 volts after attempting to start the engine. No clicking. And yes, I just checked and the main battery voltage drops below 12 almost immediately when turning on the lights. Thanks, it sure looks like the factory battery is bad

Just about any auto parts store will gladly load check it for you.

 

[BrotherNov]

Thanks guys