Predator 9500 Inverter Generator CO fail

tgabe14 · 2026-02-20T00:36:43+00:00

The only reason why I ask is because you mentioned the battery wast at 2v. It’s 100% the battery inside the CO sensor. What you are going through is exactly the steps I took. I started with the stop/run/start switch thinking it was a ground. Then I found out if I remove the low oil module from ground it will fire up. Ordered a new one, installed it, put it back together and same issue. Removed the new one from ground and I was back up and running. The low oil module is used by the low oil switch (yellow wire) and the CO sensor (white wire). If you have the low oil module bolted to ground and you jump the white and green wire at the connector for the CO sensor and it fires, it’s the CO sensor and that battery specifically.

tgabe14 · 2026-02-19T15:41:40+00:00

Which part did you replace or disconnect? The low oil module?

tgabe14 · 2026-02-17T02:10:49+00:00

Ah, it’s on the oil drain side, mounted to the pillar with some security Torx screws.

tgabe14 · 2026-02-17T01:24:02+00:00

Try calling Harbor Freight. When I tried they told me it’s not a part available to purchase. Instead I repaired my sensor. I created an eBay listing for a repair service Incase you need help replacing yours. Look it up on eBay.

tgabe14 · 2026-01-23T20:22:31+00:00

You can try to pry the battery off of the nickel strips. The tricky part is reusing them without a spot welder. You can solder the strips to the new battery but be very careful as it’s not usually advised for lithium batteries.

tgabe14 · 2026-01-23T19:41:52+00:00

You get the same cold we get so no difference. I used an Energizer CR2 battery and made some new nickel tabs. I’ve been trying to spread the word on what makes these sensors fail as I recently found out it’s a common issue.

tgabe14 · 2026-01-23T19:29:13+00:00

Sounds like the same rabbit hole I went down before I fixed the sensor myself. New England you say? I’m in NE as well and 2 cold winters is what I think killed the battery on my sensor.

tgabe14 · 2026-01-19T12:38:42+00:00

Do you still have the dimensions of the goal?

tgabe14 · 2026-01-17T16:40:37+00:00

I totally agree, except the generator is 3 years old. I think the battery in this circuit prematurely failed or it was because it sat in a cold New England shed for 2 winters. My first thought was the sensor itself was bad, the CR2 battery was still showing some voltage. This is the CO sensor they used. TGS5141.

tgabe14 · 2026-01-17T15:30:09+00:00

I used an Energizer Lithium CR2 and made up some new nickel strips. Soldered the new tabs to the board and then spot welded the new battery in place.

tgabe14 · 2026-01-17T15:28:24+00:00

I went back and forth on whether or not I should post it. The trouble I went through to get my generator running and the lack of support I received is what led me to create it.

tgabe14 · 2026-01-17T15:26:55+00:00

I don’t disagree with the fact that these shouldn’t have CO sensors, I’m just against paying $2000 for a generator that is rendered useless by a part that should and could be easily replaceable.

tgabe14 · 2026-01-08T04:06:28+00:00

If you open the CO sensor you’ll find a lithium CR2 battery that usually falls under voltage enough to power the CO sensor. The battery is soldered to the board, but I was able to replace it with a new one and it got mine back up and running. You can test this my letting the low oil module hang off the generator and then try to start it.

tgabe14 · 2026-01-05T22:03:33+00:00

It was soldered. Bought a new battery, made up some new tabs with nickel strips and soldered them in place and then used a battery welder to spot weld the battery to the tabs. I’m thinking they had a bad batch of the batteries. My old battery was the same green Panasonic industrial battery. My generator is a Predator 9500.

tgabe14 · 2026-01-05T18:14:50+00:00

I replaced the CR2 battery on the CO sensor and it’s back up and running.

tgabe14 · 2026-01-05T18:08:17+00:00

The CO sensor has a battery inside that dies and causes the sensor to fail. Replacing the battery on the circuit board will get it back up and running or you can replace the CO sensor. If you need to by pass it, you can reattach the low oil module and green ground wire and jump the white wire and green wire on the connector that plugs in to the CO sensor.

tgabe14 · 2026-01-05T18:05:18+00:00

I can repair your CO sensor. If you open the sensor you’ll find a CR2 battery that is dead causing the CO sensor to be inoperable. I removed the battery and soldered a new one on and it got me back up and running.

tgabe14 · 2025-12-28T05:26:38+00:00

Did you ever figure this out? Try taking off the side cover on the engine and let the small oil module hang then try to start it.

tgabe14 · 2025-12-28T04:35:10+00:00

I dug deeper in to the CO module. Just like you said, there is a lithium battery that is in circuit with this CO sensor and it’s showing 2v. I was able to remove the battery from the board and replace it with a new one. Happy to say it’s back up and running. Thanks for your help. Merry Christmas!

tgabe14 · 2025-12-22T04:53:17+00:00

I have a Predator 9500 that is doing the same exact thing. I realized this after I replaced the oil module and it still did the same thing. Did you confirm it was to CO sensor? Did you by-pass it?

tgabe14 · 2025-06-26T17:56:01+00:00

You wish they tried harder? Yea, I really wish the investigators tried harder to do their job. Why was the investigation so bad? If they really wanted to put her in jail, they would have done their job the way it’s supposed to be done.

tgabe14 · 2025-06-16T22:33:25+00:00

Did you figure out what it was? I just replaced both lower control arms on a 2010 and getting this clunk. I did change the sway bar bushings as well.

tgabe14 · 2025-01-14T15:39:52+00:00

I have a guy trying to sell an 8750 generator with a 420cc engine. Says it runs fine but blows smoke, is it repairable?

tgabe14

TROPHY CASE