Review on 🔍 Certified AC Pro Car Air Conditioner Stop Leak Detector Kit: Glasses, UV Pen for O Ring and Hose Leak Detection - Professional Grade (438) by Daniel Roe

I took out the kit and put the batteries in. Unscrew the light cap. There is a small spring at the bottom and a large spring at the light end. So I put the batteries in with the positive pole down. That's wrong, the minus goes down, and the plus goes to the bright end. Batteries should also be in good condition. I also found that the body is aluminum or some alloy and the threaded connections provide connections that aren't very good connections. Even on the case I had to press the voltmeter probes very hard against the metal to make contact. When I first received the light I couldn't get it to work so I sent the seller email after email. He sent, so I have two headlights. About a year later I tried using these lights but neither worked and I put new batteries in both and neither of them worked. I couldn't remember which way the batteries were supposed to go. So I took my voltmeter and measured the resistance at the end of the switch. I had to push the probes very hard and make sure both switches were in the "on" position. I then tried the batteries both ways and voila, both lights worked. After playing around for 20 minutes I thought both headlights were bad. The screw connections are not very good, there are two on each light and you have to play with them, but once the light comes on everything works fine. Marked with felt pen + to the light end and - to the switch.