TyreWiz not working after battery change

My mountain bike had been sitting for some time and when I rode it last week, I found that both SRAM Quarq TireWiz tire pressure sensors were not working, the LEDs would not blink, and no pairing with the Garmin Fenix occured. New batteries needed, I concluded. After all, the original set of batteries had been in use for over 2 years.

A set of CR1632 batteries arrived in the mail today and I went about replacing them. Between my waning eyesight, the dimly lit basement floor, and my aching bones not appreciating that I had to get up 4 or 5 times for a tool, this took longer than it should have, but I did get both batteries replaced. Unfortunately, only the rear wheel sensor worked and had a blinking light. The front wheel sensor remained dark. I left it at that at first and went to my computer to find out where I had purchased them and if there was any warranty. I found the dealer website because I had emailed them with a question about the Zipp wheels that I had ordered together with the TyreWiz, but I did not find any order info.

So I went to the Quarq website and stumbled over the FAQ page. This briefly led to more frustration, because I was unable to view any images or download the manual (if you experience the same – it is at the bottom of this post). I perked up when I found the Device Will Not Wake Up chapter on the Troubleshooting page, though. I read the article with interest. Again, no illustration was available, but I gathered from the text that there might be an issue with the + pole of the battery not properly connecting with the device when the cover is on.

I went back and removed it again, made various attempts to bend the metal contact as suggested on the support page, but it did not work. So I inspected the inside a bit closer to find out how the two pieces – the metal contact on the cover and its counter piece in the device – should connect.

It turned out, they did not connect because they were at entirely different locations of the battery cover. The metal bracket that holds the battery in place and leads the + pole outward must somehow have turned a quarter turn inside the cover. I removed the battery, removed the metal insert, turned it back to where I thought it should be, re-inserted the battery, put the lid back, and got a blinking light! Both sensors paired and I can once again see the actual tire pressure on my watch.

Conclusion: The large contact that the support article mentions must be directly opposite from the dot on the cover, i.e. at 6:00 (see the illustration on page 14 of the manual – I do have Moto wheels). The metal bracket inside the lid is not glued in or otherwise held in place, and when it rotates, the contacts will become misaligned and not close.