AMB affected by shared bec?
 

I was racing but my amb signal is low, my race director said the usual signal is 120-133 but mine is 70-88.

I am not sure what went wrong my amb is attached to a Y harness shared with a fan plug into the batt slot.

Could it be the 6v is shared between the fan & amb that's why the signal is low?

Most likely.

Could also be the signal is being reflected/blocked by the Al chassis or CF parts, depending where it is mounted.

It's mounted on the chassis was ok untill I used the Y harness. So I suspect it was the bec so I won't make the same mistake again.

It could also just be a transponder that is going bad. I had the same thing happen to me once. I pulled my hair out trying to figure out why it dropped a lap once in a while, then on day it started dropping almost all of the laps. It still registered sometimes but not most of the time. I sent it in to AMB and they replaced it with a new one for half price. Mine was like 4 years old so no warranty any more. Mine was mounted flat to the chassis too when it went bad on me. Being mounted flat to the chassis is very hard on the little transponder and it takes quite a hard beating that way IMO. I know there are transponder testers that you can set the transponder directly on and it tells you how strong the signal is. If you can find one of those it could tell you if the transponder is bad, or just something in the wiring /positioning that is causing a weak signal.

Good luck with getting to the bottom of this, its a frustrating thing to diagnose.:neutral:

I will connect direct to rx & test again. Hope it won't be the amb. It's just 1 year old:(

The transponders are usually so good that you can mount them in the worst places and they still work :D The transponder should have no alu or cf between it and the loop line.

First chek out it it is already ok. But if it is not then change the mounting position.