Often (but not always) when I start up and drive off to work in cold(ish) conditions with the roof up, after about 1/4 to 1/2 a mile, the PRHT warning beeper starts warbling away. No warning lights etc showing, just the beeper. After a mile or two (or sometimes 3 or 4) the beeper stops, then sometimes starts again, then (eventually) shuts up altogether with maybe 5 miles covered. It is then generally fine for the rest of the journey. It’s almost as if something is “warming up” and then working normally. The roof appears to operate normally (although to be fair I’ve not tried operating the roof while the alarm is actually sounding). I’ve tried releasing/refastening the roof release lever on the move, just in case it wasn’t fully “home” but it made no difference.
The car does have a PowerTop module fitted, and it appears to be working normally.
Anyone seen similar? Ideas where to start looking?
First thing I would do is disable the smarttop and run the car for a few days to see if the problem goes away. Also check if the smarttop has the latest updates applied.
I would start by disconnecting the smarttop module and re-instating the original wiring. If you didn’t fit the module originally then fitting instruction can be found on the web or possibly on MX5 Parts web site.
The Smarttop modules rarely go faulty but sometimes they need a reboot.
If this does not cure the problem then I would spray switch cleaner onto the micro switches that are hidden away but accessible when you know where they are.
If you want a chat about their locations PM me with a mobile number and I’ll point you in their direction.
The previous replies are the most likely remedy but I have to ask - are you sure it’s the roof beeper and not just something on the passenger seat? Took me a while to discover why mine beeped when I went to work after I first got it, turned out to be my laptop on the seat, fastening the seat belt or putting it on the floor cured it!
They were very good with us when we had a similar problem. Laptop and internet link up to look at our module. midnight there and 07:00 a.m. here.
I had to send it back to be repaired under warranty - but it was sorted.
Hmm - It would appear the problem lies with my SmartTop module. The alarm only warbles when the ST module is “on” (switching ST off while it is sounding silences it, switch ST back on and the warbling starts again) and there are no other warning lamps etc which would be expected on a “standard” car if there was a problem with the “roof unlatched” switch. For the time being I have simply disabled the “roof unlatched” alarm setting on the ST module, with a view to looking a bit closer once the warmer weather returns.
