mx5cartalk.com

OK, have put an aftermarket demister on our NA hardtop which is on a 2002 NB8B. I'm having trouble working out the wiring. I've done a search on the is forum and Miata.Net for an answer, and I can't seem to find one.

Now I'm aware of the cutoff switch which disables the demister when the softtop is down - I presume this is on the car side of the connector? I think this is where my problem is. I couldn't get hold of an NB demister plug and loom (softtop side) so I have replaced the plug with a different 3 pin one from Jaycar. I've had a look at my softtop wiring, and the black / white stripe wire doesn't appear to go anywhere - it perhaps just ends inside the loom cover somewhere? Certainly there's only the black and black / red wire which actually connects to the demister that I can see.

So, where does the black/white wire go to on the demister side? If nowhere, then presumably my problem is that the softtop down cutoff switch is stopping the demister working, so how do I bypass / fix this? BTW I checked the demister light came on with the softtop up, so the circuit is working

Presume someone else has had this problem???

Any help appreciated

Two Heads

NB8A hardtop on an NA8 here - made some notes about those wires as my two plugs also mismatched - will try to find notes, but in the meantime lots of info here:
http://www.miata.net/garage/hardtop/
& this is Hammer's hardtop with demister install on his NA8 with lots of detail & pics:
viewtopic.php?f=57&t=34566&start=15

Found notes:

1993 NA8 <-> NB8A Hardtop
purple 12v <-> black & silver
black 0v <-> white
red & white 0v <-> black & silver

Note: One of the aforementioned black & silver wires becomes a black & red wire just before attaching to the HT glass demister circuit.

Above is how mine is currently wired after checking voltages, but as I never use the demister I've not tested it to confirm it works. However, I noted the following, possibly in Miata.net/garage/ hardtop post:

NA8 <-> HT
purple <-> black & white
black <-> black & blue
red & white <-> white

Hence, the note to self to check mine one day & adjust wiring if necessary.