Adding Wiring for a heated rear window in a 1990 Miata

[jdm]

Gentlemen,

Thanks to a vandal I need to replace my top. Insurance will cover part of the cost. The top I had was the first replacement for the original top and had a glass window. If I want to have a heated rear glass in my new top how difficult is it to add to the wiring harness in a 1990 NA with the 'B' package? If it matters I am doing the top install and going to add new carpet from Mahura when I do the top. VIN jm1na3518L0124057

thanks,

John

[Demon I Am]

The factory wiring should have the outlet in place, IIRC. I know there is a thread around here showing someone making one out of scrap wire and spade connectors. If you owned an NB, I could have that in the mail to you, lol.

[jdm]

Thanks Demon,

I did find this on another site. It is for adding a circuit for a hardtop but the part numbers and process should be the same.

Custom Defroster
If you want to use the defroster element on this top, you need to build a custom setup with a switch, relay, fuse, and NA- or NB-style connector on the rear deck.

Dash Switch

Part Number NA75-66-460, MSRP $55.20
There are two types of dash switches, with and without integrated foglight switches. This part number is for the one without a built-in foglight switch. It installs in the blanks to the lower left of the steering column.
Defroster Relay

Part Number LA40-67-740, MSRP $24.20
This relay plugs into the harness behind the trim plate in the trunk in the license plate area.

Frankenstein Bolts
Part Number NA01-R1-38XB, MSRP $12.44, 2 needed
These replace the plain screws on the chrome plates just in front of the trunk lid and hold the hardtop down at the back.

Fuse Block

Part Number N008-66-730, MSRP $13.60
This plugs into the harness by the battery. If you have a power antenna, then the fuse block is already there and you just need a fuse.

[Rogue]

1990s were not factory wired for Defroster, that came in 1992.
You would have to fab the whole system.

[90blue]

You may be able to find a switch at a junk yard for one of the early (similar years) Mazdas

[Demon I Am]

Better yet, one of our reseller forum supporters, like ScratchNSniff might have just what you need!

[jdm]

Thanks, I will shoot him a request and see if I have any luck.

[ScratchNSniff]

I should have 1 Fog Panel Switch...

[jdm]

Great,

What do you want for it? You can PM me with details or can we do this through panjo?

Thanks again