So I have this white 1990 Miata. It has a production date of 8/98 and the last four numbers of the VIN are 7000. It has spent it life so far out here in the dry west. No salty situations. It has 72000 miles on it. Decent interior, no tears or stains on the seats just dirty. The front bumper has a delaminated area that needs work and the fenders have some dents that have been mudded. There are some small dings and dents here and there but they are PDR types.
It feels like it needs a clutch when driving but gets up and goes quick with no shifting problems. Runs fine. I was told it has been taken care of by the previous owner for the past 4 years.
It needs a new top and I have a top for it. Pull top off one Miata and exchange to the other.
So my lifted Miata had a nice top that I had installed but now it does not. Before installing it on the 1990 Miata it need to be vacuumed and cleaned. Inside and out. Gravel/dirt roads can do that to a cloth top.
The new top has the defroster rear glass but the car has no plugs. I have the plug that goes in the car but found no wires to connect it to. The plug came with the parts car that came with it. But no switch either
I will look on ebay for the correct switch and plug for the soft top. The new top does not have the correct plug on it that will plug into this one. It has two separate plugs.
That's an NB top you're putting in? Nice upgrade.
When I ordered the soft top the other car had a heated window. I didn't know it didn't have the plug until I installed it on the car. The 1990 I knew it didn't have the plug.
After installing the soft top on the 1990 Miata. I had to replace one bolt, the push in retainers that hold the carpet in place and swap over the latches from the original frame. They were factory painted ones that belonged to the car. The little caps on the front of them needed replacing also. But I came up with two used ones that are in fine shape. During this install on the 1990 Miata, I needed to cut the spaces for the Hardtop latches. The original side covers in the car were not in the best shape. They (PO) had installed a dual hoop chrome roll bar. I removed that and sold it. So the covers were damaged. So the parts car that came with the 1990 Miata was black interiored. Those were in nice shape. Between the two sets I had the little square clips and seat belt guilds to make them compleat.
These are the clips from Napa that fit to hold the carpet in place. But you have to trim the length. The one in the upper right is a trimmed extra one left over.
This is the "new" covers installed. And new latches from Mazda for the Hardtop. I am in debate about installing a cross bar since these have the factory openings for it. The one that was there went to the lifted Miata. I could not clean it and make it look nice enough for the 1990.
So once the soft top was installed on the 1990 Miata I installed the old top on the lifted Miata. About two weeks or so the window fell in... 
this is a picture of me reinstalling the window. This made me glad that I did the swap. You can reinstall a window if it falls in. It has lasted urethane back in place for about 4 months now. With no window leaks.
Now that the clutch is done and test driven. The work on the fenders and there dents begins. The passenger side fender was the worse. So I started there.
If you zoom on the picture you can see how the original dent was repaired. Old school style of dent repairs. Drill holes. Screw in slide hammer. Pull out dent. Fill holes with Bondo. Prime and paint.
The front fender mount needed to be straighten a bit. And the over spray on the wheel liner gave away that there had been other incidents with this car. The lower fender mount by the door was just covered in dried dirt and no surface rust. I was surprised due to how much leaves and dirt was wedged in that area.
The passenger fender from the parts car had some dents but those were repairable. A little hammer and dolly work with some filler. Sanded down the whole fender with 320 then 600 and primed the filled areas with a white primer.
I did the same on the drivers side. This is the pictures of that instal.
The kids and I put a used NB top with defroster on our 1991 Miata. We found no wiring to work with, so we did our own using a factory switch, a timer relay, and an LED. It works great. The only thing that's a little strange is that the latching switch needs to be turned on and then off for the timer to be able to turn it off. The LED is to see when it's on. If you're interested, I could scrounge up the wiring diagram.
The left damaged fender was a factory replacement fender. You can see the Mazda decal on the inside of the fender. The "new" fender off the parts car was in a lot better shape than the bondo ozzing fender it replaced. The replacement fender needed be completely sanded down due to chips in the non factory paint on it. It also was a factory replacement fender. I had to reapply the Gravel guard on the sides. It did not have it from whom ever replaced it on the parts car. 
I used Gorilla Bedliner on both the left and the right fender. I bought some spray bombs from Napa for the primer and paint. I still needed to run over the paint with some 600 grit sand paper to "nib" the dust off.
And this is it installed.
pkingham (Forum Supporter) said:
The kids and I put a used NB top with defroster on our 1991 Miata. We found no wiring to work with, so we did our own using a factory switch, a timer relay, and an LED. It works great. The only thing that's a little strange is that the latching switch needs to be turned on and then off for the timer to be able to turn it off. The LED is to see when it's on. If you're interested, I could scrounge up the wiring diagram.
Did you have to run new wires to the dash?
You can see the difference in the fender to the rocker panel
I will need to scuff and paint the rocker.
This is what I purchased from Napa as far as spray bombs.
And sand paper from Amazon. It has from 600 - 80 grit discs. Works good. 
In reply to MyMiatas :
Yes. Tapped into the fuse box for power and ran all new wiring for everything. I remember researching it and some cars were supposed to have factory wiring such that just a switch would need to be added, but there was no sign of that wiring in our car.
So during my drives after installing the clutch the car had this vibrating noise. I thought it was something rubbing on the hood. 
I decided that I needed to remove the SuperCharger. It moved more than it should when handled. As long as I'm in there I might as well install extras that you should have there to block the heat
After removing I found this. It is a mounting bracket that is hidden under the Supercharger.
It is not a five minute job removing one. The air filter is small and stuffed in a tight area.
To install the heat wrap you need to remove the header. After removing it I cleaned up the header with rust Remover and denatured alcohol. Then spray bombed it with high temp silver paint. 
Wrapping a header took a couple trys to determine how to use the amount bought. I ended up cutting it in half and wrapping them individually.
I used stainless steel zipties to fasten it. The heat shield also received a heat barrier adhered to it. 
By the way. Do not wear shirts that you want to wear again while wrapping headers and applying fiberglass heat shield. I had to through out one of my Classic Motorsports t-shirt after is was done. :0( It did not even cross my mind to wear a dirty shirt. 
pkingham (Forum Supporter) said:
In reply to MyMiatas :
Yes. Tapped into the fuse box for power and ran all new wiring for everything. I remember researching it and some cars were supposed to have factory wiring such that just a switch would need to be added, but there was no sign of that wiring in our car.
When installing the better covers. I peeled up the carpet to see if there was a hidden plug, but there was not. I really should install it since it is there on both the hard top and the soft top.
Pkingham what did you use for a timer relay? And where did you pick up the switch for the defroster?
MyMiatas said:
Pkingham what did you use for a timer relay? And where did you pick up the switch for the defroster?
I'll see if I can find where I sourced the relay and switch. In the meantime, here's the final wiring diagram and pics of the switch and indicator light. The switch is a combined defroster and fog light switch if I remember correctly the car had the fog light wiring, but we haven't added lights yet.
NAPA Stoneguard is a perfect match for the texture on the sills, fyi.
A little more info on the defroster wiring.
The switch is an OEM part which combines fog/driving lights with defroster. I got it from rev9autosport.com. 
The timer relay came from ebay.
I ended up buying a couple relays with the mating harnesses just to get the connector/harness:
The led came from Amazon:
The label for the light came from ebay:
I had to wait until the car was home to remember a couple more details. To tap into the fuse panel, I used:
The big one works ok, though I don't remember what circuit I used:
And here's a pic of where the relay ended up in the trunk by the left side hinge:
Hope that helps.
Thank you again for the info on installing those items.
Keith Tanner said:
NAPA Stoneguard is a perfect match for the texture on the sills, fyi.
If we have another warm weekend like this one. It could happen next weekend.
In the last picture I posted of the heat shield. I installed the fiberglass insulation on both sides of the shield. Now with the wrap on the header and on the shield I am thinking that should reduce the heat on the Supercharger.
I repaired the broken bracket that holds the Supercharger in place. And painted it with some of that high temp paint from the header. And reinstalled it.
You can just make out the heat sheild with the fiberglass insulation on it on this photo.
Enjoy the blue smoke the first time that header wrap comes up to temp. It can be dramatic :)
