How much heat from the heater is good?

You do not say whether you were on recirculation or not, what the fan and ac settings were, how long the engine had been running, and what speed you were driving (top down, I assume.)

Normally the foot vents in a Miata do put out blistering air. Not a figure of speech, blistering.

Leon

Having absolutely NO experience with the stated problem and also needing to agree with Leon wholeheartedly about the use of the term "blistering", and having read over the years complaints concerning heat vs no heat, I would tend to investigate the flapper/shunt thingie (technical term there) connected to the recirculate/fresh slider on the panel.

I think I remember reading somewhere that it tends to fail or not close properly, sending heat where it is not intended to go.

IMHO. And it's a highly uninformed opinion so YMMV.

Having messed with mine this last summer I concede it could be this cable came undone from the clip that holds it in place:

. This page will explain indetail how to adjust if need be: . On our older models there isonly Phillips screws holding glovebox in place. On my 91A as I assume it would be the same on your 90, you remove the glove box with Phillips screws and move the hot/cold lever around whilst on your back looking in the area of the radio/transmission hump area for the end of the cable you are looking for. If it is moving the flapper for the hot/cold mix chances are your problem is elsewhere. The recirculation/fresh air slider will be located behind where the glovebox came out and will be moved with the other lever.

The instructions in my 2nd link are very good to fine tune the door if it is not fully closing. Truly a 5 minute fix the second time! Nothing to it!

I have a '91Miata and anyone in the passenger seat with big feet invariably manage to disconnect the hot air duct from the heater. Any heat is blown onto the passenger side and nowhere else until I make the reconnection. Other than that the heater is excellent; to the extent I drive around in a Canadian winter with the top down and the heater on full blast. Peter Murphy.

I appreciate the quick and many replies telling me I should indeed be getting blistering hot air. That's what it boils down to basically, that I'm not getting very hot air. Now it's a matter of figuring out the cause.

The comment from Peter about riding top down in a Canadian winter and being toasty illustrates best the lack of serious heat from mine. I was cold on the way home and the heater could not overcome the situation.

For the record, I was driving top down, recirc air, 50-70 mph, on a

55F day (chilly) in So. Cal. The car was certainly fully warmed, it took an hour to get home and the air was no hotter at the end than the middle of the journey.

Doug

Don't use recirc with the top down.

What's the deal with that?

Doug

What use is trying to "recirculate" air in an open car? The system flows better in the "fresh" position. It's also quieter.

None of that is relevant to your lack of heat, though.

Gotcha Lanny, fair enough. My assumption that day was the somewhat warmer air taken from the foot well would be better than cold air, for the sake of getting the most heat possible.

Doug