Install NB Factory Cruise Control

I just finished installing the factory cruise control in my '99 (NB)
Miata and thought I would share some observations about installing the
various components in an NB that differ somewhat from either what is
written in www.miata.net Garage/Interior/Factory Cruise Control
Installation, or the factory Workshop Manual. I have submitted all this
to Miata.net but thought if you're contemplating this mod, you might
find this interesting. It assumes you have read John Minor's fine
article on doing the mod to an NA.

MASTER SWITCH - There are two variations of this switch in the '99. One
is for cars that have fog lights, and it has two push button switches in
a single module. The other is for cars without fog lights, and it is a
single rocker switch in the same size module. I mistakenly ordered the
dual switch, thinking I would eventually install fog lights, only to
find that it has a different number of pins than the connector on my
non-fog wiring harness. Unless you want to do some cutting and
splicing, order the right switch!

Also, if you are replacing the factory blank with a master switch, I
would NOT go to the trouble of trying to release the blank by squeezing
the hook clips from behind. It's nearly impossible to get to without
dismantling lots of things in the way. Instead, I would pry and 'worry'
the thing out from the front, even if you have to break it a little.
You will find the connector for the new switch living in the back of the
blank. Simply unplug it from the blank, plug it into the new master
switch, and push the switch back into the rectangular hole, making sure
you install it right side up. Once it clicks into place, it's there for
good!

VACUUM SERVO - Installation is very much as described, except that there
are only two fasteners - one bolt that goes into a threaded hole in the
fender and one nut that goes on a stud that's already there. The servo
I bought (on ebay) had five rubber grommets on its mounting bracket, but
only two were used for mounting purposes. The others simply serve as
additional cushioning. My unit was off an '01 and came with both the
actuating cable and the vacuum hose attached (nice). There is a square
plug in the firewall that pops out, along with a square knockout in the
fiber insulating mat inside that is easy to push out. The cable simply
snaps into this hole and can live there indefinitely until you're ready
to deal with the pedals. There is also a support stud on the cable
housing that snaps into a diagonal square hole on the inboard side of
the brake fluid reservoir. The vacuum hose goes across the upper
firewall and plugs into the back of the intake manifold. Mine had a
little rubber stopper covering the fitting on the manifold which I
simply removed. What was a little confusing were a couple of support
studs on an insulating sleeve that came on the vacuum hose. I couldn't
find any holes that would accept these, so I went on ebay where you can
find pretty good engine compartment shots of just about any car they
might have for sale (good to remember). Anyway, I figured out that the
'01 had the cable routed slightly different from the '99, and I simply
used tie wraps to secure my hose in a manner that appears to be correct
for my model.

CONTROL MODULE - The module installs exactly as described. If you have
a Workshop Manual, it will lead you on a wild goose chase where you have
to remove the key interlock mechanism. I have no idea what that's
about, as this is nowhere near where the module mounts. I think it must
be a misprint. The 'HOLD' indicator is actually a 'CRUISE' indicator on
NB's (to the left of the fuel gauge), and it requires no special wiring
for it to work!

STALK CONTROLS - This went pretty much as described with some minor
variations. I chose to remove the air bag and the wheel. It's really
not hard at all. The air bag comes off with just two 10mm bolts on the
NB. I find that if you loosen the big nut on the wheel without
completely removing it, you can then give the wheel a few good jerks to
free it from the spline without shifting its position. After that you
can center it carefully and gently remove the nut and the wheel. Next
is the clockspring, and as long as you're careful not to turn it after
it's removed , you won't have any problems. What was the biggest
problem for me was removing the bottom panel under the steering column.
It is secured by 2 Phillips screws near the bottom edge of the dash, and
two 10mm nuts that are fairly difficult to get to. I found that the one
on the left was easiest to access through the fuse access hole after I
loosened the fuse block and pushed it out of the way. The nut on the
right can be reached (with some difficulty) from behind the bottom edge
of the dash. I used a small 10mm combination wrench on both. Once that
cover is off, the connector is easily accessed, and the cluster switch
is simple to swap out with the new one.

PEDAL ASSEMBLY - This proved to be the most challenging for me, as there
were some differences in the assembly I bought on ebay and my existing
unit. I decided it was going to be too much trouble to change out the
bracket and both pedals (gas & brake), so I decided to make the newer
fuel pedal work in the old bracket and simply replace the old stoplight
switch with the newer stoplight/cruise switch. The problem was that
the newer bracket had nylon bushings where the gas pedal pivoted and my
bracket didn't. Newer NB owners shouldn't have this problem. The holes
in my bracket were the correct diameter for the pivot rod, but no room
for the bushings, and the old pedal didn't use a circlip to secure it.
Instead it had a 'top hat' (for lack of a better term) press over the
end of the pivot shaft. This had to be pried and 'worried' off with
considerable foul language. After I got it off and tried to insert the
new pedal shaft in the holes, I found that there was too much side play,
as the bushings in the newer bracket were shouldered and gave some side
support. So, I had to find two washers that fit reasonably well over
the pivot shaft and were about a thick as the shoulders on the nylon
bushings. That did the trick. The only challenge after that was
putting the circlips on the pivot shafts of the pedal and the secondary
'cruise arm' without losing them. I found that needle-nosed pliers
worked well for this. Don't forget to put the pedal spring on (as I
did) before you install the circlip. Oh, and the nylon bushings for the
secondary 'cruise arm' fit perfectly in the original bracket. The
cables simply snap into the pedal arm and the cruise arm, and I did that
last.

The stoplight switch is easy to replace, and the new one should be
adjusted far enough into the bracket that the switch plunger is
completely (or almost completely) compressed when the brake pedal is
released. If you don't do this, the cruise will not engage. Oh, the
little two wire cruise connector can be found tucked away about 10
inches back up the stoplight cable. It took me 20 minutes to find it.
It plugs into the stoplight switch next to the stoplight cable.

Finally, it's worth mentioning that the clutch switch that prevents
starting without depressing is also tied into the cruise circuit, i.e.
nothing to do here. It's already done. If you depress the clutch
pedal, the cruise disengages.

I would reckon that my total time for this installation was about 8
hours, but part of that was due to the fact that I was/am slow, and I
was having to discover quite a few things on my own. I'm very please
with the end results. The cruise control performs exactly as you would
expect from factory unit. Anyone interested in doing this mod is
welcome to email with questions.

--Geary Morton
'99 Emerald Mica
.

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