I want cruise control, but all I have so far are the unit by the ECU and the switch. What else do I need? I know there's an actuator under the hood that I need, but is there anything else? I have an 87 manual nonturbo.

 

Thats all you need. The three.

 

That's what I thought... But I was reading the factory service manual and I saw something about the clutch sensing switch and brake sensing switch in the cruise control section, and I didn't know if my car would already have those parts or if I needed to get them before I could use cruise control. Anybody know anything about those switches?

 

Here is a long, exhaustive thread about the p/s computer (btw, it's above the CPU, not the ECU.) While I don't believe that it has any specific mention about clutch or brake switches, you may find helpful 411 in it...

https://www.rx7club.com/forum/showth...threadid=39689

 

I retrofitted the 86 and 87 n/a and neither has the clutch switch to disable the cruise while driving. The tap the brake to disengage the cruise does work on both cars though. The clutch and brake circuits should be there on your car I THINK. I know the brake has to be there. I deliberitly disabled my clutch circuit on both cars.

Attached is a jpg of the cruise. What happens when you step on the brake, is that you put 12v to that OR gate in the cruise. The round, half moon looking outfit.

Its really just plug and play. The harness for all three should be in place.

As long as your able to tap the brake to disable it, that should be good enough as far as I'm concerned.

 

The cruise jpg:

Deliberately is the way to spell the word right in my first post. Sad. Can't spell worth a flip.

 

Can't leave this thread alone for some reason.

The brake switch is nothing more than the sw that already turns your brake lights on.

Actually the cruise will work just fine without both the clutch and brake switches. Its just that you would have no way to disengage the cruise while driving, except to turn the cruise switch to off. Not a good arrangement if you need it off in a hurry.

Just make sure you get the vacuum operated actuator for under the hood. Should have the electrical connector and one vac hose going to it. Vac hose goes on the intake manifold to the actuator. If you see a actuator without the vac hose nipple on it, I'd steer away from it.

Oh. The ECU is located under the passengers feet on the firewall. You have to lift the carpet up and take a metal plate off to access the ECU. Like the man said, the CPU is located to the left of the drivers left foot. Along with the cruise control box if you have one.

 

Thanks for the info HAILERS. Do you or anyone you know have the actuator that you could sell to me? And I actually wouldn't mind having that clutch switch too, if anyone's got one, just so I can try it out and see if I like it.

And if anyone happens to have this, I need the tiny screw that goes on the hinge part of the switch. I bought one off Ebay, but when I got it it was missing that screw, so the switch part can "lift" a little bit off main assembly and exposes the red wire inside it.

 

Not quite ..... check my closing comments about the switchs.



I've been down this path. Here is your complete answer as you scrounge through the donor car:

Actuator (be sure and get the vacume hose. You'll find a rubber nipple covering the vacume assess for it between the intake and the firewall). Note, the Actuator is different for a NA vs. a T2. Also, be sure and grab the mounting bracket as well as the bolts to install the mounting bracket to the fire wall et. al.

Dash Switch (Be sure and grab the mounting screws)

Brain (under the passenger side foot pan near ECU, as you described. Note, the mounting is different between a Vert and a Coup, but are interchangeable otherwise)

AND!!!!

Be sure and grab the brake AND clutch switch from the donor car. The correct brake switch and clutch switch are double switch design for the cruise. The non-cruise cars have only a single switch each. The wiring should already be in place to plug in these double switch's as well as the rest of the cruise electronics.

You definitely want these as you want the cruise to cut out if you press either pedel. Engine will fight you while braking otherwise, and the engine will rev up when you touch the clutch pedel otherwise.

 

Thanks for the info. If anyone has any of the parts for the cruise control (except for the brain unit and the switch, which I already have), email me or reply on this thread! I will buy! Thanks

Joe

 

I'll usually bow to what HOZZMANRX7 writes, but I've never had to do anything in the way of replaceing brake switches or adding a switch at the brake pedal on the cars I've added cruise to. I'm just a little puzzled about that statement. Double sw on the brake. Maybe I should have gone out to the car and looked before writing this. Must have been there already.

 

Hailers, buddy....

I would never contradict you if I wasn't certain. I normally take your observations as gospel also.

I added Cruise to my Vert, so know this to be true. Also, if you look close at the factory wireing diagram, you'll see the double switch indicated.

In doing my retro-fit, I had to go back to the donor car to get the correct switch's so everything would operate properly.

Best news is all the wiring to hook everything up should already be there. Just mount, plug in, and your ready to go.

 

I looked under my dash and I think saw only single switches. What do double switches look like? Anyone who can post some pics would be greatly appreciated. Here are the parts I need to complete the installation of cruise control on my car:

Actuator w/mounting hardware

Double brake switch

Double clutch switch

The little tiny screw that goes behind the main dash switch and keeps it from sliding out for installation or removal.

Anyone who can SUPPLY these parts, and again, I'll pay money, will be greatly appreaciated too

Thanks guys!

 

Don't have a Digi camera, but this should help:

CLUTCH SWITCH

The Cruise switch for the clutch is a single switch that mounts much like the switch for the brake light. (The only other switch for the clutch is mounted to the floor board and is what needs to be pressed in to start a manual tranny Rex.) It has a double wire connector mounted on a pig tail that in turn connects to your main wire harness.


BRAKE SWITCH

It is simply two switches mounted side by side inside one box like unit. Assembly mounts exactly where your current Brake switch mounts. Primary visual difference is that two separate female double wire connectors snap into the back of it. One for the brake light, one for the cruise.

To be clear, this specifically deals with my S4. Although they did somewhat change the wiring set up in a S5, I doubt there is a difference on this subject.

Don't forget to ask for the bolts to mount the Actuator to the chassis.

Also, there should be two screws to mount the dash switch. If you only see one place to mount, then one mounting tab is probably broken off. If so, you should replace it to mount properly. Either way, don't tighten too tight as the plastic gets brittle over time and breaks easily.

Have fun.

 

My Cruise control is intact in my garage if anyone wants it.

 

While we are on the subjest of cruise control myne has just stoped working for no reason ive looked in the manual and it says there is fuse for it but i cant find it and its not in the fuse box?? anyone got any ideas or should i be looking at something else to do with the c/c???????

 

Me and HAILERS also had this conversation about two months ago: besides the speed limiter of 180kph (which can be removed), there is also a 180kph speed limiter on the Cruise Control, meaning that it wont engage at speeds above 180kph, and the speed it will hold can be no more than 180kph. Anyone knows how to disengage THAT ?

 

BOOSTED ROTORS.....is that for a turbo? Probably yes by your profile. I'd be interested. I need the electric actuator for a turbo into a n/a swap I might finally do someday. Got the engine and transmission, just no motivation. Actually I'd want the actuator, *computer* and switch. Probably can live without the computer and sw.

MAZD07....I attached a jpg of the wiring schematic for cruise. It shows a 7.5 amp fuse. Its amoung those in the crew compartment near your left foot. Take a look at all those and if they are all good go check that the cable is connected to the throttle linkage, the vac hose is connected to the actuator and manifold and the electrical connector is attached to the actuator. If that does not solve the problem: Do you have a light indication on the switch???
That jpg is for a turbo, the manual did not have a n/a schematic in my book. But both should have a fuse near the left foot.

 

is that the vacume hose is disconnected somehow.

Although factory set up is the hose is connected directly to the intake manifold, sometimes it is connected to a plastic "T" connector on another vacume line. Heat from the engine makes plastic pretty darn brittle. So, breakage is common.

 

Any on know if a 89-91 Cruise control switch work on a 86 Sports.

 

Sorry a ment a 89-91 Cruise control kit. I saw one for sale at a dealer.

 

Mine (86 NA) won't keep the car above 160 km/h.