Cruise control not applying drive

My cruise control doesn't work. I want to fix it.
-It turns on just fine, the light appears on the dash
-It also appears to engage just fine if I pull the set/coast or resume accel functions. Light appears on dash. It also goes away if I brake. As expected!
-It just never actually drives the car.

I've been hunting around the FSM. It seems like it could be the actuator, which requires testing with a 12v battery (something I know nothing about), or the vacuum hose the system apparently uses.

Any info anyone can provide about this so I know where to look, before I start dismantling actuators and buying batteries and the like?

 

Huh? it doesn't automatically drive teh car for you , it needs a brain 2 arms and 2 legs to drive it.

 

Bring it over and I'll fix it for you.

 

NO!

I'm not sure about that vacuum hose. I don't think it's explicitly mentioned in the FSM, and I'm not quite sure what I'm looking for.

It's such a bitch, you can't test it because it only works above 30km/hr :\
I mean, I can look at the actuator, it looks great. But the only way to test its functionality is to take off the silly thing and faff around with a battery :<

 

dont have to take anything off.
manual is pretty specific on how it works and how to diagnose it.
Disconnect your cable to the throttles, unplug it and run wires from your battery to test function. Pretty straighforward stuff really

Oh, and if your motor and actuator are fubared, source a setup off of a Maxima (300zx operational ones are becoming pretty scarce)
*Ultilise your existing bracketry
*Plug to the cruise vac motor does need changing over, but all wire colours etc are the same. Simple soldering job really
*Actuator cable needs swapping over, as the maxima one is too long from the cable to the adjuster. 2min job.

When working, make sure you adjust your cable properly to the throttle linkage. Make sure there's no slack in it and that its not holding the throttle bodies open at all. Properly adjusted and working, and the cruise is sensational.

 

Ohh I can go straight from car battery. Sweet. Just need some wires.

Thanks for the advice. Where do you find Maxima parts? :|

 

wreckers my friend .

Used speaker wire with a couple of small insulated alligator clips on each end to testing.

For reference, turned out my entire assembly was stuffed. Motor would spin, but wouldnt create vacuum, and diaphram in the actuator was fubared as well.

 

My local wreckers only has old shitboxes, up to the N15 Pulsar. I don't think they have any Maximas, they tend to get pretty shit cars.
Except for the Z31 50th that showed up recently...

 

i feel rejected

 

would you take any of my advice , you dont have to , ?

 

Nothing wrong with your advice I'm just interested in doing it myself.

I did some proper poking around. Found what appears to be the above mentioned vacuum hose, a little black hose linking vacuum pump to actuator. Sort of. It isn't actually affixed to the actuator at all! It appears to have snapped at the point where it meets the actuator.


The issue now, to replace that hose I do need to take apart the actuator I believe. How do you do this? It has no screws. It's just a little mysterious black box.

 

So it's snapped at the diaphragm end (right end of the hose in this pic)?

 

No, the left end in that pic.
In fact mine is the exact opposite of that pic and the round thing that the hose is attached to in the pic is the thing that I need to dismantle.

 

Not sure how opening that up would go, is the snapped hard plastic tube still inside the end of the rubber hose? Maybe you can extract it and glue it back on. You could run a match stick or something around inside so the glue doesn't ooze into the tube and block it

 

well i have the system here , if you need it let me know , and yes it works

 

I don't think so, it seems the rubber hose has snapped away. There's certainly no hard plastic bit attached to the end of it. I think what's left in there is more rubber hose.
Maybe glue would be an option. It seems silly to replace such a thing because of a simple rubber hose failing.

If it does come to replacement I'll let you know, xtc

 

I would be taking badxtc's advice.

Cruise control functions on a small amount of vacuum that the pump creates to that diaphram. If the nipple has snapped off of the diaphram, I'd be replacing it.

Hell, unless youve gone through the 2-wire procedure on the vacuum pump to ascertain condition, and youve been offered a working unit from a reputable member..... take that shit Theyre not worth that much

 

You might be right. Depends how much he wants for it

 

hhahahahahah

how much is a working C/C worth to you ?