• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

1992 cruise control wont engage

J

jeeptorino68

NAXJA Forum User
Location
Lebanon OR
it was slightly intermittent at first, as in it would engage and then disengage and then re engage, i thought it was the multi function switch (turn signal stick) and i replaced that with no benefit. i also tried a used brake light switch, and have tried a replacement vacuum servo.
i have no vacuum leaks

i ran accross this in the FSM:
NO CRUISE CONTROL WHEN SET BUTTON IS PRESSED & RELEASED
Check for: blown fuse, no vacuum at servo and/or defective
servo, disconnected speed control cable, brakelight switch out of
adjustment, faulty electrical circuit, faulty Park/Neutral switch
input to PCM, faulty PCM.



anyone have any other ideas?
i have tried adjusting my NSS after i cleaned it, it will start in park or neutral, but the reverse lights never come on. well almost never they sometimes very rarely will turn on.


any ideas?
i really need the cruise working. well i dont need it. but it would sure make it alot better
 
ill have to see what the junk yard wants for one, if its expensive id rather not chance it, i might try cleaning and re assembling it again this weekend.
 
jeeptorino68 said:
i ran accross this in the FSM:
NO CRUISE CONTROL WHEN SET BUTTON IS PRESSED & RELEASED
Check for: disconnected speed control cable
Click to expand...

Are you sure. the connector on mine keeps slipping off. I think it's broken (the connector).

Hasn't been troublesome enough to worry about...not alot of long freeway trips, mostly 2 lane "mountain" roads.
 
you mean the steel cable that attaches to the throttle body?
mine is secure las ti checked when i was trouble shooting the cruise last time.
ill double check, but i never had a problem with it before
 
Does the dash light come on when you try and engage the cruise?
 
not sure if you stated it, but did you check for proper vacuum, and does it hold? The vacuum accumulator is prone to leaks, and the hard line over time (heat cycles) becomes a brittle.
 
962drrhino said:
not sure if you stated it, but did you check for proper vacuum, and does it hold? The vacuum accumulator is prone to leaks, and the hard line over time (heat cycles) becomes a brittle.
Click to expand...
I think he addressed that too...

jeeptorino68 said:
... and have tried a replacement vacuum servo. i have no vacuum leaks
Click to expand...

...yet it's still not there. Since you said the reverse lights never come on I might suspect the NSS as well, but (not sure on HO models) do you have a 5A or 7.5A fuse marked TRANS under your dash??
 
yea liek i said it holds a good vacuum, if i un-hook a vacuum line hours after shutting it down, or the next day there is still vacuum in the line


ill check the trans fuse under the dash, i dunno if its 5 or 7.54 amp

whats the difference (other then the amperage rating) im assuming one fuse rating means i have XX equipment while the other means something else?


ill mess with the NSS this weekend
i might try stretching the little springs that puch the contacts out. maybe they are making contact in park/neutral but for some reason cant reach far enough for reverse and drive. to turn on the revers lights and to let the cruise know we are not in park neutral or reverse.
 
Uh-oh, I had a 4A fuse that I pulled, because for some reason the brakelights all of a sudden stayed on on day. I didn't even think of that!

My NSS is still bad and the junkyards will only sell them with trans.

"How about without the transmission?"

"Okay, $400."
 
ok well i took out the NSS and cleaned it again, the little spring loaded pieces were already gummed up from last time i serviced it...
i used brake cleaner this time and white lithium grease, got the revers lights working and it starts in park/neutral.

unfortunately that did not fix the cruise.

i did notice that if i rapidly push the button on the end of the turn signal switch(the set button) i can feel a slight tap in the accelerator pedal, like it is trying to set the throttle but then releases. the faster i push the button the faster i can feel it in the pedal...
im thinking that maybe there is some kind of loose connection.. or?

one other question, the 2 relays under the dash.
i know one if the horn. what is the other?
if its the cruise then maybe that relay went bad. my horn relay went bad one time so maybe?
 
working on the cruise problems for my 92, i found that i do have the vacuum release on the brake pedal.

where is the cruise control module? as pictured below
cruise-control-system_html_2e371ea3.jpg


the brake light switch sends an electrical signal to what i think is a electric servo kinda thing in the vacuum line, this is all under the dash, the vacuum hose disappears into the middle of the dash behind the heater...

how do i test this little vacuum thing? i think it works because when i shut off the jeep the first 4 or so pedal pushes, you can hear a hiss of a release of what i think it vacuum, but that could be the booster too....


any other ideas to help?
i tried testing the brake light switch.
but the continuity didnt match the FSM instructions

released
1&4 Y
3&6 Y
2&5 N
depressed
1&4 N
3&6 N
2&5 Y



mine had continuity at 1&2 and 5&6 when depressed....

ill keep testing
i know the cruise servo under the hood is good, as well as the cable.
 
You said you replaced the on/off/set switches right? Did you replace the wiring harness from the turn signal stalk down the steering column? 90% of the time it's the little wires that get broken where the turn signal stalk moves up and down. For some reason, GM used solid wires instead of stranded wires. I replaced mine with a computer USB cable wire. 4 wires and nice and flexible.
 
on a 92 if I can remember the wire gose all the way to the bottom on the column from the switch so it shouldnt be broke unless it got cut some where in his install
 
yes i replaced the multi function switch (turn signal with cruise control) i will double check continuity in the wires, i have instructions in PDF for that.

anyone know where the speed sensor wire is located? or the cruise control module?
 
On the vacuum side of things, the CC and HVAC system work off the same vacuum circuit. It originates from a port towards the rear of the manifold, and becomes a hard plastic line running along the firewall in the engine bay. There is a tee near where all the HVAC stuff goes into the firewall, and a branch goes through the firewall into the dash. The main line continues along the firewall underneath the windshield fluid tank, then down along the passenger side where there is another tee, with a branch connecting to the CC vacuum motor. The main line then goes down under the battery and into the vacuum canister behind the bumper. At least that is how it is run on my '92 Laredo.

I know this b/c I just looked at it all yesterday, since my HVAC vents were acting funny. Turns out the vacuum connection to the nipple on the canister was off. Plugged it back in and now my vents work properly. Since this vacuum circuit also serves the CC you might check it out. Especially if you have any issues with your vent doors not opening/closing right.
 
all the vents are operating fine, and the vacuum line and canister are fine aswell.
it seems ihave a cruise problem that no one else has had before, or atleast no one wants to figure it out and they just went without cruise.


i think it is electrical, my vacuum canister holds good vacuum, and the HVAC works properly as far as switching vents....
thanks
 
jeeptorino68 said:
yes i replaced the multi function switch (turn signal with cruise control) i will double check continuity in the wires, i have instructions in PDF for that.

anyone know where the speed sensor wire is located? or the cruise control module?
Click to expand...


If you DIDNT replace the wires in the column, then I betting thats where you problem is. Look at the base of the turn signal stalk where the little wires are. You will probably see a broken one or two.

happy fixing!
 
You must log in or register to reply here.

Similar threads

D
1996 4.0 No Crank, Starter Works When Jumped
Replies
16
Views
233
DirtySouthXJ
D
M
1992 Electronic Control Module - Can these be purchased new anymore?
Replies
8
Views
171
lawsoncl
L
C
1996 cruise control install...not working
Replies
6
Views
1K
Saudade
Saudade
X
drivers door switches only work on accessory mode
Replies
7
Views
1K
XJJeepNewb
X
D
98' Cruise Control inop.
Replies
2
Views
1K
dktool
D
Back
Top