Cruise Control

[Burntboot]

So I just replaced the TPS and cleaned the throttle body, all back together and running great.
Though I no longer have cruise control, I know I am missing something stupid, either an electrical connection or a vacuum line but for the life of me I can't see it.
Anyone know what lines/plugs I should be concentrating on, manual is very clear on diagnostic rituals but short on plumbing pictures.

Thanks

[timsrv]

I'm a bit vague on the cruise control circuit but I don't think it's interconnected with the TPS circuit. My guess is it's unrelated (just bad timing). Check to make sure your brake lights are working and check your fuses. Hopefully it's something simple. Tim

[Burntboot]

Thanks Tim.
I did double check everything at the TB, nothing amiss there.
I had used the cruise the day before I pulled it apart so am quite sure it is self-inflicted pain.
I also had the pass seat pan out and did a several things while I was there.
Do you have any idea where the cruise actuator is located, I could not see it, but it has to be in there somewhere, I suspect I have accidently disconnected it.
I don't seem to have any vacuum leaks, not electrical faults, all fuses good and the brake lights are functional. The light on the dash switch comes on, just no response from the set/coast switch.
Just sucks as I have some mega-driving to do this weekend, cruise would have been really nice.
BB

[timsrv]

The cruise control actuator is under the footrest for the driver's left foot. It's connected to the throttle pedal mechanism via a cable. All the wiring for it is pretty much under the dash.

[Burntboot]

Thanks Tim, haven't had a chance to dig back into this yet but am beginning to suspect your hypothesis on coincidence might be right as I have no drivability issues other than the cruise being dead.
I was going to check to see if the cable from the cruise is still connected to the pedal but there seems to be a cover over the pedal that I cannot see how to remove, any hints on that one?

On a side note, since the cruise stopped working, the clock has started to keep correct time.
Go figure.

[timsrv]

I've had the gas pedal assy out before, but it's been a long time and I can't remember what tricks are required. If you illuminate the area with a good shop light it shouldn't be all that hard to figure out. Tim

[filterway]

Hi all,

today i drove my van from the seller'home to my home. I used the cruise control. Sometime the cruise don't stay engaged.

i know where the components are located (left foot of driver) and i'm asking if someone can help me with this issue.

thanks

[timsrv]

There is a sensor in the brake fluid reservoir. If fluid level is low the cruise will not engage. If it is just slightly low, it can cause intermittent issues with the cruise control. Top off the brake fluid on side of dash near driver's door jam then try it again. Tim

[hunziker87]

Burntboot — Did you ever solve your issue? Mine has done the exact same thing and I was wondering if you have any advice before I tear into the issue, thanks!!!

[Burntboot]

H87 - It came back to life all on its own, that is, until the actuator cable snapped.
Cables are NLA, by the way and Auto/MT list different part numbers and no suppressions.

Found an 89 auto at the local yard that had an intact cable, while I did have to max out the adjustments, it works fine and I haven't had a problem since.

The actuator is indeed under the left foot rest, the cable goes up across the bulkhead, snaking behind the steering column, then makes a fairly sharp turn into the pedal box assembly.

Mine snapped right at the junction to the pedal box, but it was obvious that 2 strands had let go previously.
The gas pedal always felt a little weird, but I just assumed it was a nature of the beast sort of thing, after the cruise cable broke, it worked much better.
Once I replaced the cable, the weird feel never returned, so I suspect the previous failure was due to the cable binding.
BB

[spacecruisers]

Been putting many hours of work into my new van fixing things here and there.

My van is an 87 4wd 5-speed and has cruise control but it isn't working. There appears to be a click sound when I press it but maybe I'm dreaming.

anyway, I've never worked on a cruise control system before so what should I look for to diagnose and replace to see if I can get it working again? Is there a common point of failure (maybe the switch is bad?)

[Burntboot]

Shmi - the factory manual has diagnostic steps and codes fully outlined.
If my experience is anything to go by, check the cruise actuator cable where it turns and runs into the pedal box, thats where mine was frayed/split.
Auto and manual cables carry different part numbers but i was able to get an auto cable to work in my manual van, not sure if it would work the other way around.
For what its worth, the actuator controller is mounted under the left side foot rest, cable snakes thru the lower dash/steering tube/pedals and enters the pedal box from the "front".
Pita to get at.
If the green light turns on and the system appears active, check the cable.
BB

[spacecruisers]

Fortunately I've got the dash all torn apart - removed it completely to fix some cracked tabs and stuff as well as replace the stereo and speakers. I just kept going and suddenly it was all off

i see the cable you're talking about. haven't removed the foot box but it appears to be in good shape... i can take a closer look. however, now that you mention it, i don't recall ever seeing a green light activate when pressing the switch.... bad switch maybe?

found the pages i need in the service manual. just thought i'd check on here and see if there were any commonalities when it comes to failure of the cruise system .

[Megadysart]

Is your brake fluid/handbrake light coming on/staying on? The cruise control system won't work if the brake light is coming on or staying on. My van has a small clutch master cylinder leak and whenever the fluid gets too low I lose cruise control until I top it off and the light goes away.

[spacecruisers]

interesting! the PO had the handbrake wire disconnected because he said the light was always on.... i'll try reconnecting it and figuring that out. I had no idea they were related but it makes sense! Thats probably why the cruise isn't working! Thanks for the tip!

[erik]

Hi all! We recently discovered that our '85 Van's cruise control does not function. Some limited testing done so far was to pull the Cruise Computer and check the power, ground, stop light, brake level/parking brake and control switch signals. All those appear to be good. What should I check next? I have the wiring diagram but am not sure where the actuator is located or how to test it. As well, I am not sure what the Cruise Control Stop Switch is or how to test it. Thanks!!!

Update: I located the actuator underneath the driver's side footrest. Pulling on the cable causes the throttle pedal to depress. How can I test the actuator unit?

[Burntboot]

I have little knowledge of 1st gen trucks but would suspect it is similar in operation to the later models.

When you turn on the dash switch does it light up?
Have you checked the brake fluid and emergency brake as either one will interrupt CC operation.
(The light should come on momentarily while the instrument pack does its check function, if it doesn't the bulb is likely burnt out)

Manual would be handy at this point as it will have diagnostics for cruise detailed
BB

[spacecruisers]

Just to update on this thread, my parking brake cable was disconnected. Reconnected it and it still wasn't working. Whatever. Fast forward to a couple days ago when I tore the dash off again, I noticed one of the terminals in the harness that plugs into the cruise button had been pushed out. I bent the tiny metal clip and pushed it back into the connector, and tested the button. The cruise light comes on now! However, it didn't actually set the cruise when I pushed it. I would drive at 60 in 5th gear and push the cruise button, the light would come on, id take my foot off the pedal, but the cruise wasn't engaging. Once I took my foot off the pedal the van immediately began to slow. Maybe I'm missing something dumb as I've never had cruise on an old stick shift toyota like this, or perhaps theres another issue present on top of the wiring issue I resolved.... I'll double check the cable to the actuator as burntboot suggested and update if I find anything.

[djshimon]

After you press the cruise button in try turning the end of the cruise lever-one way it sets the speed and the other way I think raises it. I thought mine was broken too.

[mr_josh]

The switch on the dash is just the cruise master On / Off. After you turn on the master, turn the cruise knob on the end of the wiper stalk down (it says Acc, maybe the printing on your knob is worn off?)