mar3

iTrader: (8)

For the '84 and '85 cars, what would make the cruise control 'temperature-dependent'? When it's 80 degrees out or less, the cruise control works like normal for the complete drive to work...a 30 minute trip these days at an average 70 mph...indicating that the engine getting up to operating temps seems to be independent of the reason why the cruise control would stop working.

As mentioned, the cruise control stops working at 85 degrees or above. If the car has been sitting out in the sun and it's 90 degrees out, the cruise control won't work, period. Even if the car has been sitting for 9 hrs and had plenty of time for the underhood temps to cool down from the commute drive. If that temp is 85 or so, the cruise control will work for the drive home. Very maddening.

The only diagnosis I have done so far is spraying with bubbly soap on the vaccum line to the rat's nest and it doesn't show a leak or sucking action at the connections or along that vacuum line, so I'm stumped. If it was the control box, wouldn't it just be dead and that's it? But it only works when the temps are cool.

Help! I gotta sell this car, the yellow '84, in a month or so!

Siraniko

iTrader: (13)

Cant help ya there coz I dont even use the cruise control in my newer cars. For me, cruise control is accident waiting to happen. I prefer not to use it to keep me awake particulary on over-night gambling run to Las Vegas from Socal.

mar3

iTrader: (8)

Merely driving on public roads is an accident waiting to happen; it is up to the USER and how he/she uses the tools at his/her disposal that determines the particular level of danger associated with the use of that tool. If you smoke or use a cell phone (at all) while driving, THAT is more dangerous to everybody around you than using the cruise control feature...

So does anyone have experience here or not? I cannot be the first one to have this problem, can I?

Hades12

Maybe the box inside the car is kind of bad.

Rogue_Wulff

Perhaps it is the control box, under the storage bins. The ambient temp has a direct effect on the in-car temp, which could be affecting the controler.
There's only 3 main units of the cruise, the underhood pod, the switches, and the control box. Logic tells me the underhood part is likely not the problem, as the underhood temp is always rather warm once the engine is up to temp.
This leaves the other 2 items, which are inside the car. I am not that familar with S3 interiors, does it have a "Master" on/off switch in the dash or console like my S2 did? I dunno if that switch was bad, or just in the way, as a former owner has jumpered the connector, and deleted the switch. If it has this switch, this could be part/all of the problem, as well as possibly the multi-function switch in the column.

mar3

iTrader: (8)

Rogue_Wulff, you always think of something I didn't think about. I'll pull a schematic tonight for the '84 and see just where the feed wires go before they hit the underhood pod. I'll bet it's a bad ground or the controller isn't tightened up in back for a good ground. Thanks for the tip.

Rogue_Wulff

Damn, that reminds me. My cruise was acting flakey, and the control box was not mounted. I mounted it back down, and it has not acted up since.......

Hades12

I beat him by two hours and he gets the props. Oh what a world.

Rogue_Wulff

I spose I just splained things a little better?
Perhaps it's just cause I gotta gooder sig?

perfect_circle

to be fair, when you said could be kind of bad...that doesnt really help your credability jk

Hades12

Oh I see got to hold their peter while they pee.



And my sig Owns all.
.

trochoid

iTrader: (6)

My vote is for a bad control unit under the driver's bin. I ran across a couple in the shop last night. One looked brand new, the other was rusted clear through the case from bin rust. Don't want to see what the inside of that unit looks like.

If the control unit is good, then I would be looking at wires that are either moving in the heat or have bad connections. The muli-finction switch may also be the culprit.

mar3

iTrader: (8)

If the box was bad, then the cruise control wouldn't work at all, right? Electrical components on a board usually render the whole unit useless if a piece goes bad anywhere on it.

Best case scenario has a problem that is random and intermittent.

This problem is a function of temperature. The cruise control ALWAYS works when it's cold and never when it's hot. Right now, while we are starting our fine Texas mornings in the 60s or 70s, the cruise control ALWAYS works. Once the afternoon/evening sets in, we are now in the 80's or 90s. If it's 82 or so below, the cruise control will work. Any higher and it won't. A control box won't work crazy like that. I'm thinking the Wolff has hit something with wires and grounds or simply the MOUNTING of a good control box.

See the diff? Give props where props are due, dawg...

Hades12

My Pioneer CD player would do the same thing, Not work once it was hot, took about 3 months before it fully quit working.

LongDuck

Connector. Driver's side bin. 30 minute job.

Grab yourself some 'electronics spray' from Radio Shack and give it a shot when it's hot out - betcha it fixes it. As the temps change inside the car, it causes the wiring cables and wires to expand/contract allowing the connector to be shifted. Remove any tension on the cables leading into the copper-colored controller box, and unplug it/replug it several times and it should be good.

This is coming from a guy who's still troubleshooting his CC system, but I KNOW it's not the connector! HTH,

mar3

iTrader: (8)

Now, THAT I can appreciate! A step-by-step solution...Ill drop by Radio Shack and grab some of that cleaner. My Griot's Contact Cleaner finally ran out and the company no longer carries that product so I needed a new source anyway. Thanks, LongDuck!

Any modern (think 1990 or newer) auto CD player will have both electrical and thermal protection for the unit. If an electrical short or surge happens, it shuts the unit down to protect it. If it gets too hot internally, then the thermal overload protection shuts the unit down. They're designed to do that. I'm pretty sure it's safe to say that there is no thermal overload circuit designed into an interior-placed 1983 Mazda cruise control box...

ps...after not working on the drive home yesterday, the CC worked for the entire smooth 73 mph drive to work today......however, I know this because I've been forced to the Saturday shift again for the forseeable future...

LongDuck

Note that all these other guys figured it out, I'm just giving you some steps to do what you can to fix it.

Let us know if that works, usually we never hear back, and thus never know if that fixed it.