Cruise control problem

[bigred]

You know I just realized something. That fuse 35 has no power to it unless the brake is pushed, which makes sense for the shift interlock but not the servo. So why would I chase that wire that makes no sense.

 

[ttocs]

if the connection to the interlock is good, but the connection to the servo has failed somewhere between(like at the clutch jumper) we will not see power at the wire on the servo.

 

[BHernandez]

You shouldn't need yo cut the wire to test the servo. Use a power-probe. You can rent on from your local auto parts store if you don't want to buy one. Have someone in the car with it running. Apply the power-probe to the servo and the second person turn on the cruise. Even in park the dash indicator should light up green.

 

[bigred]

But there would be no power to that without the brake pushed.
There is no dash light for the cruise as others have said, plus I've had that out of the dash and there's not even a place for it which is normal for this year or model.

 

[ttocs]

I agree he should not need to cut the wire and it is a last resort style of test to see if that wire is the problem and why it came with a warning not to try in trafffic.

If you look at the wiring diagram you supplied the clutch relay when activated simply disconnects that green wire so that the servo doesn't see power, doesn't see ground or anything so it shuts everything off. My theory is that wire is disconnected somewhere after the shift lock since there is no power on it with the brake pushed so it thinks the clutch relay has kicked in and will not let anything activate.

 

[bigred]

Yes I agree with that but no idea which wire at all. I got that diagram off this site in another thread. And it's not uncommon to not have a cruise light on dash. Found that out from v6 forum, a bunch of people don't have that.
What year is your Mustang and does it have that dash light?
Maybe I can look in the wheel well and see what that green wire ends up looking like. It's most likely one of those other harnesses in there, don't want to have to do the wheel well thing again though but you can see some in there. I'll look tomorrow, no promises though.

 

[BHernandez]

I have a 98 GT w/ EAOD Trans. I've replaced my servo twice over the past twenty years. On mine, there is no circuit wiring for the clutch relay. On the manuals I've seen, the clutch relay has a green wire that plugs into the servo harness. All it does is cut the ground circuit to the servo, thus disconnecting the ele tronic throttle stop. Not so on the automatics... usually. With the automatic, you only have the brake switch relay, present on all cruise control equipped cars. Silly question; but has your cruise control ever worked since you've owned the car, or did you buy like this?

 

[bigred]

They're wrong about the wire color there at least with an automatic. Yes I know it does the same as the brake. I'm not new to working on cars just cruise control wiring. I usually have always fixed my own autos, motorcycles tractors etc. I don't trust most mechanics.
Yes cruise worked no problem till a month or so ago, that's why I changed the servo and brake switch since no bad fuses. I've had it two years now 135000 miles.
You have a lot more power than mine but mines not bad.
Getting anything from that refinery fire there?

 

[BHernandez]

Nothing yet. Filled up today at $3.45/gal. But I suspect it won't stay that way long. Rumors are that our fuel normally from Texas will be rerouted north to help cover the shortage.

 

[ttocs]

I have never known of a dash light for the sn's, at least not for my 94.

I have a 98 GT w/ EAOD Trans. I've replaced my servo twice over the past twenty years. On mine, there is no circuit wiring for the clutch relay. On the manuals I've seen, the clutch relay has a green wire that plugs into the servo harness. All it does is cut the ground circuit to the servo, thus disconnecting the ele tronic throttle stop. Not so on the automatics... usually. With the automatic, you only have the brake switch relay, present on all cruise control equipped cars. Silly question; but has your cruise control ever worked since you've owned the car, or did you buy like this?

if you look at the diagram on the other page, there is a jumper that they put in place of the relay when it is an automatic.

 

[BHernandez]

Makes sense. Keep as much of the wiring the same as possible. That's why I find it strange the many V6's don't have a cruise control light on the dash. I thought the instrument clusters were universal, only different speedometers for different models. When I turn on my cruise, there is a tiny green spedo symbol that lights up in the instrument cluster. Just let's you know the system is active.

 

[bigred]

What other page, what you have? Take a pic and post it on here.
But as you can tell by the pic I took it's always been that way. That was done by Ford when built.

 

[ttocs]

I started installing audio/security in the 90s and just learned not to be surprised that for some reason some of the wire colors given to me were not correct. I think if/when they ran out of a wire color they just threw something else in.

 

[bigred]

I wish there was a green wire there would make that a little easier. I really find it hard to believe that that wire would not be complete anywhere since all those are covered in conduit for lack of a better word. Not going to be easy to follow.
What about the orange power wire out of the servo? I've seen that one as it's red and green that comes from 33. Still can't believe that either one of those would not be connected. Appear to be complete wires and where they go I don't see how they aren't connected and wouldn't have a break in them anywhere.

 

[ttocs]

20-30 year old wiring can come apart for many reasons both from just corrosion/age to a shitty mechanic that didn't care during that time. It absolutely sucks to trace wires but unless your willing to troubleshoot the problem or rerun the wires then its what you are down to. If the orange wire was bad it could also cause a problem. You can also use a meter to test for continuity on wires if you can find the same wire in two places. The plastic around the wires isn't nearly as bad as the 20 year old tape....

Personally I would find out where that connection to the shift lock is and I would check it(possibly around the shifter?)

 

[bigred]

We'll see eventually. I know there's ground at the servo but no power at the orange wire there.

 

[ttocs]

We'll see eventually. I know there's ground at the servo but no power at the orange wire there.

and you have tried both with and with out the brake on? Just making sure

 

[bigred]

No I haven't. Just with ignition on or off. But I will.

 

[bigred]

At that plug where the jumper is the wires are blue/red one side and white/pink on the other side. The green wire does come through the firewall but hard to tell where it goes from there. There are a few green wires in that mess.
I hate auto wiring, house wiring no problem..lol
To bad the schematic doesn't have those color of wires on it. The second color the way I put those colors in here is the stripe, the blue and white are the predominant colors.

 

[ttocs]

narrowing down which wire is which is what the meter is good to help with. There are a few ways to do it and sometimes you don't even need to see the meter if it has the diode check option. The symbol for a diode is a triangle/arrow with a line on the end of it and sometimes it will also have a little audible/speaker symbol as well. If you put the meter selector on it and then touch the test leads together the meter should/will make a beeping noise to tell you that they are touching. Just stab the wire on one side and then get the lead to the other(you might need an extension wire) and then start testing wires on the other side till you hear the beep.

After that the resistance/Ohm meter is another great way to test but you will need to see the meter display to do this and that is sometimes not possible.