1999 Mounty 5.0 aka My Great Bad Idea

[97Sandbox]

Lol 1999 has no auxiliary relay box there...sneaky buggers.

 

[CDW6212R]

The diagrams for 1996 look to be saying the relay box #3 is the large main Power Distribution Box, which is the one and only big one in my 98's, and my 99. That 96 manual is a little different, that shows an aux relay box forward near the battery, which isn't there in 98+ Explorers. Mine has that one under the air cleaner, it has the blower motor relays, as well as fog light relay.

 

[97Sandbox]

I dug under the dash of the Mounty more and found the "brake applied input" wire (tan/lb) was looped between two of the bulkhead connectors. I checked under the dash of my Sport (factory manual) and there is only one tan/lb wire going through a bulkhead connector and it's the one coming from the clutch position connector.

Looking back under the Mounty, one side of the loop is crimped together with the signal wire from the brake connector (red/lg). Maybe that's not S147, but it's definitely a splice of the suspect wires.

I undid the spliced side of the loop and will take the Mounty out for another test run tonight.

 

[97Sandbox]

Disconnecting the splice at the bulkhead didn't make any difference: brake still kills cruise, but clutch doesn't.

I'm frankly not sure how the circuit above would allow the clutch by itself to turn off cruise because it shows the brake switch working by being normally grounded then it will pass through 12V to the servo when the switch is closed. But the clutch switch is normally closed, so it's grounded through the brake switch as long as the brake is not pressed. The circuit is open if the clutch by itself is pressed. There's nothing in that circuit that shows how the clutch could send 12V to the cruise servo (unless brake is already pressed).

I feel like I'm missing something. It would make more sense to me if both the brake and clutch switches were normally closed and wired in series, then opening either one would cut voltage at the servo. But that's not my understanding of how the brake switch works.

 

[allmyEXes]

Maybe you need a switch, Like a 1974 Chevy truck brake light switch, 2 blade type, that will close when you press the clutch and wire it to the switch at the master cylinder to disengage the cruise.

 

[97Sandbox]

That could be a workaround.

What's odd to me though is the factory manual with cruise setup (in my '00 Sport) does disengage cruise when either clutch or brake is depressed. I'm just not sure how.

 

[97Sandbox]

I've continued reading through wiring diagrams and I'm still not having any breakthroughs. I'm confused because the speed control diagram (earlier post) shows the brake pedal position and clutch pedal position switches in series, but this other diagram shows them in parallel:

I thought I was onto something when I saw the inline connector diagram calls for a manual-specific instance of the #306 (tn/lb) wire merging with a #644 (dg) wire:

But then I went out and checked my Sport and I see no such dark green wire at the connector where the tan/lt blue one goes through. Also, I can't find #644 referenced anywhere else in the manual.

Seems like something isn't quite adding up...

 

[Josh P]

Looking at that one diagram 59-6, was there a shift lock actuator and it went away?

 

[97Sandbox]

Yes, I removed the actuator along with the column shift assembly before I added the manual-style key interlock. There's actually a dummy connector that the abandoned shift lock actuator pigtail clips into to keep it out of harm's way -- that's how it is on my Sport, so that's what I copied on the Mounty.

 

[410Fortune]

So the brake on off circuit cancels the cruise right? Press in brake switch grounds. Cruise deactivates? Do I have that right?

If so then just wire up the clutch switch the same way … clutch out no ground, clutch in ground would cancel the cruise
install it on the same boo wire?

Just spitballing without checking any diagrams (fleeting thoughts)

 

[Turdle]

If a boo switch could just be wired in parallel, it would work fine. Cruise control doesn't care really, just needs the off ground.

 

[97Sandbox]

Brake pedal position (BPP) switch still kills cruise as it should.

I need to get the multimeter out and back probe the BPP switch in both positions. The diagram shows BPP normally grounded, then 12V when closed (pedal pressed?). But that doesn't make sense in my head.

I currently have the clutch pedal position (CPP) switch wired in parallel to the BPP as that's how I thought it should be based on the diagrams. But of course it's not working.

There is an underlying assumption here that the CPP switch is working for all three switches (it clearly does work for the starting circuit). The CPP switch came from a donor Mazda B series that I got the pedal assembly from -- it's possible one of the three internal switches is bad.

 

[allmyEXes]

Yeah, that CPP could be bad, it has 6 electrical contacts on it.
RockAuto Mazda B4000 CPP

 

[97Sandbox]

Got the multimeter out. The RD/LG wire at the BPP is normally 0V, then 12V with pedal pressed.

The RD/LG wire at the CPP follows whatever is happening at the BPP. The TN/LB wire will read 0V when no pedals are pressed, 12V when brake is pressed, then 0V if clutch is pressed at same time as brake. So that switch is normally closed.

This all agrees with the Speed Control wiring diagram and demonstrates both switches are working. However, I'm still confused as to how opening the circuit at the CPP is supposed to kill cruise when 12V from the BPP is what shuts it off. It seems the TN/LB wire needs to receive 12V to kill cruise. It gets 12V at the splice when BPP is closed. But if there's 0V at the CPP without brake pressed, how would opening a circuit do anything?

In the case of my Mounty, it doesn't do anything (to shut off cruise that is), which at least makes sense electrically. I guess the real question is: is there something else going on in the factory manual harness that isn't reflected in the wiring diagram?

Could cruise be cancelled by "anything but ground?" I'm imagining if the splice were located and removed, the TN/LB wire would run from the CC servo to the CPP and would be connected to the RD/LG wire when the clutch isn't pressed. The RD/LG wire would run to BPP and be normally grounded. One series circuit. So if the CC servo is grounded, all would run like normal. Give it 12V and it knows brake was pressed, cancel cruise. Open the circuit (no longer grounded) and it knows clutch was pressed, cancel cruise. But would/could it actually be set up that way?

 

[Josh P]

Got the multimeter out. The RD/LG wire at the BPP is normally 0V, then 12V with pedal pressed.

The RD/LG wire at the CPP follows whatever is happening at the BPP. The TN/LB wire will read 0V when no pedals are pressed, 12V when brake is pressed, then 0V if clutch is pressed at same time as brake. So that switch is normally closed.

This all agrees with the Speed Control wiring diagram and demonstrates both switches are working. However, I'm still confused as to how opening the circuit at the CPP is supposed to kill cruise when 12V from the BPP is what shuts it off. It seems the TN/LB wire needs to receive 12V to kill cruise. It gets 12V at the splice when BPP is closed. But if there's 0V at the CPP without brake pressed, how would opening a circuit do anything?

In the case of my Mounty, it doesn't do anything (to shut off cruise that is), which at least makes sense electrically. I guess the real question is: is there something else going on in the factory manual harness that isn't reflected in the wiring diagram?

Could cruise be cancelled by "anything but ground?" I'm imagining if the splice were located and removed, the TN/LB wire would run from the CC servo to the CPP and would be connected to the RD/LG wire when the clutch isn't pressed. The RD/LG wire would run to BPP and be normally grounded. One series circuit. So if the CC servo is grounded, all would run like normal. Give it 12V and it knows brake was pressed, cancel cruise. Open the circuit (no longer grounded) and it knows clutch was pressed, cancel cruise. But would/could it actually be set up that way?

One way to get a 12v power source to ground something is with a relay.

 

[97Sandbox]

True, that's how I have the 4x4 lights set up.

I'd like to do some more digging into how the factory manual setup works by way of my Sport. It needs a new battery though -- I'm going to get one today.

 

[97Sandbox]

Taking a brief detour from the CPP switch, I wanted to highlight the need to rework the connector that goes to the rear integrated control panel when the full console is deleted.

If you want rear speakers, you have to loop the appropriate wires. You can also reroute the wires from the former 12V jack to the cig lighter and the illumination wires can go to the ash tray bulb.

I've seen the rear speaker issue mentioned before, but haven't seen anyone post the solution. I'll be soldering, but crimp butt connectors would be fine for this.

 

[CDW6212R]

I was one that looped the speaker wires when removing the console, in 2006. I did that first for my 99 truck made to deliver mail, a console has never been put back into it. I didn't do that with my last 98's, I don't think they needed that for some unknown reason.

For your clutch and the cruise circuit issue, I'd finish being sure the wiring is all safe and secure. Then if the CC is shutting off at the wrong time, add a relay to isolate that from the BOO circuit, or to trigger it properly as you need it to. Adding one relay is fast and easy, just four simple wires.

 

[97Sandbox]

Ah that makes sense. I figured it had to have been documented somewhere but it's been ages since I read your 93/99 thread.

I didn't get a chance to buy a battery for my Sport today, but I should be able to tomorrow. At this point, I can't find anything in the Mounty wiring that differs from what the wiring diagrams say it should be. I just want to check the BPP and CPP operation in my Sport to make sure the real factory manual setup is what the books says.

Since a 12V input from the BPP kills cruise, I don't think a relay will be needed if I get to the point of "just making the CPP work." Pretty sure I could repin the cruise output from pin 3 to pin 1 and put any hot in run to pin 2 then the CPP would send 12V to the cruise servo when the clutch is pressed to kill it just like the BPP.

It looks like the 1 to 2 switch is normally open rather than normally closed.

 

[410Fortune]

I have no console and I did not loop
Anything? Speakers work… first I’ve heard of this!!