The Black Hole

[KurtECV]

I am not sure if that is what you are wanting to go with or not.

I am still wondering about that blue cheap splice connector that was connected to Circuit 569 at the BPP... Wonding if that had anything to do with the brake lamp not working...

 

[KurtECV]

The loss of 12 volts is somewhere in the area indicated in red....

Not sure where, but running a wire overlay is the easiest thing to do.

 

[KurtECV]

If there isn't a relay already being used for that circuit, that I can use, then I agree, adding one would work great.

Looking at the schematic, there is no relay for the brake lamps, comes right out of the BPP pin 4.

The side brake lamps work so that tells me that S212 working correctly... as of this weekend, we have battery voltage coming OUT OF C212 (into the body harness. so the problem is in the red area on post #2808

 

[CDW6212R]

The loss of 12 volts is somewhere in the area indicated in red....
View attachment 172332
Not sure where, but running a wire overlay is the easiest thing to do.

Is the voltage along there zero, or just a low voltage?

I had a problem with my old Crown Vic starting circuit, the start voltage was around 3v. The engine bay harness I had been through and taped up to match the bay(88 Mustang wiring). I could have taken it all apart, but I decided short term I'd leave it and use a relay. I found one OEM relay from a spare Lincoln, which would trigger with that low voltage. I never dug into the wiring to fix it, the relay worked and the engine started as it should with it.

 

[KurtECV]

Is the voltage along there zero, or just a low voltage?

I had a problem with my old Crown Vic starting circuit, the start voltage was around 3v. The engine bay harness I had been through and taped up to match the bay(88 Mustang wiring). I could have taken it all apart, but I decided short term I'd leave it and use a relay. I found one OEM relay from a spare Lincoln, which would trigger with that low voltage. I never dug into the wiring to fix it, the relay worked and the engine started as it should with it.

Complete loss of voltage

 

[CDW6212R]

I'm sorry to hear that, finding a broken circuit wire is no fun. The main harnesses are wrapped well and people don't realize how many wires they have in them.

Did you access the wires along the left edge of the rug, that's the easiest place to get at them?

Hopefully the break is along that rug, the section running up to C212 is buried behind the parking brake and dash.

 

[gmanpaint]

I was hesitant to post any of this because it only makes things confusing for everybody following along. But for the sake of maybe someone helping us to understand this....

The cruise does not work because, the ECM knows there is still a break in the brake circuit. It will not let it turn on, if you can't turn it off with the pedal.

The lack of power being sent to the high stop, is the cause of the cruise control issue.

Side brakes work off of fuse 9, (have always worked) and high stop works off of fuse 13. Fuse 13 is also the trigger for the trailer tow relays in Aux box #4 in the back. This tells me that there is two brake power circuits to the fuse box. Both of these leave the fuse box, and go to the S212 (splice).

Fuse 9 is connected to the GEM, but this circuit powers the side brake lights, and have always worked. The flasher also works. Somehow, the GEM realizes the break in the LG wire (fuse 13), and stops the cruise from working.

Here is the confusing part for me... Diagrams show the LG wire being spliced at S212 and changes to DG BEFORE the 212 connector. DG runs to the back and the relays. DG powers the High stop & tow relays. BUT.... we have LG going into the connector, not the DG. LG wire is the wire we repinned from 74 to 41 in the connector.

Ok, so I'm wondering if the shop worked back there when adding the PATS. Is there anything to do with the PATS in the back 1/4 panel? I know the RAP module is back there. Right now, I think I need to remove the cargo panel, and test power on the DG wire leading into and going away from the Aux box back there.

Thanks for those pics Don. I didn't even realize there was a connector there.

 

[KurtECV]

@gmanpaint pin 41 at c212 was blunt cut and wrapped.

The light Green wire from pin 41 on the I/P harness side was moved to pin 74.

The wire that had previously occupied pin 74 was blunt cut, and wrapped.

 

[gmanpaint]

Ok, I said it backwards. My bad. Lol

Just trying not to get way too detailed for confusion sakes. Mainly mine.

Not getting all my email notifications here is aggravating, and again, my apologies for not responding right away.

 

[KurtECV]

This is the body side of C212. The back probed circuit is pin 74. which has battery voltage at this time.

Pin 41 (White w/black on body side) has been blunt cut and shrink wrapped on the I/P side (LG).
Pin 75 is unchanged.
Pin 41(LG on I/P side) and 74 (Red w/green on i/p side) have been soldered and shrink wrapped.
Red w/green that Previously occupied pin 74 has been blunt cut and shrink wrapped.

All harness modifications shown here were done per Russel's instructions. Unfortunately due to how tight the I/P harness was routed and wrapped and lack of working room, i was unable to solder the connection in-line like i would have liked to; But the solder joint is solid and i have no doubts on its integrity.

 

[KurtECV]

Yeah i am trying to keep everything clear as i can as well for future reference/documentation and help from other members... pictures are worth a 1000 words right?

 

[CDW6212R]

...

Thanks for those pics Don. I didn't even realize there was a connector there.

I posted those pictures only to show how complicated some of the wiring is. I had lots of spare wires left from the old 93 truck, the cut 99 body harness, and a 98 Limited set of wires to dig the ARC out of.

The picture of wiring in my truck is the body harness, almost done/modified and ready to bolt in. The big two connectors there are the 212 connector, and the DJ connector. The odd smaller wire lines are the added ARC wiring, and added mirror wires that lead to my right(added) switch. That section below the 212 connector is what I hope you traced fully, that's up high in the dash as you know now.

I didn't know the brakes had two circuits. I wonder if the brake circuit split before the BOO switch, and why it would disable the CC on the center brake light. Obviously something is unique about those two circuit paths.

 

[gmanpaint]

I'm wondering if that blunt cut green/red is in fact the other brake wire needed for the high stop power. Hmm...

From all this digging into this issue, it seems the 2 wire brake switch is called a BOO. The 5 wire is called a BPP. There is 2 hot at all times, brown and lg/r. The lg wire is the output to the stop lamps. The r/lg is the actual BPP, or brake pedal position switch output. The black wire is ground.

With that said, the lg/r wire is a constant power wire, and is the wire we cut and left blunt. Hmm...

 

[Dono]

So its the brake petal position output that needs to work for cruise to work, correct?
I'm actually not concerned at all about you sorting out the 3rd brake light, that will be easy. You guys are awesome.

 

[gmanpaint]

Correct. When using cruise control, and when the pedal is pressed, it pauses the cruise control, you have to release the pedal, and hit resume for the Gem to bring it back to set speed. Gem won't let the cruise control to even turn on, if it recognizes a break in the circuit. Safety feature.

Going to keep digging into this for a little bit before I give up on it. If I can't figure it out, because of things out of my control, then will just run a new wire patch to a new ballast.

My head hurts, and I'm over stressed with this right now. Sorry guys, please don't be offended or anything with me. I am past my boiling point right now, and the only thing keeping me from going over the cliff, is a tree root. There just hasn't been any reward for over 2.5 years with this rig. It's been all work and money spent only. That is not my definition of a relaxing hobby. lol

 

[KurtECV]

Ok im going to run through the diagnostics for Cruise control Inop....

Within this post, all tests are done at the Speed
Control Servo/Amplified assembly unless otherwise stated.

@gmanpaint has stated following fuses are good:
I/P fuse 9-7.5A
I/P fuse 13-20A
I/P fuse 10-7.5A

Connector 171 (at speed control servo)

With ignition off for at least ten min, brake pedal released:
Tan/Light Blue= test for less than 10 ohms to ground.
-- If over 10 ohms/over-limit-> locate and repair open or high --resistance.
--If less than 10 ohms, proceed.

Black/Yellow= Brake pedal applied, test for battery voltage.
-- if less than battery voltage, locate short/open circuit.
-- if battery voltage, proceed

Ignition in RUN
Gray/Yellow= test for 12 volts
--if less than 12 volts, locate short/open circuit
--if 12 volts proceed

Orange/Light Blue= inspect Instrument cluster for cruise indicator
-- if operational, proceed.
--if not, locate short/open circuit

Black= ignition off, test for less than 10 ohms to ground
--if more than 10 ohms, locate short/open circuit
--if less than 10 ohms, proceed

Gray/black= Vehicle Speed input 3; The 4 WABS Control Module receives vehicle speed information from the 4 WABS sensors, it then sends this information to the Speed Control Servo Amplifier Assembly... I will have to look into testing that circuit, other than testing the circuit end-to-end. If you do test it end to end, you will want less than 2 ohms resistance, no continuity to ground and no battery voltage.

Dark Green/Orange, Light blue/black are the speed control switch ground, and speed control switch input respectively from the steering wheel controls. If you are intrested in testing them, we way wait for another post because there are several resistors within the switches (2200/680/120/1000ohms depending on what switch is depressed)

 

[gmanpaint]

Yep, fuse 9 & 13. You can see fuse 13 works the high stop. Fuse 9 leads to the Gem.

511 is the main brake circuit.
511 is LG wire, that becomes 569 DG wire (after the S212), for the high stop.
10 is the LG/R constant hot wire from fuse 13 to the BPP. This also runs to the cruise control. There are 2 of these wires coming off the back of the fuse
276 is the brown constant hot wire from fuse 9 to the BPP.
810 is the R/LG wire on the BPP that goes to the GEM to tell it the pedal has been pushed.

 

[KurtECV]

Cruise control diagrams

 

[gmanpaint]

Kurt.... I just did the cruise control test. It now gives 2 flashes, which says it is the BPP.

I also did a voltage test to the Tan/LB wire on the cruise module. It has voltage with brake pedal depressed.

Will test for voltage at circuit 1003 GY/Y with key on next. Then check continuity between circuit 307 BK/Y at the cruse module and master brake switch connector.

Since the test procedure is telling me there is a bad circuit at the BPP, I need to find out where and why. Testing voltage and continuity to the cruise module will hopefully tell me where the issue is.

Kurt, email me the diagrams, and I can turn them before posting so I can read them. lol

 

[KurtECV]

Circuit 10 goes from fuse 13 LG/R, to the brake pressure switch LG/R. then on to the brake pressure switch input BK/Y

Brake pedal pressure needs to be 5-10 lbs for the switch to open, and remove power from servo clutch.