Take pics, or even better, video.

Headlights on full bright, battery disconnected? Sure, I want to see that.

 

I was so burned out from lack of sleep while posting to Runningaford but it was fun.

Very interesting, twigsV10.

First, I've not been interested in automotive sound systems because I prefer to drive without any distractions watching everything around me, being aware of how he vehicle is operating and observing the natural scenery which is why I love being out on the road. So, It didn't occur to me to check this system but I do know how crazy they get. I know a bit about recording studio engineering and mastering with enough high quality components to build a home recording studio and a studio is where the purest and clearest audio systems exist.

The little wire: I went out and looked more closely today. It has a 25 Amp cartridge fuse (Buss fuse) in the line. It is a white wire maybe 16 ga. It goes down under the heater core toward the frame, well attached to something yet unknown and what appears to be the same wire comes back up in the same place, then across the firewall, down and through the firewall near the emergency brake pedal lever, up into the dash where it is connected to 3 wires with those flat blue wire crimp connectors that open up on the side (forget what they're called- not fully awake yet).

One of those connections is to the brake light switch at the top of the brake lever. The other two go over the column to "unknown" until I get in there further. I am thinking "Electric Brake Controller" because of the connection to the brake light switch but I have to confirm that because the wires at the back of my E-Brake controller don't match the colors of those two wires and it doesn't seem like they are attached to the e-brake controller harness even though that is most logical. I'll get under there and confirm that later

Meanwhile, going back to the other end of the wire, WHAT IN THE HECK is down under the heater core where that wire is attached and comes back up again?

Yesterday, before reading your post I was thinking "Exhaust Gas Temperature Sensor" (thermo-couple or whatever) and "back to the Banks Pyrometer gauge" This truck apparently has the the entire Banks Power Pack system, of that time; large air cleaner, larger exhaust 'Y' and pipe, EGT gauge and whatever else came with it. This will be a primo cool truck when it's done!

EGT wire? Maybe, but:

1) I can't see that wire crossing over to the exhaust system from my view from above. It Seems to go down toward the frame.

2) I've been under the truck several times looking for that EGT sensor in the exh. manifold and pipe and the wiring to it because I want to fix it but I could not see either. I am sure it is there in a more obscure location where I just can't see it from below. I did not notice that suspicious white wire and had it been to the EGT sender I would have seen it. I didn't notice anything on the frame or notice that white wire although I was not looking for the wire.

3) Looking at a basic diagram (not a schematic) for later model years (1990s) 7.3s, the Banks Pyrometer system is not wired like that. 2 wires from the sensor directly to the back of the Pyrometer gauge and above those 2 connections, a 2 wire plug that may be for the gauge light but it doesn't show where that is supposed to go. The two pyrometer wires are stiff single strand wire and those should be continuous to the sensor on the exhaust.

It's usually difficult for me to get under and back out from under the truck due to chronic pain issues, some days are better than others and that is also the case with some of the work I do on it so all of these things take much more time than normal.

So, I'm sorry it's taking so long to troubleshoot this strange electrical occurrence. I certainly did not intend to make a puzzle game out of this.

When I started this topic this is what I expected: Someone would reply; "Oh that's simple!" "It's this wire connected to that gizmo." And then I would would announce, "How could I have been such a stupid idiot not to see that!" An intelligent and educated person should be the first to know and understand how stupid they really are! Which only goes to show that it's all relative. The least can be the most and the most can be the least. I have a little speech that explains all of that much better. I'm too tired and it's way off topic so you won't have to read it

twigsV10, thank you for your helpful reply!

I was raised in your State, Eastern half- CR, and I know the state pretty well. I've probably driven by your location, looks like central or western.

I got out of there as an adventurous teenager because excitement and adventure were calling and I thought I hated that place as a teenager. I'll never forget walking barefoot on trails through the hardwood forests and along creeks where I spent most of my time as a kid, exploring and catching various critters to take home as pets. A very rich experience and much different than conifer forests.

As an adult decades later I was driving East through Iowa near Des Moines on Interstate 80 in the late winter on a bright sunny day with melting snow on the ground. With large patches of pitch black deep rich agricultural soil appearing through the gleaming white snow in stark contrast, I thought to myself, "People from starving regions in the world would think that this is heaven." Some would probably cry tears right into the ground.

That's when I knew to appreciate Iowa. I wish I could have taken pictures of that scenery on that day. It's just a memory now but others will find it.

 

I thought of that the first time it happened and checked the 5 year old battery and tray on the driver's side, all around and under the battery, even for just a thin spot in the case. Not so much checking the brand new battery on the passenger side because it had only been in there for 3-4 weeks. I put that battery in on the day I bought the truck before I drove it 60 miles to home and the vehicle had only been driven 2 or 3 times locally before I had it down for repairs and replacement of the standard stuff on a 28 year old truck that had also been sitting for a year or two. I did check the tray around the new battery and when it is disconnected again I will look on the bottom.

 

I AGREE TOTALLY! I realized that yesterday and I am going to be very very careful documenting every slight change that I make because I want to duplicate this and get it on film! Good thing I've been slow to diagnose the problem and fix it.

With that accurate record of every little thing I do when I finally do locate the probable cause I should be able to duplicate the condition and get it on film!

This will delay much of the work I had planned on doing but it will be worth it. I can find other things, non electrical to work on. Hopefully it won't take long now because I need to get my trailer harness wiring fixed at the old plugs in back a single new connector and move my 3500# utility trailer with electric brakes (nice one) into town where I can get that ready for towing.

Oh yeah, pics and diagram of "known" and relevant existing wiring too. Lots of wires on that start solenoid with faded colors so I want to make sure I have the colors and tracers right before I post a diagram.

 

Hi Phy,

(Something to consider at the end of my comment*)

I know what you mean, they are standard top post batteries. I also picked up the older battery (Driver's side) to inspect the underside and the tray looking for a missing link ( path to ground) but it was fine. The other battery was brand new and so it wasn't suspect.

The driver's side has is a 5 year old lead-acid Deep Cycle Marine Battery that came out of a boat, labelled 875 Marine Cranking Amps and 125 Amp Hours. It's also labelled 'Starting, Trolling, Deep Cycle, RV'

The New battery is rated 1000 cranking amps at 32 deg. F (5.7 C) and 850 cranking amps at 0 deg F (-17.8 C) and it replaced a junk battery of some sort. I could not afford to replace both batteries. It is the best battery that I could find at local parts stores. I examined the slight differences in the cases to figure out who the original manufacturers were of these private labeled batteries. NAPA and AUTOZONE were the same. O'Reilly Auto Parts (aka; Kragen, Schucks, etc.) was from the manufacturer who I believed to be superior to the other so I bought that one. About $150.00 + taxation without representation (an often claimed cause for the Revolutionary War... Or was it really "Screw England, We can take ALL of this for ourselves!"

Jeez, so much for tid-bit of Am. History from outside the [box].

Both batteries were tested after sitting for several days to a week, then disconnected and tested with a volt meter. Each read 12.43 volts and each with correct polarity.

*For the record, my positive cable is a mess that someone hodgepodged together. It has junk cable ends attached, etc. I remedied/fixed it as best I could, no loose strands and I bought a nice new positive one-piece cable, batteries ++ and down to starter. I got the old one removed all the way to the starter solenoid and for some stupid reason I thought I couldn't get the wires off. It was the starter ground wire which doesn't need to come off anyway, DUH! So I reinstalled the the junk cable and set the new cable installation aside.

 

There is no starter ground wire. The starter grounds via its mounting.

 

With one terminal connected on the battery they will put out exactly zero volts regardless if they're hooked up in parallel or series regardless of which terminal you disconnect.

 

Iowa is where I've lived my whole 32 years and don't have any plans on moving, I farm just west of Des Moines Iowa and feed cattle with my Dad (50/50 partnership) and that black dirt is indeed beautiful!

I am not all that savvy on the custom sound systems but I have friends of friends that have some crazy setups and most have ridiculously wired components. I'm rather curious as to what you find as I've seen some rather interesting things.

As far as the pyrometer it wouldn't surprise me if the sender was never actually installed... I know of a few trucks that everything else was installed including the gauge but the sender wasn't a big enough priority to ever get to installing.

 

OOPS, thanks for that clarification.

[Last lines from the end of this post]: I'll dig into this electrical mystery tomorrow so it can finally be resolved. I think all of the possibilities have been presented except; Residual Lightning or power steering fluid soaked hood insulation material, left to age had formed a capacitor... or a few other things- Gotta stop somewhere and just nail it so this thread will go away! I have to do that. Sorry I've been so slow.]

I was thinking of the small wire on the starter motor solenoid (goes into the starter) while at the same time envisioning the ground wire from the ground terminal on the 'start' solenoid on the fender well which goes toward the starter. but I recall now it attaches to the block. I was doing that cable thing 5 months ago. I used to know how all of that stuff worked, capicitor starts, solenoids- completely rebuilding/rewinding electric motors and generators even. Like much knowledge if you don't use it you lose it.

I haven't replaced a starter since 2004 in my Dakota

I always try to be very careful and accurate with whatever I type online so I won't mislead someone with incorrect information but I was in a rush and honestly quite burned out from a 24 hr. run of insomnia with very little sleep this morning (abt 3-1/2 hrs). I should have known better than to try to get by with that post. Looks like I'm headed that way again so I am seriously going to put the brakes on so I can have a good day tomorrow.

I should just say, "yeah that was stupid of me" and move on but I'm writing in autopilot mode....

STOP sign: SHUT UP and go to sleep!

OK.

 

exhaust temp sensor on the banks turbo system is mounted in the turbo pedestal about 3-4 inches under the turbo facing the cab firewall.

 

You are correct, I went out to the laboratory to put my suggestion to work using a 12v light. The light did not work . Aint that something ! What was I thinking? I learn something every day, now I just have to remember to remember it all, lol.

 

I'm really tired- been up all night again- Loved the post about the dogs and WILL reply to that (got it partly written on the side, but can't get to it yet).

Electricity can be confusing like that. When you wrote in your post that each battery was it's own enclosed system (something to that effect) that was the key. With only one wire To close a circuit the circuit would have to connect to the other terminal of that same 'enclosed energy source' battery, not a terminal on a different 'enclosed energy source' battery. I hope I didn't make that more confusing.

I had to draw it out to check it because this is the first rig I have had with two batteries connected in parallel.

If you don't work with electrical stuff on a regular basis it's easy to get confused (or forget), part of that is because of some arbitrary nomenclature they established long ago as a basis from which to work from which is confusing itself because it can be perceived to be the opposite - I don't want to get into that - too tired to think. (up all night again).

I've been calling the start RELAY on the fender well a SOLENOID for example. DUH. Same principle but provide different functions. When someone starts out calling the relay a solenoid it's easy to just follow up by calling it the same without thinking which is what I did and the confusion about that part goes way back. "Jump the solenoid to start it" OK, so you jump the RELAY which then energizes the starter solenoid which kicks out the starter gear and makes contacts to spin the starter motor, so you in effect jumped all of those things throught the REALAY magnetic switch...
I went on try to explain the magnetic fields in the coils and what that does... right thumb rule .... and then I thought, "What in the heck am I doing?". I'm too tired to be writing all that so I deleted it and I'm not even sure if what I wrote above is correct and I'm not going to check and see.

I will laugh if modpogue posts something similar to "There is no ground wire..." Seriously, that will be funny if I screwed something else up.

That will serve to help teach me not to write when I am too tired, which I haven't learned but some day I might.

Anyhow;
I have to go back and edit every post where I called the Relay a Solenoid and correct that so I don't contribute more to that confusion.

I traced that mystery wire yesterday and it's not very exiting but I have to post now on what that is, so I can then get a couple of hours of sleep before a return phone call comes in that I have to take. Being so tired I don't want to deal with it now so I will let the machine handle it.

 

The mystery wire that goes from the + side of the RELAY on the fender well, (start relay or starter relay) (NOT a Solenoid which I had mistakenly called it a few times):

From the relay though a 25 AMP in-line cartridge fuse (a buss fuse inside the connector with a spring loaded contact) I've always called them cartridge fuses as are the three big main fuses at the top of a service entry into a home

Then down under the heater core toward the frame, back out, across the firewall down and through the firewall and connected to 3 wires one of which goes to the brake light switch - the others suspected to be to the brake control harness (makes sense) but not confirmed. But what the heck does it go to under the heater core?

I got under the truck, those wires are in a channel along the passenger bottom of the cab and go back to the back of the cab and up through a hole.

So yup I looked in the back of the cab to find the hole and the wirez to see where they were going,

I pulled the back seat up (It's a super cab) and, No wires, noting under the seat but that which is supposed to be there. A Floor.

So I took the back of the seat off. No wires, just the interior panel and the space behind it which is mostly filled with air to the inside surface of the steel cab.

So what's in there? I couldn't find out because my right wrist got so injured yesterday and was in so much pain I could not take the panels off, but I suspect that there is wires and air in there. Probably not an NSA tracking bugger thing because why would they put it in there?

BUT, outside of the truck at the top of the cab in the center is a brake light. Maybe the wires go there, I thought. Then a wire comes back the same way out from under the heater core and across and under the dash it connects to the brake light switch (which makes sense) and the other two wire ends that it is connected to go over the steering column and My guess would be that they connect to the electric brake controller, which if working I can confirm by manually activating the brake controller and see if the outside brake light on the top of the cab comes on (makes sense) and then I don't have to dig under the dash to confirm this.

No amp or capacitor was found YET because that is all I did yesterday due to my write hand wanting me to go to the ER, but instead I went to the pharmacy and it is doing much better today but not good enough to use tools.

THAT Brake light should be wired within a harness and connected to the brake light switch without the use of this crazy wire and I am going to take it out of there and do it right if my theory is correct and confirmed from the schematics in the service manuals.

Unfortunately I noticed yesterday that there are some fasteners missing from the under side of the dashboard on the Passenger side which means someone might have removed them (looks like they are all missing on that side)

Naturally I wonder why and not too happy about it, but maybe there is something in there that needs to be fixed anyway.....

I WILL solve this mystery!

NO, I did not make a mistake, the phenomena really did happen. The second time it was bright and sunny outside, everything was as clear as could be.

When I saw the WTS light on a said "WHAT IN THE F IS GOING ON WITH THIS???? I was afraid I would burn out my brand new glow plugs!

The hood was partially open and I looked in and BOTH NEGATIVE CABLES WERE 100% DISCONNECTED AND OFF TO THE SIDES NOT TOUCHING ANYTHING METAL because that is the way I placed them.

I went to the cab, reached in and pulled the headlight switch on and THE HEADLIGHTS CAME ON! I could see the reflection on my vehicle parked in front of the truck (a stupid black Honda Civic) I walked around to the front of the truck and THEY WERE ON FULL BRIGHTNESS! (I don't mean that the high beams are on, just that the headlights were on bright as with full battery current. I turned them off and I was baffled of course, I looked at everything just as I had done the first time.

That is when I started calling friends and asking what in the world could cause this?!

I began writing the situation to post here a FTE and finally a few weeks later I did but probably a few days sooner than I should have- as per convenience, but I was sitting here at the computer and decided to do it.

So yes, the only reason in the world we know that would allow for this to occur is another power source. That is the simplicity of it in the real world.

and that's the way it is unless I have some kind of a spook battery

Thank you all for your attention.

It did happen as I said or I would not be here doing this.

Hey, I GOT AN IDEA!!!!

IT'S A MAGIC TRUCK!!!!

 

Does the truck have a tonneau cover or topper? Maybe it's actually a giant solar panel in disguise.....

Did you look inside the cab, where the heater core mounts, to see if the wire from under the hood comes through there? Sounds like some, er, enterprising previous owner might have used the heater core/hose openings in the firewall as a pass-through for some aftermarket wiring. Gotta take out the glove box and some other goodies over on that side to gain visual/tactile access.

 

Serious thought here, Are you under any electrical transmission/distribution lines, the big ones that have 500k volts, or more? Perhaps very close proximity to a microwave tower?

Back in the day of doing electrical contracting, I worked on an office building directly under those large transmission lines; the lights never went out.... no power, no problem, the lights stayed on. Scariest place I've been, and I couldn't imagine working their day in, day out for years.

Microwave towers are capable of doing similar with the amount of energy produced.

None of it will fry you, or your rig, it'd be just minute induced voltage; which you only need three things for that, a conductor, a magnetic field, and relative motion.

LMAO, I feel like it's an episode of mythbusters