Random Circuitry on Dash Harness, and other gremlins for fun

[WreckITFrank]

For reference, this is a1991, D90, 200TDI, HT from Italy. Any help is appreciated, thanks in advance.

Peeled apart the Gauges today so I could put the SHP Aluminum binnacle mount in while waiting for some gaskets. Found some minor gremlins in the wiring, and some random thing I have no idea what it's for.

Puzzle #1
Harness PRC8410 is in question. All the illumination wires were cut out of both sides of the plug for whatever reason. So what I am guessing is the illum wire (white/red) were all splices together, and connected to a larger awg red wire that had a fuse tube. Doubt that fuse is factory but maybe. Fuse holder and new illum wires circled in red. The screw down connector is how they connect to the illum wires now.OE harness and where they cut them in blue. Trying to figure where the white/red that came from vehicle side harness went. Was the fuse holder in play prior to whatever engineering took place here

Puzzle #2
On the gauge side of the harness, i found about a 2" wide piece of foam tape wrapping up a small device and secured the excess wire via ty-wraps. The grey foam tape had the worlds most stickiest adhesive, and was a mess pulling apart. Looks like there was a ground, 2x green/black, and a white/black wire attached. Both green/black came from the same harness circled in blue above. you can see the two wire at the bottom of the pic. The 3 in tape are the gauge feed wires. Im almost certain that the white/black had a female bullet on the end of it, connected to nothing. Any clue what this is?

Extra Credit Puzzle - Unused connectors.
Anyone know what options these are?

 

[chrishelakdo110]

My 110 is also Italian. Finding more wrong than right under the hood and dash. Unfortunately can’t be much help. Good luck.

 

[javelinadave]

I'm going to take a wild guess. It is/was some type of alarm system. I would recommend to clean up the wiring and switch to VDO gauges.

 

[WreckITFrank]

I'm going to take a wild guess. It is/was some type of alarm system. I would recommend to clean up the wiring and switch to VDO gauges.

I thought so too but would be surprised as PO was definitely a farmer or hunter, and the rest of thewiringisn't reallyall that bad. OnlyadditionalthingI foundwas CB wiring. But could have been before him as well. Either way the VDO setup is pretty much ready, short of the final connector. Just trying to make sure the rest is GTG. I can pretty much unplug that old binnacle harness and tuck away the plug, just need to confirm that red illumination fused setup

 

[javelinadave]

Nice work @WK2Burner. A tidy wiring job warms my heart. A birds nest gives me indigestion.
Trace the red wire, I bet it dead ends somewhere on the truck.

 

[jymmiejamz]

When I wired up the VDO gauges in my old 110 I used one of the connectors on the right front inner fender on a Disco 2. With that, I could easily disconnect the whole instrument pack with one connector.

 

[MountainD]

That circuit board looks a lot like the low fuel warning light gauge pcb. I’m traveling so didn’t check wire colors though.

 

[WreckITFrank]

That circuit board looks a lot like the low fuel warning light gauge pcb. I’m traveling so didn’t check wire colors though.

nailed it. thank you, seems as though the internets confirms.

my shooter mcgavin gif wont work so you get this instead.

 

[WreckITFrank]

Confirmed by Red on the overseas forums. Odd how terribly this module is implemented. Literally hanging there with terrible foam tape and extra wire ty-wrapped in.

Low fuel light permanently on

1991 ex military 90, 2.5nad. Low fuel light coming on intermittently, then after a few days permanently on, fuel tank is half full and fuel gauge is showing correct level.Easy fix with a new fuel sender STC1139 or so I thought !! BUT still got the same problem. Fiddled with the connections on top...

forums.lr4x4.com

 

[MountainD]

I’m planning to fiddle with one of these...eventually... https://www.spiyda.com/gauge-electronics.html

 

[WreckITFrank]

What does everyone else do? Odd this is not really discussed that often. Is this only a tdi problem?

 

[erover82]

I ran into this puzzling low-fuel indicator issue and got to the bottom of it today. The fuel level sender has three contacts - ground (black), fuel level (green black), and low fuel (white slate). It appears that early trucks utilized this "low fuel" contact to directly drive the binnacle low fuel indicator light, while later trucks omitted the use of this output from the sender altogether. Instead, they implemented that goofy circuit board which analyzes the fuel level and triggers the low fuel light by feeding the generated signal back into the harness. I'll post pics tomorrow for posterity.

The reason I ran into this issue is that I'm working with a new harness that lacks the goofy circuit board, so was left wonder how in the world I was supposed to trigger the low fuel light. It turns out you simply run a wire from the unused sender "low fuel" contact to the same contact on the harness that the circuit board feeds.

 

[erover82]

 

[mitherial]

When I wired up the VDO gauges in my old 110 I used one of the connectors on the right front inner fender on a Disco 2. With that, I could easily disconnect the whole instrument pack with one connector.

^ This is a great idea--would save so much hassle messing with the gauges and wiring.


My "Italian" Ninety came with a small cameo of a Saint mounted to the instrument binnacle--presumably to help ward off electrical gremlins. (Definitely is no longer working, maybe I should find a Catholic priest to "re-bless" it...)

 

[Houck]

View attachment 25484

Thank you!!! I have been trying to figure this same thing out. Now I can move on to the next thing on the list.