The previous owner did two things to this '71 F-250 Camper Special that I am wanting to undo. The first is a push-button start. I am assuming that there was an issue with the ignition and the cheap and easy fix was to bypass it. The key still needs to be in and the ignition turned "on" for the pushbutton to work. There are two red wires that run into the engine compartment and connect as seen in the photo. Given this hack, what is the likely part I will need to replace in the ignition? And once that is done, can I simply pull this hack?

The second is a set of aftermarket gauges. I'd like to return to the stock gauges (unknown at this time if they are functional. Here is a pic of the back side of the gauges - they are coolant temp (not working), vacuum, oil pressure, and current/voltage. I pulled the instrument cluster and it appears all the connectors for the gauges are intact, so I'm not sure where the sending units are or how they may be hacked - though the coolant temp wire is obvious, running to the thermostat housing (still, it does not work). I'd love suggestions on how to unravel this mystery - does it have anything to do with the disconnected plugs on the firewall in the third photo?

 

Here you go:
https://www.fordification.com/tech/schematics_h.htm
https://www.fordification.com/tech/ammeter.htm

 

I'll tackle the ignition switch. Probably the switch is not working on the start circuit. Install a new one and if it starts disconnect the red wires. If it doesn't start you're going to have to trace the wires that are open and the schematic will tell you what wires to check.

 

I don’t recognize the plugs at the firewall, so I’m not sure about those. I’ll check under my hood to see if I can spot them.

I had the same issue. Some of my gauges on my 69 F250 worked, some didn’t. I didn’t trust the ones that worked, so I ran new wires thru the dash and left the original wires from the dash. (So I could restore them later.)

I ran new wires for coolant temp and oil pressure. I bought Equus gauges and am very happy with those. You will need to use the sensors that come with the gauges so they are matched. I also ran Trans fluid Temp and trans fluid pressure, because I had an overheating problem with the trans, so I wanted to keep an eye on it. Lastly, I measure voltage instead of an amps, so I’m watching almost everything.

I didn’t have enough under-dash room so I mounted my cluster around my steering column with hose clamps and bent metal brackets. My buddies laugh, but it works well, and when you’re restoring an old truck you have to know the health of it as you go along.

 

The 2 red wires in your first pick, 1 is grabbing +12V power from the battery terminal of the start solenoid and is going to the push button switch. When the button is pushed it sends power to other red wire going to the start terminal on the starter solenoid. To revert to factory you need to connect the S terminal of the solenoid to the ignition switch to the solid black wire (Ignition terminal). If you have an automatic there is a neutral safety switch in between the ignition switch and the starter solenoid which prevents you from starting in gear.
Gauges are a whole other animal. The aftermarket likely have sensors with different output voltages / resistance than what the factory gauges are calibrated for. You will need to replace the sensor (sending unit) for each gauge (oil pressure, water temp, fuel level, battery etc). The voltage regulators on those gauges commonly fail so you may need a new one. I skipped all of this and went the Dakota Digital RTX. It looks identical to stock until your turn the truck on then you have digital items light up, it looks awesome and comes with all the sensors and you can program what ranges you want so you can use any fuel sending unit

 

Ah. Yes. I would have missed that part. Ive been pulling on the rats nest of wiring that is in here and think that my time might be better spent eviscerating all the non-stock wiring and starting fresh; rewire what doesn't work. I did see the Dakota Digital stuff, and it looks intriguing. I love the stock look but appreciate modern conveniences! I am fortunate to have a decent budget for this project (at least until my wife stops just rolling her eyes and starts to openly protest) so I'll explore that route...especially if it has matching sending units, etc. I mean, if I have to gut this down to stock, I cant lost that way, yeah?

And I just realized two things - I have no gear selector indicator on my steering column, and the windshield washing stuff is completely missing. More fun! I think my baling wire throttle control needs to get priority first.

 

Nice website! I grew up in high tech, so I should be able to decipher this! Thanks a million!

 

First thing I did with my truck was replace all of the wiring. I purchased the Painless Performance kit which included the harness, and most of the switches (ignition, lights, etc), plus all of the connectors etc. I also added an accessories harness for the extra things I added like electric fans and auto on lights etc.
I am super happy with the Dakota digital gauges, I added additional modules, my steering column also does not have shift indicator so I installed the Dakota digital module and sensor to display gear position, this module also takes care of reverse lights and neutrally safety switch. Also using Dakota digital to be my fan controller which I can program each of the dual fans to turn non based on temp setting. I added the fans because I added AC and live in Phoenix and need electric fans running full blast when stopped in traffic, mechanical fan cant keep things cool at idle in the desert.
I also didn't have washer systems so I added the $25 universal one from amazon but used the factory original squirt ends because they mount hidden in the cowl. You can get those from Dennis Carpenter if yours are gone.

 

I am also in the Phoenix area. This truck has a transplanted 460 motor but I believe the wiring harness would be good no matter. Did you consider the American Autowire harness, or any others? The Dakota Digital system seems like the answer to a lot of puzzles though. How long was your rewiring project? As as for the dual fans, which accessory harness and fans did you go with? Stock radiator too? I would like to eventually put A/C back in this, but that's down the list quite a way. As is, I'm already in a lot deeper than I thought I would be after only a couple weeks. Guess I'll have to seriously consider doing a full teardown of the interior so I can get the dash working again - the air controls are all thrashed as well.

 

I believe that your plug that you show in your 3rd picture is the engine compartment wiring harness for your temp, and oil sending units. There are 3 wires in this harness, and I believe one of them goes to your coil. The previous owner probably pulled this harness out when he put in the aftermarket gauges. NPD sells a repo harness for this if you want to go back to the original wiring set up. You would more than likely need to get new oil and temp sending units from say Napa, as often the gauge clusters use different sending units than the originals. I have a 1972 F250 and this is where my harness comes thru the firewall.
https://www.npdlink.com/product/wire...%20DESCRIPTION

 

Thanks, Green - I'm pretty sure that's it, after studying both the master wiring diagram and the install instructions for the Painless Performance full wiring harness (those instructions are absolute gold for a beginner like me). I'm pretty sure I'm going to have to gut the entire wiring mess in this truck and start from scratch. It is an unbelievable mess. I dont think there is anything stock on this any more...there are so many bypasses, hacks, additions, subtractions, etc because of various camper swaps, a motor swap, and the usual "I'll fix it later" stuff. $900 for a harness seems a fair trade for my sanity.