Fuel Sending Unit Wiring Connection to Instrument Harness and Gauge

[WAM]

Hello,

My apologies in advance, as I am seeking help on a '77 F250, and I know this site is for '67-72', but I cannot find any such forum on the '73 to '79 site.

I recently installed a new sending unit, and now I am attempting to get the gauge in the dash to work.

History: The guy who owned this before me has cut the wires coming back from the aft full tank, and he had spliced in a makeshift gauge.

I ran down the wires, and I was able to locate the area of concern where he snipped the wiring (coming from plug connection under the hood is one green, and one green/red stripe, wire). I have attached a photo.

I am trying to figure out how these two wires tie back into the wiring harness and circuit board.

I have found a couple of disconnected plugs; one plug is a yellow 3 pronged round pin with a black/green stripe wire, another is a single round pin black plug with 2 brown wires, and the one of greater interest to me is an orange 2 pronged run pin plug that comes from pin 15 in the instrument cluster plug.

I would appreciate any insight for not only the fuel gauge connection, but also for what any of these plugs may have been used for.

PS: I was just attempting to add some photos, but I am going way over the size limit. I am not sure how to get everyone the pictures.

Thank you,
William

[zgerbic]

fordification.net is the forum you are looking for. "com" is for older trucks and "net" is for newer. Fortunately the site has things like schematics for the trucks. Unfortunately it does not have an actual Q&A forum like this one does.

wiring_76master_3of9.png has the wiring for the fuel tank connections. Should be the same as the 77. The wiring diagram also has illustrations of the connectors which will help with the identification and rewiring.

I don't have a newer truck to look at or I would pass along more info or photos. Someone else on the forum might have a later model truck and can pass along photos.

[WAM]

Thank you for the direction Zgerbic!

[basketcase0302]

WAM
Hello,

My apologies in advance, as I am seeking help on a '77 F250, and I know this site is for '67-72', but I cannot find any such forum on the '73 to '79 site.

I recently installed a new sending unit, and now I am attempting to get the gauge in the dash to work.

History: The guy who owned this before me has cut the wires coming back from the aft full tank, and he had spliced in a makeshift gauge.

I ran down the wires, and I was able to locate the area of concern where he snipped the wiring (coming from plug connection under the hood is one green, and one green/red stripe, wire). I have attached a photo.

I am trying to figure out how these two wires tie back into the wiring harness and circuit board.

I have found a couple of disconnected plugs; one plug is a yellow 3 pronged round pin with a black/green stripe wire, another is a single round pin black plug with 2 brown wires, and the one of greater interest to me is an orange 2 pronged run pin plug that comes from pin 15 in the instrument cluster plug.

I would appreciate any insight for not only the fuel gauge connection, but also for what any of these plugs may have been used for.

PS: I was just attempting to add some photos, but I am going way over the size limit. I am not sure how to get everyone the pictures.

Thank you,
William

William,
First on the pics, (as they will really help) you have to shrink/downsize/resize them to the sites criteria, (I'm sorry but I can't remember what megapixel is the criteria)-then they will upload.

If memory serves me correct the 77 still uses an IPVR to get the grounding "signal" from the sending unit, (test that theory by grounding the wire coming out of the trucks harness by intermittently grounding it, (watching the gauge to see if it moves).
I'm pretty sure I saw my 76' EB tank sending unit connector, (and once again if memory serves me it is a 2 wire harness) here. I'll look for that inthe next day or two. Do you need that connector that pushes onto the sending unit?
Try Green Sales for our Ford truck wiring harness pieces and connectors, (if you can't source the wiring from a local boneyard):
http://greensalescompany.com/

[WAM]

Thank you basketcase! I am going to work on the truck again today. I will test that plug per your suggestion. I have been able to reduce a couple photos, and I have attached. Again, this orange wire/plug comes from the pin 15 on the instrument cluster plug. The green and red wire come from the sending unit on the tank, and that plug, grounding wire, etc. are all intact. Somewhere from the fuel tank travelling toward the engine bay, this green and red wire joins with the solid green wire, and joins with a plug inside the engine bay (driver side), and the last photo shows what comes out of the fire wall headed toward the instrument cluster.

[basketcase0302]

I won't be able to help you with the specific colors, (and please realize that ford both changed specific wire colors on each year as well as mid year if they ran out of a specific color). But...
This is gonna be a game changer for you! I always kept mine rolled up and in the glove box of my 71' for roadside emergencies. These laminated wiring diagrams are worth their weight in gold as far as I'm concerned.
I did not see the 76' truck diagram in their ebay store but don't discount they don't have it, (reach out to them):
https://www.ebay.com/itm/362612434516?h ... SwNphWXarb