I got a '65 F100 from my dad a few years back and it was pretty rough. Not the major stuff but all the little things (wiring, tires, dash). My dad never did much mechanic work, so I know he didn't do any of this stuff. So my questions are: What is the stock tire size on these things? Its a 2wd and the current tires are so large it sits like a 4x4. If needed, I can post the info from the door plate, in case more info is needed. Also, does anyone have a part number or even know where I can get a fuel level sending unit. Mine is garbage and I currently have to check my fuel level with a metal yardstick. And thinking about it further, has anyone else had a problem with their guages not working? Mine only displays MPH and all the other needles stay put. Is it possibly a grounding issue or over time do these clusters just quit working? Any help would be great, I want to start getting this thing looking and running better. Thanks in advance!

 

There are several vendor who supply the sender,Dennis Carpenter,NPD,LMC to name a few, they also have the floats that fail to float anymore which make the sender not work. Going to ask a silly question,did you check the fuses? And yes a ground issue may be the culprit. ALso a nasty little thing is ther insturment voltage regulator that is behind the speedo, it steps the voltage down for the gauges, sometimes these fail taking the power awy from the gauges. Have you had the dash off ? Most of the trucks came with L78/15's but that is now like a LT235/75/15, LT meaning light truck.The best advice I ever got was to get the shop manual, great reference and step by step directions, common problems,etc.

 

Thanks for the reply! I have checked the float and it isnt taking no any fuel so I dont think it is the issue. Fuses have been checked and I cleaned all the points where the fuses contact to ensure there was a proper connection being made. I have had the dash apart once, but that was a while ago so I will have to do that this week and check everything with a voltmeter. I'm glad it could possible be a grounding issue or voltage regulator, because I was dreading the cost of having that thing rebuilt. So let's hope it is something simple. Thanks for the tire size as well, My speedo doesnt read the correct speed (though I know what speed I am doing by now) and I want to get the correct tires to fix this and make it look better. Thanks again!

 

Post a question about the insturment voltage regulator aka IVR and get some more input on what people have done checking and figuring out the dash wiring phantoms The IVR can be about $30 and so you want to be sure which thing is the first thing to check. On a side note Sapper? got the tab? just curious.

 

I have a sending unit if needed...also a float too as well as an instrument cluster voltage regulator if needed...That would definately make all of the gauges not work. It sounds as if you have the round speedo cluster...


let me know what you decide, PM for more info or post email and i can reply with specifics.

- cs65

 

Do you have the Custom Cab instrument panel - with gauges for temp, fuel, oil press, and amps - or the standard cab panel w/o oil press and amps? If you have the CC panel, fuel, temp, and (I think) oil press will all go through the Instrument Cluster Voltage Regulator (P/N B9MZ-10804-C). The alternator amp gauge does not. So if none of those gauges work, assuming the connections and grounds are all good, and the wires are all on the correct terminals, then your problem is most likely with the ICVR. If you don't have a wiring diagram, you should probably get one. The part number for the fuel tank sending unit is C1TZ-9275-K. I just bought one from Dennis Carpenter for $50. To my annoyance, it was defective and we will have to try again. If the ICVR is OK and you want to check whether the individual gauges or senders are the problem, just turn your ignition to on or acc while grounding out the wire that mounts to the sender. If the gauges go to full (fuel) or hot (temp) or 80 psi (oil) then the gauges are working and the sender has an issue. In the case of my fuel gauge, I had the sender out of the tank, hooked it up normally, and shoved the float to the "up" position to see if the gauge worked. Standard cab troubleshooting for fuel and temp gauges will be similar. Good luck.

 

Thanks for the replies everyone! I am not sure which cluster I have. I am pretty sure that I have the standard cab, but I hardly see my cluster in other trucks around here. I will definitely post a question about the IVR after I do some suggested troubleshooting. I will head out to mess with it here shortly and let you guys know. I do need to get a guide for this thing but I have downloaded some wiring diagrams for it, but that is turning out to be a nightmare. One of the previous owners liked to screw things up because a lot of the wiring is pretty f'ed up. Which could very well be why my gauges arent working. I will let you guys know what I find out later today. Thanks again for all the suggestions. I have attached a photo of my cluster so maybe someone could identify it for me.

 

Standard gauge cluster, speedo, fuel and temp gauges. I'm pretty sure there's a wiring diagram on here just don't remember where, post it and somebody will know for sure. Take the 4 screws you see around the speedo out then the 8 around the out side of the white bezel. That way you can seperate the two pieces pretty easily. I see the PO moved the key next to the wiper switch.

 

shoot a message to camperspecial65 he has the wiring schematic you'll need for your adventure.

 

Awesome, thank you! And yeah, not sure why they moved the ignition switch next to the wipers, but that's one more thing I have to redo. Thanks for all your help!

 

The IVR is indeed in common with the gauges: fuel, water temp., oil. You should have 12 volts to the IVR with the key on, but I'm not sure about the voltage leaving the IVR. The IVR is supposed to regulate the voltage and may reduce it as well. The 12 volts is fed from the ignition switch, and since yours does not look stock, it could also be the culprit. The wire from the fuel sending unit provides a ground for the fuel gauge, so you only need to check for continuity. Welcome to FTE and good luck.

Kurt

 

Welcome to FTE

Original 1965/66 F100 tire sizes w/15" wheels: 7.00-15, 7.10-15 & 7.75-15. 7.75's predominated and these were all bias ply tires. Radial tires were not offered until the mid 1970's for trucks.

No truck came with L78's.

Letter series tires were not introduced until 1969 (F100 & E100/200). The only size factory installed thru 1972 on F100's, thru 1974 on E200's was G78 x 15 / E78 x 14's on 1969/74 E100's.

L78 x 15's are too large for these trucks. In 1981, I installed a set of Remington H78 x 15 B/W's on my 1965 F100 which was comparable to the 8.00-15's used on 1965/72 Galaxie/LTD's except S/W's.
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D7TZ-9275-G (replaced C1TZ-9275-K) .. In-Cab Fuel Tank Sending Unit / Obsolete

Applications: 1961/66 F100/700 / 1967/77 F100/750.

Last MSRP: $118.33 / Dealer net cost: $71.00.

D7TZ-9275-G = 17 available NOS from Ford Dealers/obsolete parts vendors.

C1TZ-9275-K = 174 available NOS

CARPENTER NOS OBSOLETE PARTS in Concord NC has 171 = 800-476-9653.
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But...do not buy the sending unit until you check the float!

The float is made from two pieces of copper soldered together. Solder breaks down, gas seeps in, float settles to the bottom of the tank.

COAZ-9202-B .. Fuel Sending Unit Float / Available from Ford.

MSRP: $14.49 // FTE Ford Dealer Parts Dept sponsor PARTSGUYED.COM price: $10.43 / PartsGuyEd: Horizon Ford in Seattle WA

Applications: ALL 1957/79 Passenger Cars/Trucks / 1961/79 Econolines & 1966/79 Bronco's.
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B9MZ-10804-C .. ICVR - Instrument Cluster Voltage Regulator (Motorcraft GR-508) / Obsolete.

Applications: 1961/66 F100/1100 / 1961/66 C Series Tilt Cabs / 1963/66 N/NT/T500/1000 / 1966/77 Bronco // Misc 1959/66 FoMoCo Passenger Cars.

Available from autoparts stores, but make sure to take the original with you to match it up.

There are SEVEN other types used on other FoMoCo vehicles and autoparts store parts clucks may sell you the wrong one.

 

Thanks guys. I am definitely not running stock tire size, and apparently not stock rims either. The tires on there 235/85/16, which would give me a bit larger tire overall than the 235/75/15. The tires work just fine for now, but when I am due for an upgrade, I will be getting the correct size for sure.

As for the fuel sending unit/float. I am pretty confident that the unit is the culprit over the float. I have pulled the unit out and checked the float and it was fine, not even a hint of liquid inside. Now, that's not to say that everything is fine and it is just an electrical issue. I have a wiring diagram and am getting ready to head out and work on this thing.

Thanks for the parts numbers and info on the sending units/floats. I prefer to head to autozone with full knowledge of what I need, as they have tried telling me otherwise on many occasions, only to be wrong. (not saying they are all idiots by any means, just the few that I seem to talk to)

Also, I have no idea why they moved the key to where they did, but it could have something to do with the problem, I tried moving it back once but didn't have enough slack in the wires to make it that far. I don't know what the PO did to it, but they screwed a lot up.

 

1965/66 F100 2WD & 4WD were also available with 16" & 17.5" wheels.

The ignition switch failed, and/or the bezel that retains the switch to the dash had one or both of its notches snap off.

A previous owner didn't know where to get the original parts (shoulda come here and asked!), so went to an autoparts store and bought a gypo switch that included the cylinder & key and bezel.

This doesn't surprise me a bit, cuz peeps have been doing this for years. One reason why: Partspeeps at FoMoCo Dealers usually don't give a damn about older vehicles.

When peeps ask for parts, the first word oughtta their mouths is OBSOLETE (whether that's true...or not), cuz they don't wanna mess with it, so just shine peeps on.

 

Ok, can't find a voltmeter but checked with a test light and I am getting power through the regulator and to the gauges. How are these things grounded? is it a wire to inside the cab somewhere, or does the ground go into the harness and out to the engine bay?

EDIT: I think I kind of answered my own question. I grounded the test light onto the gauge cluster housing and found a hot wire and it worked, so I am thinking I don't have an issue with the cluster. Will the IVR fail and still allow power through, just not enough to run the gauges?

Additional edit: I was browsing the forum and saw the 9v technique to test gauges. I tried (with 6 AAs, 1.5v each) and neither gauge moved. I tried both wires to ensure I didn't have them backwards and nothing. Now I think my gauges are indeed fried.