1964 1/2 Mustang Convertible

[robert shreveport]

Little brother bought one, one owner, garaged it’s whole life. Fuel gauge goes down to half and stays, would that be the sending unit?

The convertible top needs replaced, torn at the back plastic window. About what range does a top and the labor run?

Speedometer moves around a lot, up and down not smoothly. Wouldn’t the cable need replaced or greased? A different greasing is the first choice, whatdoyouuse graphite?

[Stephenorf]

Originally Posted by robert shreveport

Little brother bought one, one owner, garaged it’s whole life. Fuel gauge goes down to half and stays, would that be the sending unit?

The convertible top needs replaced, torn at the back plastic window. About what range does a top and the labor run?

Speedometer moves around a lot, up and down not smoothly. Wouldn’t the cable need replaced or greased? A different greasing is the first choice, whatdoyouuse graphite?

Probably the sending unit is worn out. I've seen them really corroded after years of use.

Not sure about the top

Speedo could be from the cable, I don't think the cables on the Mustangs are serviceable. Replacement units are readily available. The plastic gear in the tranny gets chewed up sometimes and could cause/add to the inaccurate reading/wiggly needle.

Of course, the gauges could be bad on both. You can check the fuel gauge by disconnecting the wire on the sending unit and grounding it to the chassis. See if the gauge has full range of movement.

[Flathead Fever]

The 64 1/2 is a unique pony. My little sister got an original paint convertible when she was 16 back in 1977 and she still has it. If you're restoring it a "lot" of little things will be different and it's important to not change them. You will increase the value of the car keeping it as original as you can. You can hot rod it but just be sure to always keep any original parts so they can be put back on. All the original casting numbers, manufacturing date codes on parts are an important part of the car's history.

I can't help with the top. MY sister had a guy make a top for hers back in 1977 and it turned out real nice but how "authentic" it is I don't know. BY now there must be some good reproductions You can probably order a better fitting "original" top than someone will make for you. But before ordering one you need to check, is a '64 1/2 top the same as 1965, the stitching... Every time you do something you will need to check that it is correct for a '64 1/2, it's a weird Mustang. It super cool it an early production but some things are a pain like having a generator instead of an alternator. You really need to be on one of the Mustang Forums. Hopefully the door tag is still there, and you look up the build date and all the originals details.


The speedometer cable probably needs to be lubed. Undo it from the back of the speedo, pull the cable out from its housing and wipe it clean. Lube it with white grease. Some people say to use graphite, but we always used white lithium grease and it always fixed the problem. Easy job to do. At least I think it comes out the top it's been years since I did one. I worked as a mechanic for the phone company for 30-years and sometimes work vehicle repairs and my Ford repairs get a little mixed up. Some cables pull out from the top and some the bottom.

If you disconnect the wire from the sending unit, this is the variable ground for the gauge. With the wire off the gauge should read empty because it has no ground If you ground the wire directly it bypasses the sending units' resistor, and the gauge should go to full. That should tell you that the gauge and the wiring are good. If that checks out you will need to remove the sending unit and see if it does swing all the way up and down, maybe its rusty getting stuck at halfway. Hook the wire back to it and give it a ground wire from its mounting flange to ground and operate the float up and down. That will tell you is the variable resistor is working correctly. Another easy job except for draining the tank. Run the tank down as empty as possible before removing and keep drop lights, electrical cords... away while working under the car. Jack up the back of the car, use "good" jack stands along with the jack, chock the front tires since jacking the car up will eliminate it being in gear and eliminate the parking brake.

One thing you can try is to pull the fuel filler neck and hose from inside the trunk. Maybe you will be able to get an inspection mirror in there and see if that float arm is getting stuck halfway down and maybe free it up through the hole. That rubber hose might be cracked and need replacing anyway. The hoses would crack and fill the inside of the car with fuel fumes. The tops of the tanks would get rust pinholes from the trunk mat padding getting wet. So, check that out too. It its rusted through you will be replacing the tank. Rust and gas varnish inside the tank are one of the main causes of breakdowns on old cars. if you can see in the tank inspect it for rust. I've had 15 early Mustangs and have had to replace the tanks on several of them and those supposedly rust-free Southern CA cars. Some of them were nice original cars but almost all of those floor mats and trunk mats would get wet and stay that way and rust out whatever they were laying on top of no matter how well-maintained the cars were, garaged or not. Just about all the windshield gaskets split and leaked on them when they got to be around 15 years old. The windshield gaskets and floor mat padding is what rusted CA Mustang floors and gas tanks.

How to check a sending unit

https://www.youtube.com/watch?v=FTFpbTVv3OM

[rotorwrench]

Anything that was lubed at manufacture will need some attention after so many years.

[55blacktie]

A family member has a 64 1/2. He had the plastic window replaced with glass. He bought the car from my dad years ago, so it could be the entire top was replaced. If you have a choice, glass is preferred. If you need more info. regarding the window/top, send PM, and I'll look into it.

[rotorwrench]

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If the fuel sender was ever replaced, it may not have the correct spec part. Fuel system can get mucked up setting around too long.

Find a price for a replacement top that is good quality and installation will cost less. Early Mustangs have different top structures than the later ones. I hope all the stuff is still in good shape. I think that new cables are available if the old ones need replacement.

[55blacktie]

Robert, did you post on one of the Mustang forums?

[robert shreveport]

Stephenorf off thanks for your replies. Brother has had it about 4 was. and I just got back from seeing it. He’s not as mechanical as me. I believe it’s simple things. I saw the gauge bouncing around on the speedometer, wasn’t bad but I’d have to fix it. The gas gauge was barely off empty not as I reported earlier. Yes I’d probably drop the tank and replace the sender in the tank. His convertible top works well, it’s electric and does good up and down. Just the rear plastic window at the rear is torn.

[robert shreveport]

Rotowrench this car has 41,000 miles always been in a garage. All I can see was in great shape on the top.

[robert shreveport]

Thanks for the reply on the top. I’ll show my brother this forum.

[robert shreveport]

Flathead Fever Thankyou for such a good reply. I reported wrong on the gas gauge earlier. I just went and saw it. Man it’s a clean nice car. The fuel gauge was barely off empty and he said it has plenty of fuel. I’m not told from him what specifically it’s doing. But all your replies are great advice. Going to point him inthe direction of this forum so he can communicate here. Thanks

[robert shreveport]

Thanks for the reply on the top. I’ll show my brother this forum.

[rotorwrench]

41,000 isn't much but that wasn't in a garage. It's bound to have been wet a time or two. When you pull an old top off there may be some deterioration in the tack strip rails. After 62 years don't be surprised if a few things have deteriorated. The plastic back light is deteriorated or you wouldn't have asked about a top.

[robert shreveport]

Rotowrench, the car was sold to my brother from the original owner, a doctor. Who had it in the garage it’s whole life. Whether it’s been wet I don’t know. It has 41,000 now, brother has put about 400 miles on it since acquiring it. Don’t believe I mentioned a back light. Just know the back plastic rear window is torn.

[58Yeoman]

Backlight = rear window.

[55blacktie]

Easy enough to figure out, but is "back light" used by the English, like "boot," "bonnet," "drop head," and "fixed head?"

[rotorwrench]

The backlight term has been in use in the US since the horse & buggy days. The terms use is not as common today but many upholsterers still use it when referring to the rear window. All cars had open tops in the beginning.

The split glass window was an option in 67 if I remember correctly but the car may need the deeper well from the later 1967 cars for it all to fit in there. A person generally has to unzip the backlight curtain before folding the top if it has the heavier glass set up. The silicon seal between the two halves has to be renewed now and then with the two piece glass. Folding it wears the silicon seal out.

If the rear curtain can be removed from the top then it could be repaired or replaced to give an old top a little more life. I've never tried it so I can't tell you if it can be done or not. If it can't then the whole top would have to be replaced.

[frank long island]

i think the rear window can be removed mine has the glass and it was out when i got the car i think its bolted under the top boot although mine is a 66 should be the same

[55blacktie]

Plastic "rear light" should have gone away with side curtains.

[robert shreveport]

Rotowrench, my apologies on the word meaning “backlight”. Just have never heard it called that. Thank you for your reply!