Tach stop working

Gentlemen,

No good news today. Took my car for a drive to get her warmed up and get some gas and the tach stopped working. It's a 73 (T5)Grande Coupe, 351C, with a 4 speed. I did some reading on the TACHMAN website and still don't have any idea. The TACHMAN said that I can remove the tach and send it his company they can fix it. Anyone ever heard of this guy? Any suggestions? Thanks!!

Right on his website he say's he won't do 71-73 Mustang Tachs as there isn't any parts available.

It depends on what you want to do with your tach....I know there was an outfit that would convert it over to a 3 wire.

I also know that one of our members, Wolverine,is trying to see if he can get my spare tach working ....

http://www.rccinnovations.com/index.php?show=menu-mustang-all

This fellow converts them to modern movements and has a good reputation

http://www.rccinnovations.com/index.php?show=menu-mustang-all

This fellow converts them to modern movements and has a good reputation

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Thanks for the info Jeff, I got in the car this morning to drive to work and the tach started working! Lets just hope it keeps working.

Right on his website he say's he won't do 71-73 Mustang Tachs as there isn't any parts available.

It depends on what you want to do with your tach....I know there was an outfit that would convert it over to a 3 wire.

I also know that one of our members, Wolverine,is trying to see if he can get my spare tach working ....

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Thanks Ken, I drove the car to work this morning and it started working, go figure.

My tach has been doing the same thing since i owned the car. 6-7 years. It usually works fine but once in a while i look down and its not working so i "gently" smack my hand on top of the dash and it starts working again. LOL just waiting for it to die completely before i get another one. i checked all the wires going to it and all seem fine. i had to install the msd tach adapter to get mine to work right with my msd dizzy and box.

Who was it had the digital dash conversion with led's?

Sounds familiar... Drove home from work and it wasn't working again. I'll try smacking the dash, just not too hard.

Sounds familiar... Drove home from work and it wasn't working again. I'll try smacking the dash, just not too hard.

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Same here, smacked the dash a bunch of times and it starts working.

After driving a few months it seems to always work now. I guess some corrosion was stopping the needle.

The Tach meter movement winding is in series with the run voltage. If the movement burns open the car will not run. Most of the problems described sound like "mechanical stick" due to age and dirt. The tach repair gurus may have a special cleaner/lubricant for that purpose. I would ask a pro for a recommendation before attempting to clean the pivot points. Chuck

The Tach meter movement winding is in series with the run voltage. If the movement burns open the car will not run. Most of the problems described sound like "mechanical stick" due to age and dirt. The tach repair gurus may have a special cleaner/lubricant for that purpose. I would ask a pro for a recommendation before attempting to clean the pivot points. Chuck

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Or hit it harder!! lol

Guess what...stopped working again, maybe for good this time. Ill probably send it to the site suggested by Jeff when i get some extra cash. There are a few higher priority projects ahead of this one... unless it shuts the car down. Thanks again for the help!

I believe if you disconnect it the car will not run.

I believe if you disconnect it the car will not run.

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+1. It will not run for the reason mentioned above. You can build a jumper so the engine will run. Chuck

Since the car continued to run with the tach inoperative, the failure mode of the tach is in the needle/gauge area. The input side of the tach is a transformer that steps up the voltage and current so that the meter can react to it. If the transformer blows in the primary side (i.e. the side of the input), then the car will stop running. If the transformer fails in the secondary side, the car will continue to run.

So...either the secondary coils of the transformer blew (unlikely to be an intermittent problem) or the meter guts are acting up. I'll place my bet on the latter.

I believe if you disconnect it the car will not run.

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Rick, You are correct. The car will not run without the tach hooked up. You can use a 2 trailer wire connector to plug into the tach wire and just connect the two wires together to complete the link. Car will run fine then.

I believe if you disconnect it the car will not run.

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Rick, You are correct. The car will not run without the tach hooked up. You can use a 2 trailer wire connector to plug into the tach wire and just connect the two wires together to complete the link. Car will run fine then.

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Thanks!! It's been working just fine the last 2 times I drove the car. I will probably wait until I replace the carpet/sound deadener and heater core, I'll basically have to remove most of the interior anyway.

you can also jump it with a paper clip if needed. just reach up under the dash on the left side and you can get to the plug connector for the tach, you can with some effort disconnect the plug, pop in a paperclip and then just wrap it with electrical tape. least it will get you moving again and it shows as an official repair in my 72 shop manual.

my tach is flaky with a sticky needle so from time to time i give my lower dash a smack and it starts working again.

a few years ago nobody rebuilt the 71-73 tach and i would of needed to buy another 350$ instrument cluster just to get a tach that may or may not have worked.

Wow... a no kidding paper clip fix. Sounds like even I couldn't screw that up. Love it!! Thanks!

Wow... a no kidding paper clip fix. Sounds like even I couldn't screw that up. Love it!! Thanks!

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Just make sure you don't hit a ground.