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1968 plymouth roadrunner tac.

crazylarry74

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just got my 68 running after 20+ years of sitting any way the factory tac moves when I hit the key but when running not working checked all wires look test good is it bad?

IMG-4497.JPG
 

Rich B

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Probably tach runs from coil- may have polarity reversed? Coils will only work connected right which way. Yup, learned that one the hard way too.
 

Big John

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The factory tachs weren't all that good to begin with. Check the wiring to the tach (as said), but there should be a gray wire coming from a plug in the firewall to the negative post on the coil. The power comes from the fuse block.

That said, most likely the tach needs to be repaired. They do offer repops, but I always like to see the original stuff repaired and reused when possible. Someone here might have a good vendor for repairs.
 

Russ69Runner

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Those darn mice. They seem to love wire's. What is up with that. Glad you found your problem. Know that makes you happy. :thumbsup2:
 

Fred69Runner

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Im looking to add a tach to mine and think Id like to go with the original dash cluster type. Any good sources for a new repop?
 

Russ69Runner

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Think they are all coming from the same place. So Classic industries/ OER/ What use to be Herb's. Just put one in my dash cluster. Just took out the screw's for the blank plate and screwed the new one in. Called and asked what the blue cup looing thing was for on it. Have to get a light bulb to put in their. Took then a while to get it to me. Called and asked where it was. Might try Dante's mopar parts also. :thumbsup2:
 

Fred69Runner

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Thank you Russ. I assume you removed the entire instrument cluster to add the tack. Is that a big deal to remove? Thanks
 

Russ69Runner

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Their are only there Philips screws back their. Yes my cluster is out and was sent off to be refurbished. So put the tach in lot better with it out. They fixed the speedometer said it would never have worked. They cleaned it and put new number's on the millage wheel's. Tested the circuit board and cleaned all the light's. Cleaned the lens and put the new mile number's on it. Look's band new. I think you might have enough room to get one in with out pulling the cluster out.
 

Russ69Runner

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Fred69Runner. My car is all apart doing a ground up restoration. Now putting it back together. If you don't have Ac that might be a plus not having duct work in the way. Maybe some one else has done this with out pulling the dash and will give us a head's up on how it went. Russ.
 

Fred69Runner

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Russ, thanks for the reply. My problem is, I don't want to do anything that's going to take the car out of service for extended periods and how much am I going to put into it. Its not a number matching show quality car. It's a very nice head turner driver, but will never bring the$60-100k+++ that the ground up restorations bring. (Like it looks like you are doing). I just got it late March want I want to be able to jump in and go on cruise nights with the guys, but also want to get it the way I want it... so, it looks like I'm asking dumb questions, but I have my reasons. I'm trying to gather as much info as I can before winter comes and then I'll be doing more work on it.. Thanks again for the guidance!
 

Russ69Runner

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Fred I under stand. Wish this car could have been driven. But just to much wrong with it. Started in on it to fix it up and opened a can of worm's and every corner just got worst. So hence this is where I am at. No it is not going to be a show car per say. But did want a professional looking one. So enjoy the car and drive the heck out of it. What you think won't take long dose turn into more work than it seems some time's. Ask all you want and build the facts you need to repair the car. Good to have you here. Russ. :drinks:
 

Fred69Runner

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Thanks Russ, will do. I'll post updates on what I'm doing to it as I go... Drove it to the lake tonight to get s bit to eat, and the fuel gauge quit working...... Always something...
 

Russ69Runner

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Check the ground on the sending unit. That seems to be a big problem and easy fix. Will be looking forward to seeing your progress. Russ.
 

Fred69Runner

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Just put in a new fuel tank, so I know that end is good. It started acting up when I was reaching back there to replace the high beam indicator bulb. So think there is some wire issues on the cluster.
It looks like the wire bundle has been cobbled up by previous owners, so am proceeding with caution behind the cluster. Thanks for the input!! Also the temp guage is acting up... Looks like I may be pulling the cluster and checking wiring in the near future...
 

Russ69Runner

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Then you have a loose connection some where. Yes they did my cluster and checked all the connection point's. Replaced pin's on the big connector. May have to clean that big plug with contact cleaner and the connection point. Wish you luck on it and hope it is something simple. :beep:
 

Fred69Runner

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Russ, did you ever consider the Dakota Digital cluster? They seem popular... But pricy..
 

Russ69Runner

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Did look at other option's like that but figured to keep it simple. Just don't know if you change one thing would it lead to other changes. Like a snow ball effect. It cost 1300.00 to have this one recondition it look's brand new. Figured that was enough to spend and every thing fit's back like it was.
 

Fred69Runner

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Yup, I agree. Usually best to keep it original! Have a good memorial day weekend...
 
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