Tachometer going crazy...! See video
Thread Starter
Obsessed
Joined: Apr 2019
Posts: 627
Likes: 394
From: Valencia, Spain
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Tachometer going crazy...! See video
Was working on my 71 today around the distributor. Had to take off the chrome housing that covers the plug wires and distributor. Put everything back together and all of the sudden I notice the tach is jumping around like crazy. Took it all apart again to check the tachometer cable to see if something got disconnected. Everything looked fine though and the connections seemed tight. With the engine running I could feel and hear the cable spinning around inside the outer cable. I suspect the cable went bad but could it be something else? If I do have to replace the cable any tips on getting to the tachometer under the dash. Looks very compact with air ducts and everything else. I don’t think I can get my hand up in there. Can I unscrew the dash panel where the speedometer and tach are to get at the connection there? Any insight, help or advice is appreciated...🙏🏻
Thread Starter
Obsessed
Joined: Apr 2019
Posts: 627
Likes: 394
From: Valencia, Spain
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2019 C3 of Year Finalist (stock)
Will check it out and take some pics... I did noticed the tach cable coming out of the distributor is fairly short. It only goes from the distributor to about the driver’s side exhaust manifold. From there another cable connects to it that goes into the firewall. Before going into the firewall there Is a proper male and female screw connection. Almost looks like an extension. The short cable going into the distributor has a brace or guide tray that goes the length of it and looks newer than the one that actually goes to the tachometer. I’ll get some pics to post so you can see what I’m talking about... Thanks for helping..👍🏻
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
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From: US-PNW
Will check it out and take some pics... I did noticed the tach cable coming out of the distributor is fairly short. It only goes from the distributor to about the driver’s side exhaust manifold. From there another cable connects to it that goes into the firewall. Before going into the firewall there Is a proper male and female screw connection. Almost looks like an extension. The short cable going into the distributor has a brace or guide tray that goes the length of it and looks newer than the one that actually goes to the tachometer. I’ll get some pics to post so you can see what I’m talking about... Thanks for helping..👍🏻
Before tearing into your dash, disconnect the tach cable at the distributor. You should be able to spin it by hand and not feel any binding. If you do feel something, disconnect the cable junction you mentined above and try it with the cable section coming from the firewall. You could test the tachometer itself by spinning the cable with a drill. I don't recall the necessary direction, so use a reversible drill. Make sure the needle isn't bouncing around when the drill is at a steady speed.
