Aftermarket El Cheapo Tach acting Odd

[87ChevyR10]

Bought one these Equuis Tachs from O'Really a few months back. Been working fine until now. Seems the needle wants to hunt around. If the truck is sitting idling, the needle stays pretty calm; however, once I get moving, that sucker wants to dance around.

Now, the green wiring going to the tach pigtail hasn't been properly done up. I just stuck the wire in there and let it be. Last couple times I've had the air cleaner off, I've found that wire had fallen out. Same thing this last time. I used electrical tape to hold it in place this time and ever since, the tach needle is randomly erratic.

So, is this tach dying or what?

 

[Georgeb]

Bought one these Equuis Tachs from O'Really a few months back. Been working fine until now. Seems the needle wants to hunt around. If the truck is sitting idling, the needle stays pretty calm; however, once I get moving, that sucker wants to dance around.

Now, the green wiring going to the tach pigtail hasn't been properly done up. I just stuck the wire in there and let it be. Last couple times I've had the air cleaner off, I've found that wire had fallen out. Same thing this last time. I used electrical tape to hold it in place this time and ever since, the tach needle is randomly erratic.

So, is this tach dying or what?

Make he connection for the green wire correctly and see how it acts.

 

[chengny]

Also make sure the green wire that goes from the the tach to the distributor is not laying on (or even near any spark plug wires).