tach half works

[turbo buicks]

the green connector w/the 2 white wires the plugs into the black connector was unplugged in my car. it controls the tach. until i plugged it in my tach stayed pegged at redline. i plugged it in after seing it in a caspers magazine and now at idle its not at redline but it stays at around 3500 RPM. this is not the engines actual RPM though. whats the problem w/my tach? is it that relay thing in the dash (i think) that controls the boost and tach guages. i think caspers just came out w/replacements for them.

 

[Carolinaturbot6]

The green plug you're referring to, located just behind the alternator, is supposed to be unplugged unless you hook up an aftermarket tach. If you do end up buying an aftermarket tach, that is when you will use the green connector.

The black connector, located in the same area, is a fuel pump test relay.

They should not be connected together.

It's very common to have the factory tach go bad. I'm sure John Spina (Caspers) can help you on the fix.

HTH