My tach reading when key is in the on position moter not runing

The tach itself may be bad. Check with local used parts and get a used one. Should be pretty reasonable to buy the entire dash bezel. Install the entire bezel in your car or carefully remove and replace just the tach

Cam position sensor tells computer when to synchronize injector pulse. Have you checked for trouble codes?
Check injector fuse. Injectors should have constant voltage supplied when key is on.
You didn't give year and model. Injectors are pulsed when the engine computer internally grounds an injector. You may need to check injector circuit.

what part is cracked??

There is condenser shaped part attched to the starter moter this is the part which makes the starter moter to spin and when it is stuck the moter does not spin you can check it by one person sitting in the car holding the key to start position and another one hit it softly with some spanner or something The starter moter will move there is a small gear in it which requires replace ment Or the other possible reason can be the carbon brushes in the starter moter are worn out or the place where these brushes touch on armature the place is worn out that Y ou will only come to know when you will take the moter away from the engine Lastly I hope you might have checked your battery that it is giving sufficient current to the moter

The Black wire will connect to body ground, and it should be a good solid ground and if this wire is not grounded well then you might receive a primary voltage shock if you touch anything that is metal or grounded inside of the vehicle when the engine is running.

The Red wire should be connected to power when the key is in the "Run" position only, and a good place to find that source is one of the "IGN" connections at the fuse panel using a covered female spade connector. Use a test light and be certain that the connection only has power when the key is in the "Run" position, and has no power when the key is in the "Off" or "Accessory" position.

The White or Yellow wire should connect to the "LPS" connection at the fuse panel next to the LPS fuse using a covered female spade connector.

The Green wire will connect to the "-" negative side of the ignition coil or to the "Tach" or "Test" lead that runs from the negative side of the ignition coil. To locate the lead run down the wire from the negative side of the ignition coil and the lead should break off from that wire and it should have a tag on the wire that will say either "Tach" or "Test" (sometimes it is just an empty black wire connector) and that is if the lead does not come straight off from the wire connector at the ignition coil. If there is no lead you can get a wire tap connector to tap into the wire from the negative side of the ignition coil and then use a covered male spade connector to connect the Green wire from the tachometer to the wire tap connector.

Here is a diagram to help assist you and if you can not download the image right click on the image and then select "save picture as..." or "save image as..." and from your image viewer you should be able to read this diagram or print it out, and let me know if you require any further assistance.

try to hook neg tach wire to grd like to eng block power wire of tach to neg side of coil not positive side which is batt power

Do the following:1)key in the ON position:remove the 7.5 gauge fuse.Tach needle should read "0:". 2)put it back,go on the engine and unplug the green plug on the igniter -the big one,with 5 or 6 wires on it.The needle on tach reading should be zero.If not you have a short circuit on the black wire between that plug and the plug on the conbination meter.3) If the reading is zero with the plug disconnected,the black wire for the tach is short-circuited inside the igniter. I have one available.email [email protected]

This is a classic symptom of a defective driver in the tach's circuit board, it can be repaired by a authorized GM electronics repair center.

Both my temp and tach have gotten stuck like all of yours. When either does not zero out after you turn the engine off there is one thing that seem to work every time: 1) put key in ignition, 2) turn the key until you start to feel resistance and then turn it back (turn the key so that the battery is on and stop just before the engine is about to turn over.)

The temp and/or tach will slowly fall a little closer to zeroing out each time you do this.

Generally I have to repeat this half turning of the key a up to a few dozen times before the temp or tach will zero out. From what I have read this is a result of poor wiring that is common with cavaliers of the early 2000s.

you can also solder the wire to the tach wire, this way it won't come off and cause a malfunction