97 z28 won't crank over - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums
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post #1 of 2 (permalink) Old 05-31-2019, 10:50 PM Thread Starter
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97 z28 won't crank over

So I have a 97 z28 with a fresh motor ...started to turn over sluggish when warm ...replaced starter still did it ...replaced key switch and ignition switch got a new battery replaced battery cables and now all I'm getting is a click from the selenoid...i can start it by jumping the solenoid..but not from key ...anyone have these issues that could help
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post #2 of 2 (permalink) Old 06-01-2019, 07:47 AM
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You need to go to the following link and download the 96 service manual. It will have the starting & charging wiring diagram so you can follow along with my explaination of how starter works . My Files

The process starts when you turn the key to start. A rod in the steering column that goes to the electrical part of ignition switch, pushes switch to start position. Power flows out of elec part of ign sw and goes to 2 components.

If your car is manual trans, power goes to clutch start switch. When you push clutch pedal, switch is closed and power goes to the coil of theft deterrent rely (TDR)

If car is auto trans, power goes to transmission position switch. If gearshift in park or neutral, switch closes & power goes to TDR coil.

The 2nd place power goes to from elec part of ign sw, is the points of the TDR. So now, if everything is good in starting chain, and theft deterrent module ( TDM ) has received the correct resistance from chip in key, TDM supplies ground to coil of TDR. Magnetic field is produced that closes TDR points. On 96 & later models TDM is built into body control module (BCM)

Power is then transfered on purple wire to starter solenoid. Starter turns engine over.

That is the starting chain. A malfunction in any part of this chain will keep your engine from turning over. As normal key on procedure, security light comes on then goes off after a few seconds. If security light stays on, there is a vats security problem. This will keep starter from turning engine over.

Last edited by cocobolo95; 06-01-2019 at 07:50 AM.
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