Electric short, now Tahoe won't start

[WillyB]

I tapped into the compass/temperature power of the rear view mirror to install a new radar detector. It seems I've shorted something. The +12V line on the mirror is now dead and the Tahoe will not start. Any ideas???


It cranks and "wants to start" but its like the plugs aren't firing and there is a strong smell of fuel.

All the fuses in the dash fuse box and under hood fuse box are good. Could I have damaged a relay? What could cause this problem?

The guy at AutoZone thinks I've triggered the theft deterrent system, but the security light does not come on and all electronics (exept the mirror) seem to still work.

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1999 Tahoe z71 5.7L v8 160K miles

 

[SunlitComet]

Diagnose the security light issue first. <y first guess is you may have fried a common ground between them:


SECURITY Indicator Inoperative

SECURITY Indicator Inoperative

SECURITY Indicator Inoperative (Part 1 Of 2)

SECURITY Indicator Inoperative (Part 2 Of 2)


CIRCUIT DESCRIPTION
The Security Indicator Inoperative check is designed to find out the reason the Security indicator is not illuminating. However, the Theft Deterrent System Diagnostic System Check must always be the starting point for all PASSLOCK system troubleshooting.

The diagnostics in this table are designed to troubleshoot non DTC troubles. For example battery power, ignition 1 input, ground, and shorted or open SECURITY indicator circuit.

DIAGNOSTIC AIDS

• Perform a visual inspection of the wiring and the connectors.
• Refer to Intermittents and Poor Connections. See: Initial Inspection and Diagnostic Overview\Intermittents and Poor Connections

TEST DESCRIPTION
The numbers below refer to the numbers in the diagnostic table.

1. This step determines if there is power available to the instrument cluster.

1. This step tests for continuity in circuit 749.

1. This step tests for a short to battery in circuit 749.

1. This step tests for an open in circuit 651.

1. This step verities it the gauges fuse randomly opened.
2. This step determines if there is a short to ground in the EVO/PASSLOCK module.

1. This step tests for voltage at the battery side of the Security indicator.

 

[carcrz]

well willyb what have you learn from this experience? just joking i thought the theft deterrent was supposed to kill the fuel pump not the spark but i might be wrong i'm thinking it may be a relay