I have a 2002 Tahoe that I thought had some fuel pump problem's. Hear I go. A few years back thought pump went out, dropped tank and replaced pump with no luck. Still no start. So I took it in to find out that the harness for the pump had a short. Also they told me my fuse panel was bad. Had them fix both, so I thought. Hear recently came across the same problem. Rig ran fine turned off and would not restart. I dropped the fuel tank to find there fix was electrical tape around the positive wire to the pump and that they had also broke the connector to the pump. They used a zip tie to hold it on. So I bought a new connector an re wired the harness. Tahoe will now start but as soon as I turn on the head lights it dies. I have checked all major grounds. I pulled the relay for the lights and same results. Hears the wierd part. While the rig is running I have lights off then disconnected the switch for the lights and it died. Volt meter in car bounces but reads 14.1 volts at every location but the dimmer fuse for the dash. It reads 7.1 to a try negative using a power probe. Any help?

I am not Tahoe savy in any regard.But IF it were me I would try doing some google searches or even youtube for problems with your year specific vehicle.I would even suggest checking out sites that are specific to your vehicle and scour the faq or read up on issue's with problems like yours.In short thought it to me clearly points to a electrical problem and by the headlights being turned on points to something grounding out the ignition.I will not say me idea is correct,but take some time to really dig into the problem by searching online as the web has tons of good and bad info that may help you out.