2004 envoy won't start after my house got struck by lightening. Coincidence?

Ckeck your cranck shaft sensor and if all fuses are good and see if you have fuel too

disconnect the shift cable and move shifter to park pull cable hard andreattach also check the switch behind the brake pedal

fuel pump bad

The thermostat on this vehicle's In-line 6 cylinder engine is on the driver's side of the engine, below & behind the alternator. You have to remove the alternator to gain access to the thermostat housing. You also need to disconnect the battery before you remove the alternator to avoid sparks and shorts.

Most directions outline removal of the alternator to gain easy access to the hose clamps, bolts and housing of the thermostat. I have located a site that after free registration, has detailed instructions on how to do this job, and the link below that describes an easier method with photos. Check out:

http://forums.trailvoy.com/showthread.php?t=54225&highlight=replace+thermostat

The thermostat is located inside the thermostat housing. To find it follow the upper radiator hose to the engine block.
Depending what size of engine you have the location is different.
The thermostat on this vehicle's (the Envoy & Trailblazer are essentially the same vehicle) In-line 6 cylinder engine is on the driver's side of the engine, below & behind the alternator.
If you have a V8 cylinder engine is in front of engine see the picture. Item 303 thermostat housing, 305 thermostat, and 304 thermostat gasket.

The security system (VATS/PassKey) is faulty.
There is an easy DIY way of bypassing the VATS system entirely, including the TDM (that goes faulty very often with the age of the car). You can find the write-up here:http://newrockies.ca

this engine calls for any major brand 5W20W (I prefer Valvoline), in very hot climates u can use 10W30W, but no heavier.

No, replacing the battery is not your problem. Must be pure coincidence..
Tape is ejecting because the deck is faulty. Either a broken belt or a broken plastic gear assembly. CD players in this model were made by SONY and are troublesome. Rather than trying to get someone to fix it, go to your local salvage yard and see what they have. They are for sale on ebay also. They are basically "throw-away" units as SONY struck a deal with GM and GM can't supply replacement parts. PLUS... there aren't too mnay shops around that fix these units.

You will have to have the dealer reset the security light to restart vehicle.Check all engine and chassie grounds because this is where the lighting would exit the vehicle.It sounds like a ground burnt through.

The thermostat on this vehicle's (the Envoy & Trailblazer are essentially the same vehicle) In-line 6 cylinder engine is on the driver's side of the engine, below & behind the alternator. It is not found in the typical location (which may be for the 8 cylinder engine), in an answer above.

Most directions outline removal of the alternator to gain easy access to the hose clamps, bolts and housing of the thermostat. I have located a site that after free registration, has detailed instructions on how to do this job, and the link below that describes an easier method with photos. Check out:

http://forums.trailvoy.com/showthread.php?t=54225&highlight=replace+thermostat