According to service people my wiring chewed by rodent is it possible

I would look for a bad wire. A sitting vehicle is a natural place for all sorts of rodents to move in and chew on things you don't want chewed on.

Yes, I would imagine that your contacts are corroded or that a rodent has chewed through your wires. Check these carefully. When you turn the key, does any battery operated feature work? Headlamps or gauge panel?

If the dash has to come out then it has to come out.

Will need to completely drain and flush fuel system and tank for starters. May even need new fuel pump. Possible mice/rats/rodents have chewed through wiring. Need to get some oil on cylinder walls where it sat for those eight years.What does it do when trying to crank it now ?

Perhaps the rodent chewed on a wire the repairman missed.

Maybe a loose wire or possibly a rodent chewed through one of the wires. Check to make certain all leads are free of debris and connected and no bare wires are rubbing against each other.

It is very hard to say without performing a visual inspection, a function test, and/or scanning your transfer case controller for possible fault codes (If the "Service 4 Wheel Drive" light is on, I guarantee there will be fault codes). It could be anything from a stuck front axle actuator to to a corroded transfer case shift motor, a cracked or broken vacuum hose, or wiring harnesses that have been chewed-up by rodents.

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by rats, mice, squirrels, etc...
Makes one gallon when mixed
and protects the surface of areas used for nesting.

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Again... Rataway fragrance can be used around children, pets, and service personnel.

What is Rataway Fragrance?Rataway fragrance is a spray that is very offensive to wild animals such as rats, mice, squirrels, rabbits, raccoons, dogs, cats, horses, skunks, and monkeys. Rataway fragrance is not offensive to humans.

Spray Rataway Fragrance from Rataway.com . Rataway stops rats, mice, squirrels, rabbits,etc from nesting & chewing

I have seen the damage that one squirrel has done on a Dodge van. Unfortunately all of the injector wires needed to be respliced. It happens more often than you think. I also knew of a rat that chewed through a serpentine belt on a 5.0 liter Mustang. The owner started the car and chewed the heck out of that rat. True story. What a mess he made.