Warning light on ,top right of instument panel,like a gearbox

For strangeness like that you need an auto electrician. The scan tool computer can tell which controller is faulty.

https://www.google.com/search?q=auto+electrician+near+me

You have a unique issue and that is unusual.

https://www.google.com/search?q=2005+Jeep+Grand+Cherokee+Limited+5.7.+No+electrical+power+to+rear+of+vehicle

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You should be able to order a manual at an auto parts store or your local bookstore. It is worth checking the library to see if they have a copy.

I have a similar problem - every once in a while all of my dash lights flash on like the car is trying to conk out/stall (I have a 2006 Jeep Grand Cherokee) - the car has no loss of power and runs fine, just all of the dashboard lights and warnings come on like its going to stall. Happens on dry days, wet days, cold days, warm days - at least 3 times a month. trouble is, because its intermittent no one can find the problem.

go to your local auto patrs store and ask them to read your computer to see you CODES on it. it many just be an O2 senors easliy replace.

You'll need an OBD I code reader or similar reader to pull the codes. You can purchase from autozone or online.

rip the gearbox out and fit a manual ,or scrap the truck because the cost of repair is greater than the resale value of this vehicle ,its worth a 1000euros if you get the right person ,4litre engine petrol ,road tax is astronomical and at 7 dollars for a gallon for fuel you can see where these gas guzzlers end up

H3
Your auto part store should get it in stock.
warning Do not touch the bulb glass with your fingers or other oily surfaces. Reduced bulb life will result.
Hope it will help
Dan

Throttle position sensor

first these are easy to do,second look on ebay a-1 auto I think sells replacement for around $100 U.S
Take door panel off,there are several bolts in reg and 2 keepers on the window glass unhook the 2 keepers unplug the motor and turn unit and bring out the bottom of the doorthe window glass does NOT have to come out. it should only take less than an hour to do.

Sounds like a "bad" earth on the dash head unit. Also check enging to chassis earths, gearbox to chassis, battery to chassis etc.