Yesterday when i started my car the park, reverse, neutral and drive were all lit up on the dash as if i was in all four at the same time. the truck wouldnt allow me to go over 20mph. whats wrong?

The best way is to take your time...,Set Emerg brake,start vehicle and put into neutral..Engage 4 wheel drive,look at your dash gauge area for 4 wheel drive light to come on..Put truck in reverse and release park brake..,Back up 10ft.slowly..Then put it in drive and pull up 10 ft.slowly then you should be in four wheel drive..

1st I would check the battery, take to a auto parts store the should load check it for free. Check also the alternator depending on the state you live this may also be free. This is likely a electrical problem could be in the key sw. but not limited to the neutral safety switch where the ground is lost when shifted from neutral to park which would cause the engine to stop running (die).

sound like faulty safety neutral reverse back up switch on transmission.

Might want to check for any codes first and then while vehicle is running, check for any vacuum leaks.

Sounds like they found the problem, but I wonder about reversing the wires. They might have done that to make a generic relay work if they could not find the correct part.
Sometimes motor home builders use parts from other suppliers than the OEM folks. I doubt you can do much to insure trouble-free travel other than contact Four Winds and see if they can get you the correct relay for a spare.

on the cable there is a release on the cable lift up the lock put trans in park and the shifter in park then lock it into place

This generation of Buick seems to have a faulty speedo cluster illumination circuit.
I have an '01 and an '02 and they both have the same problem with the dash illumination.
I use the 'FEEL' sollution ;
When you start the car you can assume it is in PARK.
the next spot down with the shifter is REVERSE.

Next is going to be NEUTRAL.

And then DRIVE.

So, from PARK , 3 possitions down on the shifter is going to give you DRIVE.

The alternative is to replace the instriment cluster on you car.

Yes. Check your body grounds also and make sure they are clean and tight.

assuming you have checked the trans oil and it is full, it sounds like you need to take it to a good trans shop and have it looked at. it could be something simple or something major and expensive

Ok the knock is your flex discs on the drive shaft are bad along with the carrier bearing. Replace before you get stranded or it comes loose.
Fuel distributor may need work if it is hard to start when warm, Replace OVP relay by battery also, its always an issue.