w126 wiring harness. Hard? Expensive?
 

I got a hook on an 88 420sel, body/paint perfect. All records included. Seller says the wiring harness needs replaced. Is this a DIY item? If so how much $ for parts? If not, how much should I expect to pay for a mech to do it? Thanks.

Uncommon at the least. My 24 year old 82 300SD has its original harness with no problems. I would personally pass on the car or buy it for parts. Someone really had to go out of their way to burn out that harness so your probably looking at more than just a harness perhaps the entire electrical system.

Replacing Harness an easy DIY, cost $150
 

If you have any mech ability at all, changing the harness is not a big job. You need to get the right harness (from Phil probably) and carefully note how the current one is connected to the Ignition system Rotor cap and the plugs. Either Bosch or Beru harnesses are good; some say that Beru is better and will last longer?? I don't agree that a less than perfect wiring harness means the whole electrical system is bad -- these "cables" do degenerate and can cause rough running problems. They should be replaced after 10 to 15 years at most. (IMHO)