Ignition Switch works sometimes

My wipers, heat, etc. will only work part time. Do I need a new ignition switch or the harness where it attaches to the back of the switch?

Most likely it's the switch - which is on the end of the harness. The lock, where the key goes, may be okay - unless it's loose.

Can I buy just that switch or the whole harness? Thanks!

I can move the key a little bit until the heater, wipers, and the radio will come on. But with the least bump they will all go off. Is it the lock switch or the harness that's bad?

It's the electrical harness part that's bad. They go out on these as these trucks get to 2 decades old, common issue.

The key/cylinder (lock switch) part is fine.