I am considering eliminating the relay box for the tailgate. The one behind the drivers seat in my 87 4runner. I am thought about running a wire from the switch to the motor for the window. Does anybody see a problem with this modification? And what is the function of the relay box in the first place. If the power supply is protected by the fuses, isn't the relay box just one more thing that fails? So far I have replaced the window motor, installed new relays in the board, and cleaned the terminals on the switch. The window was working but then just stopped, so...

 

This post should probably be in the electrical section, but to answer your question ..Yes you could eliminate the rear power window relay, but you would have to have a good knowledge of how relays work and why they are there in the first place. There is also considerable wiring involved.
Relays are used to switch high current applications, this is a 20a circuit fed through a circuit breaker, so you would still have to have some type of relay controlling the circuit, as the switch wiring and switch are not designed to carry 20 amps. There are also position switches that control certain circuits of this relay. For example the back window limit switch detects that the window is fully closed, in order for the rear wiper to function and the rear wiper power is fed from the relay.
If you are having relay problems my advice is to find another one...unless you want a king size headache!

 

The time even if your labor is worth $1.00 / hour and the extra hardware meaning heavy Duty switch and wire of ample size and at least one relay or more.

The safety switches ?? They would all need to be wired in

Do you want the key switch in the hatch to operate ??

You would in fact need to build a whole new harness for the hatch window

It would be cheaper to buy New.

If you want to do this buy A copy of The Electrical Wiring Diagrams for your year.

You will need it.

then you could just hook things up and hope for the best.

It is your 4runner after all!!!

 

I wired my rear window motor directly to a 30 amp dual pole, dual throw switch mounted next to the steering wheel. You don't have to remove the relay box to do it either.

 

I modded this on my '87. I tapped into the a/c circuit (which I don't have anyway) for power to the dpdt temporary switch. It only operates if the fan and a/c switches are on. If I go topless next summer (hopefully my spring project) I'll disconnect so it doesn't get rolled out accidently.