Windshield wipers not working there is no fuse?

My son and I are rebuilding the truck listed above 1500. The wipers have quit working completely. We've replaced the wiper motor, and the relay. It will run without the wipers attached, but very slow, when you attach the wipers, nothing. The delay relay gets hot to the touch. Any thoughts?

I don't. But I'll pick one up tomorrow and start testing. Thanks for the diagram.

Hello,
This is an old beat-up D250 farm truck, so I don't want to do anything other than mount a 3 way switch to run the wipers on low & high. Wiper motor works when power is put to it, and I have checked for bad fuses/relays, etc. There is a plastic relay of some kind I removed from the wiper motor.
I also have my son's 1986 Lebaron Town & Country with the same issue. I have included pics of:
1) & 2) the motor from the Town & Country, where pins are, where relay(?) was removed.
3) the plastic relay(?) from the T&C's wiper motor
4) the same relay(?) from the D250 truck.

The truck's relay(?) does not have the melted resin the T & C does, but does have a small burn mark in the housing on the lower right (of the picture) corner of the resin-covered opening.

Whatever this plastic part is, the people at the parts store said it was a dealer-only part, and the dealership said it was a discontinued part. If this is a typical failure in the part, I don't want to get more from a junkyard that will likely just go bad within a short time...

Question 1 - is this an actual relay, or something other?
Question 2 - is there any harm in running a 3-way switch to operate the wipers?
Question 3 - any suggestions as to which pins to run power to in order to get the most benefit from the 3-way switch?
I would assume (dangerous, I know) that, of the 3 pins that are not grounds, one would be intermittent, one would be low, and one would be high. With a 3 way switch, bypassing the relay(?), am I right that the intermittent setting would not work as such?

Any other suggestions would also be appreciated.

I wasn't driving it when it happened, but, as it was described to me, during a rain they were in use and behaving as normal at first. They slowly started operating as if they were on intermittent, which continued until the switch had to be put on high to even get them to operate every 30 seconds or so, and they eventually, over about ten minutes, stopped working all together, and even refused to go to the park position.
We checked fuses, checked for power to the switch, power to the motor, etc. We didn't use a voltmeter, just a test light, but there was power through the whole system until it got to the motor. We bypassed the relay with a temporary hot wire to test the motor, and it operated. So, unless we missed something painfully obvious, we came to the conclusion that the relay had to be at fault. Which, as I said, can't be bought new anymore.
If we missed something, please tell us what it might be, and if our plan to bypass the relay will work. It's a great farm truck, and we don't want to have to park it when there's rain.

We couldn't run the hot wire while the motor was installed because of lack of access. We jumped a hot wire from the pin labeled P1 to the one labeled H in the diagram you put up. It operated, but we couldn't tell whether it was "high" or "low". We stopped at that point, and didn't try any other combinations. Should we have?

Also, I included an (admittedly fuzzy) pic of the relay, which is the bottom one. As far as inspecting it, the only defect we could see visually is the small burnt/melted spot at the bottom right of the resined-over opening. The other relay pictured is from my son's project, an "86 Town & Country station wagon with the same issue. It has the resin melted almost completely away.
Should we check continuity through the relay's pins?

I can find no continuity from any pin to any other pin in any combination on either the truck's or the T & C's relay. Do I assume that mean the relay itself is the issue in this case?

Do you know of, or know where I could find, listings of interchangeable years' models, or ones that wouldn't take much modification? Where it might just take modifying the mounting brackets slightly, I hope?
Any suggestions would be helpful. Thanks!

I was hoping there were websites out there that listed interchangeable parts, rather than trusting the junkyard's opinion - our local one isn't exactly run by Einstein.
But thank you very much for your time anyway.