Which fuse? What part of the circuit is it feeding?

 

It's one of the two fuses in the engine compartment fuse/relay box. The box cover calls it the "ASD" fuse, which sits in the upper right hand corner of the box, closest to the firewall. I looked in the manual for where this fuse might be numbered and haven't seen it.
The main fuse box (the one on the left side of the dashboard) has numbered fuses indicated in the service manual. I've attached the only page I've found pertaining to the ASD circuit.

 

Ok, there shouldn't be anything else between the fuse, and the relay. You tried swapping the relays, and still had a draw??

With ignition off, check for power or ground on pins 85, and 86, in the relay socket.. (neither should show power, or ground.....)

 

Yes, I pulled the relay and there was still a draw when the asd fuse was pulled (which baffled me). I had tried swapping out the asd relay with ones from the junkyard wreck I've been harvesting parts from.

How do I know what numbers apply to the pins on the ignition switch bus/connection? I'll pull it today (need to unscrew the brass/copper bolt that holds the ignition buss/connection plug in place. It wouldn't surprise me if this eliminates one of the sources of the short when disconnected. (Interestingly, the ignition switch/harness assembly is used on GMC products and has 'GM' embossed on the plastic housing. They sell replacements on ebay. Getting the one off that junkyard wreck will be another story (if it is still available)).

 

Oh, I misread your post. I have the schematic that I sent you for pins 85 and 86. I'll pull the ignition plug and check. Thanks.

 

Check at the relay socket. It's easier.

 

So I did measure the draw across pins 85 and 86 in the ASD relay. Result 0.0 mA (that was with and without the ASD fuse installed).
The voltage drop across pins 87 and 30 was measured as 12.07 volts, as I expected.
I pulled the ignition switch connector and got 0.9 mA draw with the ASD fuse in.

The radio problem may be on its way to a solution: I pulled the right passenger speaker out of the door and found it to be totally blown! I hooked it up to my house stereo and no sound. Hard to imagine that all 6 speakers in that van are blown, but I will settle for two that aren't! I'll check the left door speaker next. If blown, I'll get a pair of replacements.

 

Measure voltage at pins 85 and 86 with ignition off. See what ya get.

 

Tried hooking my home stereo speaker to the right passenger door speaker wire. No sound! Will check left side. I'm wondering if all the speakers were blown and still hooked up if that would cause the system to have too much resistance. Will check resistance in blown speaker and report back.

 

Voltage across pins 85 and 86 with ignition off: 0.0 volts. That's consistent with no draw across these pins. ASD fuse was in place when measurements were made.