Another AC Fuse blowing issue

I've read through several posts on this issue but am still stumped.
I have a 1999 Pre-runner that I just purchased meaning I do not know the history on it. When I got it, there was no A/C fuse plugged in at all.
After I installed a 10AMP fuse. If the Blower is going in any speed when you hit the A/C button it blows the fuse. Here is what I have done.
Unplugged compressor. Verified that wire to the compressor does not have continuity to ground.
Replaced AC Switch, twice.
Replaced AC Control Module
Tested Heater Relay
Working from the below diagram I unplugged the AC Amplifier, the AC Dual Pressure switch and the Defroster Mode switch.
I tested the Blue/White wires connecting to the AC Dual Pressure switch, the Defroster mode switch and the AC switch. They all have continuity to one another. They do not have continuity to ground.
I tested all of the Black/Blue wires to the A/C switch, the Defroster Mode Switch and the AC amplifier and they all have continuity to one another, and they do not have continuity to ground.
I tested the White/Black wire from the AC switch, and it does have continuity to ground.
Testing with the AC Amplifier, the AC Dual Pressure switch and the Defroster Mode switch all unplugged and the ignition in the on position, engine not running:
Set to any fan speed it blows the fuse when the AC switch is turned on.
If I unplug the Heater Blower switch it does not blow the fuse.
If I unplug the Blower Resister, then the Blower only works when on high. It blows the fuse when on high. It does not blow the fuse on the other settings.
Since power to the blower is not fed through the AC fuse, I cannot figure out what could be wrong with the blower Circuit that could cause the AC fuse to blow. I think the reason the fuse does not blow with the Heater Blower switch unplugged is that the Yellow wire from that switch is what triggers the AC relay to send power to the AC fuse in the first place.
Any suggestions would be appreciated, just don't know where to go from here.

 

Welcome to TW…so you have unplugged the compressor and it still blows?

 

@caribe makaira

 

I's don't do relics. @Dm93 might.

 

I’m not wiring guru

but for what’s worth…..just went through “similar” issue with 98 Subaru GC8….minus the blowing fuse

only blew at speed 4
EVERY GC8 friend said blower resistor 100%
I bought/installed
No change
Turned out to be the actual speed switch on HVAC panel

unsure but hope helps somewhat
GL

 

I'd like to know this as well.

 

@HondaGM @Dm93 Yes unplugging Compressor was the first thing I did. Also unplugging the AC Amplifier unplugs the other side of the Compressor wire. Fuse still blows the minute I engage the AC switch.
@ControlCar Thanks but it blows with the resistor unplugged and I have completely replaced the AC Control Module in the Dash which includes the speed switch.

 

Dang it ^^^

 

I would disconnet the wire to the compressor clucth and run a temporary fused bypass. I would put a 5 amp fuse in the bypassed fuse holder and see if the magnetic clutch blows that fuse, then a 7.5 and then a 10. If the system does not blow the 10 amp fuse in in the car when you run the bypass and have the AC compressor clucth bypassed I would think that the amperage for the magnetic clutch is just too much.

 

@Glamisman The AC fuse blows even when the AC compressor is completely unplugged. It even blows when the AC amplifier (The device that sends power to the compressor clutch) is unplugged.

 

If that's the case it would seem to me you have pretty much narrowed it down to it being the Black/Blue wire I have highlighted below or an internal issue in J/B No 3.

Easy to test, connect a test light to battery positive, unplug your switch and A/C Amplifier, touch your light to the wire and see if it lights up. If it does you have a short on that wire or in the junction box, I'd unplug the junction box next and see if the light goes out.

 

@Dm93
I followed your test process. The light does not light up when testing the Black/Blue at the AC switch, the defroster switch or the AC amplifier.

 

I don't see how the fuse could be blowing when just pressing the A/C button with the A/C Amplifier unplugged then, that's literally all that's connected to it unless someone did some "creative" wiring.