diff --git a/03-Architecture-Hardware/kicad b/03-Architecture-Hardware/kicad
index 61652cc..d2db77f 160000
--- a/03-Architecture-Hardware/kicad
+++ b/03-Architecture-Hardware/kicad
@@ -1 +1 @@
-Subproject commit 61652ccc3f92403e89a01f0ba88660caeaed6be3
+Subproject commit d2db77fddb14c07e406171c4d228b5f938f099ce
diff --git a/scripts/2026-09-25_v6_T17_f2_input_fuse.py b/scripts/2026-09-25_v6_T17_f2_input_fuse.py
new file mode 100644
index 0000000..32521ab
--- /dev/null
+++ b/scripts/2026-09-25_v6_T17_f2_input_fuse.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+"""v6 T17 — F2 (24 V vehicle input fuse) gets a real, orderable part.
+
+F2 carried the placeholder "TBD-2A-1812" (value "2A/63V-slow-1812"). The JLC catalogue has
+no 1812 fuse that is both 2 A time-lag and rated >= 63 V (1812 PPTCs top out at 33–36 V,
+below what the SMBJ33A on /24V_IN lets through during a load dump).
+Chosen: Littelfuse 0454002.MR — NANO2 Slo-Blo, 2 A, 125 V, 50 A breaking, 2410 body.
+LCSC C179005 (Extended, 1136 in stock on 25-Sep).
+
+Schematic: Value, Footprint (Fuse:Fuse_Littelfuse-NANO2-451_453 — same NANO2 land as the
+454 series; verify against the 0454 datasheet) and LCSC.
+Board: LCSC value + Value only. The footprint swap (1812 -> NANO2, 6.1 x 2.7 mm) is a layout
+step: in the PCB editor, right-click F2 -> Change Footprint -> Fuse:Fuse_Littelfuse-NANO2-451_453.
+
+    python3 T17.py hbox-watchdog-v6.kicad_sch hbox-watchdog-v6.kicad_pcb [--apply]
+"""
+import re, sys, shutil
+
+REF = 'F2'
+NEW = {'Value': '2A/125V-SloBlo-NANO2', 'LCSC': 'C179005',
+       'Footprint': 'Fuse:Fuse_Littelfuse-NANO2-451_453'}
+OLD_LCSC = 'TBD-2A-1812'
+
+def span(s, i):
+    d = 0; instr = False; j = i
+    while True:
+        c = s[j]
+        if c == '"' and s[j-1] != '\\': instr = not instr
+        elif not instr:
+            if c == '(': d += 1
+            elif c == ')':
+                d -= 1
+                if d == 0: return j + 1
+        j += 1
+
+def edit(s, head, props, ch, tag):
+    m = re.search(r'\n\t\t\(property "Reference" "%s"\n' % REF, s)
+    a = s.rfind('\n\t(' + head, 0, m.start()) + 1; e = span(s, a); b = s[a:e]
+    for k, v in props.items():
+        pm = re.search(r'\n\t\t\(property "%s" "([^"]*)"' % k, b)
+        if not pm: raise SystemExit(f'{tag}: {REF} has no {k} property')
+        if pm.group(1) == v: continue
+        if k == 'LCSC' and pm.group(1) not in (OLD_LCSC, ''): raise SystemExit(f'{tag}: unexpected LCSC {pm.group(1)}')
+        b = b[:pm.start()] + f'\n\t\t(property "{k}" "{v}"' + b[pm.end():]
+        ch.append(f'{tag} {REF}: {k} "{pm.group(1)}" -> "{v}"')
+    return s[:a] + b + s[e:]
+
+def main():
+    sch, pcb = sys.argv[1], sys.argv[2]; apply = '--apply' in sys.argv
+    S0 = open(sch).read(); P0 = open(pcb).read(); ch = []
+    S = edit(S0, 'symbol', NEW, ch, 'sch')
+    P = edit(P0, 'footprint', {'Value': NEW['Value'], 'LCSC': NEW['LCSC']}, ch, 'pcb')
+    for t in (S, P):
+        u = re.sub(r'"(?:[^"\\]|\\.)*"', '', t); assert u.count('(') == u.count(')')
+    print('\n'.join(ch) or 'nothing to do (already applied)')
+    if ch and apply:
+        for f, t in ((sch, S), (pcb, P)):
+            shutil.copy2(f, f + '.T17bak'); open(f, 'w').write(t)
+        print('APPLIED (backups .T17bak)')
+    elif ch:
+        print('DRY RUN — re-run with --apply')
+
+if __name__ == '__main__':
+    main()