I don't think they stop if one bulb is out.

If they were working before you cut the harness, you could have grounded out and blown the fuse. You might also check the oem wiring for burn marks from welding.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed