A Mechanic reports he was shown a 14th stage bleed line that was found not connected; after he had performed Maintenance and Inspection on a CRJ-900 aircraft on a Field trip; at a downline station in 30-knot winds; driving rain; with inadequate ladders and equipment to prepare the CRJ for a Ferry flight back to their Maintenance Base.

Narrative

I was sent on a road trip from ZZZ to ZZZ1 for a left engine cowl anti-ice valve that the outstation Technician in ZZZ1 replaced the night prior. After arriving in ZZZ1; I noticed that the Captain had also wrote up Circuit Breaker CBP4 B-5 (Left-hand Thrust Reverser (TR) stow) had popped. I looked at the left engine cowling and noticed a burnt mark at the 6 o'clock position from the outside. I removed the cowl and discovered additional wiring conduit melted from too much heat close to the thrust reverser stow switch and Forward (FWD) of that harness; another harness also damaged. Maintenance Coordinator directed me to defer the TR. I then verified that the wiring damage would not present a safety issue by confirming with the Wiring Diagram Manual (WDM) and assistance from a Bombardier (Challenger) Representative on site for XXX Aviation. I then secured the damaged wiring harness and looked for further damage.I asked for a hangar; but one was not available. I did not have the proper work stands to perform a proper Detail Visual Inspection (DVI) in the 30-knot gusts; improper ladder; rain and other elements. The outstation Technician said he did not notice the damage I found when he replaced the valve after midnight; the night prior; but he did find a chaffed wire that he repaired. After deferring the left Thrust Reverser (TR); I performed an Operational check of the CAIV and it was normal. I also went above and beyond and verified that both engine cowl and wing anti-ice systems checked good. (There was enough air to drive all systems to operate normal.) I did verify that the aircraft was safe for one Ferry flight. After the aircraft flew to ZZZ and was inside; Maintenance found a 14th stage line not secure. In the past 10 years; I have never seen this line disconnected. Someone had to disconnect it as it does not just come undone. I secured the line per the AMM. Important to find out who and why someone would remove this line and for what purpose; and have them put it back together. I have a call into the G.E. Engineer for our Airline to find out when this line was disconnected; as I'm sure the engine must have had a Delta-T shift after being disconnected.