Roy,
Not sure which electrical bay layout the 98 has. If it is the same as the 2000 chassis, suggest you disconnect the high beam connection on TB1-4 and determine if the 5v is present on the TB post or the wire. If on the TB post the source is between the relay installed in the mod and the post. If it is on the wire, it is between the post and the hi beam bulb.
If your high beam connection is on TB1-3 (older electrical bay layout) use the same procedure. However, on this layout TB1-4 has headlight power so check for leakage between TB1-3 and 4.
Steve