High Beam issue - fresh install DS harness

Can only be one of three things:

1. The high beam filament in the bulb is blown.

2. The wire that goes from the the switch to the high beam in the headlight is not connected. It may be the wire is broken. More likely the wire has been put into the wrong hole in a plug between the switch & bulb. Check the high beam wire lines up across each plug. It is possible a connection is in the right place but dirty, however this is unlikely as it is new. They may have missed stripping a wire before crimping the connector on.

3. The high beam contact in the off-low-high switch is dirty, busted or missing.

Best test is to find the low & high beam wires coming out of the switch. Turn the switch to low beam & measure the low-beam wire - you should see close to 12V. Now turn the switch to high beam. If you see 12V on the high beam wire, the problem is in the wiring or bulb. If not, the problem is in the switch.

Don't put too much faith in the indicator bulb fixing the problem. The only thing with it that might affect the high beam is if it was fully shorted out. In that case, when you switched to high beam all of the lights, including the tail light would go out, & it should blow the fuse if fitted.