On a Hino FD176 with dual headlights when I put on hi beam both lights on the passenger side go out and the tell tale hi beam on the dash doesn’t light up.
Low beam works as normal.
A while ago I changed to H4 globes and not sure if this may have contributed? Checked all connections and nothing is loose.
Not sure about power?
I assume it isn’t the globe as the low beam works fine but won’t work when I switch to hi. I’ll change the globe in the morning. It was an expensive Osram globe and hasn’t been in long at all
normally I would agree, any time a light goes out when another with a greater load is turned on it is the ground.
Just with a lot of Jap vehicles it grounds through the switch or relay if fitted. But still a good place to look if you can find where the switch ground is.
I put on hi beam both lights on the passenger side go out and the tell tale hi beam on the dash doesn’t light up.
Check the passenger high beam wire between the switch and the globe. Especially where it joins the wire from the drivers side.
Check the tell tale globe if blown and the wire back to the switch. Especially where it joins the wire from the drivers side. To me, it sounds like a break at the intersection of the three wires. (left, right and telltale)
We had trouble with our Hino GT when we first got it (secondhand), in short, turn headlights on and engine would stop. That later progressed to turn headlights on and starter motor would spin continuously.
Anyhow, from what i remember during the fault finding process, there are a multitude of relays in the dash, and i have an idea that there are separate headlight relays for each side of the vehicle.
If yours is the same, i can only suggest checking that the passenger side high beam relay is working.
Our 1991 FC144
hino has seperate relays for each side on the head lights and our original lights had rust forming on the reflectors and the rego man said get rid of them so I found a set of LED beams that drop straight into the rectangular buckets. What an impressive set of lights we have now.