I am trying to diagnose a problem with my headlights.  I'm in Canada so I
have Daytime Running Lights (DRL) on my Max.  The problem is that the DRLs
light up okay (they use a lower light setting on the high beam bulb), but
then when I turn on the headlights and the high beams the passenger light
goes out.  I have replaced the passenger side high beam bulb with a brand
new bulb, no difference.

I looked at the service manual and it suggests that the headlamp relay may
be a problem.  It refers to a RH and a LH relay ,which i assume is right
hand(passenger) and left hand(driver).

Can any tech tell me if there is a difference between the two, they have the
same numbers printed on them, but does that make them the same?

If they are the identical part, I want to swap them from side to side to see
if the problem follows the relay.

Thanks.