Head Lights Will Not Work

[49 chevy truck]

My son-in-law has a seventies vintage truck whose head lights just quit working. He reports that he has checked all the fuses, checked the head light switch, and checked the ground to no avail. He is ready to wash his hands of it and take it to auto electric shop to be repaired. What is wrong with the lights? Any suggestions would be appreciated.

The Father-In-Law

 

[Frankc]

Check to see that the dimmer switch is working.

I am not getting older I am getting wiser.

 

[tech1]

Check the Headlight switch, dimmer switch, and the bulbs.

 

[eugene68]

I am new to this board, but I have had this happen three times to me.
once on my 69 gmc, once on my 68 chevy, and once on my 76 blazer, each time the problem turned out to be corrosion on that little isolated terminal on the front of the passenger side fenderwall. if you trace your little wire off of the + side of the battery post, it should go to this little isolated terminal which in turn your main lights work off of. I think. I know in each of my cases, I always end up taking the wires off, cleaning the post/ recrimping the ends of the wires back into good wires, and that seems to cure the problem.
I am by no means an expert, but it is the first thing I check now after fuses. Hope this helps your troubleshooting .