Have a '70 pickup 521. I have posted on this forum before with pics, but been so long since I came back I had to re-register. Will throw pics back up once I get the lights back in shape.
When I searched the topic found more info on none working headlights vs. my trouble of "Over-working" headlights.
So all lights work with the exception of pass. side markers and reverse lights which need new housings so for now they are disconnected and taped up. Then one morning lost headlights all together and found I blew a fuse on fuse box....upon replacing fuse/cleaning fuse box contacts noticed when lights were on fuse got super hot really fast. Figured got a short so i started witch checking continuity on light switch. There I found out orig light switch had been replaced with $3 two position switch from a part shop. It's the basic 5 post with 15a fuse built in power post, park post, headlight post and two tail light post. Here is were I found first problem:
First owner unplugged stock headlight switch from wiring harness and connected 5post aftermarket switch with just some wires with the proper male and female wire connectors. The stock wire harness has a 6 pin harness with the headlight, tail light, power and relay pins along with two empty spots. but he connected the new after market switch with one wire from power slot to post on switch one wire connecting headlight slot to proper post on switch and one wire connecting taillight slot with proper post on switch, however, the relay slot was left empty.
after reading post by ???Daniele C??? about the 521 headlight wiring I figured the lack of the relay switch being in the circuit now is leading to the over heating, blown fuse and over heating/blown fuse of the after market switch.
Just recently I changed to a job which requires a longer so commute so I am assuming the lack of drive time before was enough to allow me to use his wire setup without a blown fuse, but now for whatever reason it's popping them.
with aftermarket switch I get continuity power to taillight post and cont. power to tail to headlight when in respective positions. Before the fuse blew I had fully working head, tail, marker, instrument, stop and high beam light. I am thinking my issue with the overheating fuses is the lack of relay in my circuit and I just need to wire it in. I am just trying to figure out how to wire it in with existing aftermarket switch or do I only have the option of buying a harnessed switch for like 80 bucks? Or is there some other option?
Any help would be appreciated sorry for the length wanted to make sure I fully explained what I have seen and done
James