[skidderhitter]

...and it's not the bulb (of course). After going through that completely ridiculous hassle of replacing a headlight in my '75, it's not the danged bulb (!!!). It shines very dim on both hi and low settings. I figure it's probably a bad ground, but I'm not sure where to start looking. Anybody had this problem and found the bad spot? Or am I way off on my guess? I would much rather fix it properly than splice a ground in (how tacky), this car is very original...

On a slightly different subject, my '78 has only brights, no dims. It is not either switch (already swapped that out, twice). Is there a relay somewhere that could cause this? It's probably something really simple, like a stinkin' fuse or something; but I can't figure it out. Been pulled over twice already.

 

[h4lights]

First problem is feedback through the ground circuit, sometimes caused by a blown headlight filament. Otherwise check all the grounds and clean them up.
Second problem is harder to define. If brights only and you have checked continuity of the switch in the high and low settings as well as the combo switch(those pins and connectors sometimes fuse internally), then something has fused somewhere else.
Start from the source of voltage,(input side of fuse box), to the circuit and trace forward until you find the problem.
If your automotive electrical skills are marginal, like mine, it's sometimes better to take it to a competent auto electric shop where a trace and repair utilizing the correct equipment is well worth the cost.

 

[skidderhitter]

I can wire my own stuff, but I'm not too great at fixing faulty wiring. As in, I'd be much better off rewiring the headlights (on the second Z) than trying to find the problem area. Maybe a professional is the answer... thanks for the info, I'll be working on the '75 in the beautiful NW rain this weekend (anybody got a shop with a woodstove and a fridge I can borrow??

 

[chrisp]

I just fixed a dim headlight on my 71. It turned out to be a bad conection at the fuse panel. I checked the voltage on either side of the fuse for the bad light and received a higher reading on one side. I cleaned (sandpaper) the contacts, replaced the fuse and voila, a bright headlight. Good voltage on both sides of the fuse made a difference.

Chris

 

[TurboSi]

Been working on cars for 35 years.....in my experience this problem has ALWAYS been just a bad connection on the back of the headlight. Simply unplug it and plug it back in. If you wiggle it while the light is on you should see the headlight get bright again. Clean the connections if you are ambitious.

 

[ConorP]

I agree that it's the fuse or fuse panel. Take a multimeter and check both fuses on both ends, if they are warm at all after having your lights on for a few minutes then clean the insides of the fuse holders and replace the fuses. While your in there replace all the other fuses, especially the fan fuse which runs hot anyway.

ConorP

 

[johnh240]

Just replace the fuse. Don't look at it. Don't meter it. Just replace it. Have seen several (including my own) where the fuse will have a micro crack in the fuse element that is virtually only visible with a magnifier. It will carry just enough power to dimmly light up the headlight. Headlights have power to them from battery circuit and separate fuses at the fusebox for left and right. Ground is obtained through the headlight switch. The grounds for high beam or low beam are common to both headlights. In other words, if you have a problem with just one side (left or right) check the power side of the circuit. If you have problems with high or low beam on BOTH headlights check the ground side. It is possible to have low voltage to the fuse box but if that happens you will likely have dim lights both high and low on both sides.

 

[jrljd]

Had the same problem on my 80'Z. Went through all of the steps outlined in the responses, no luck. Finally took the colum apart and checked the multi-switch that controls the headlights. Voila!!! Loose connection. Now all is well, plus have new headlights to boot.
Good Luck

Jason

 

[skidderhitter]

Well, I'm wondering, then, if the headlights each have their own fuse?? I know some cars are like that (good idea, that way if one blows you can still make it home in the dark), but are Z's? I hadn't thought so. It was not the connection on the back of the bulb, at least, it made no difference when I wiggled it and then proceeded to clean the connector. I'll try some of this stuff and see if anything works... thanks guys - skidderhitter.