Hey mates

 

This past weekend my headlights went out on the Z. I updated to an H4 conversion when I first got the car but since I'm already in there I do have a few questions. Is there any issue running a higher wattage bulb on the stock harness - without a relay?

 

Thanks
Jan

Unless you're switch contacts are immaculate, yes. You'll build up more heat in components. If the lack of light is an issue, higher wattage bulbs won't do much for you. The big issue is voltage drop. Before I installed relays in my 73, I was only getting about 9VDC at the headlight socket with the car off. That 3 volt drop equals a very significant drop in the percentage of light output. Go with relays, and you probably won't need higher wattage bulbs. It will be better for your electrical system, too.

Running headlights on a stock harness is already a problem with these old switches!  Use a relay for shure. I personally i use a separatly switch for the H4 lights... to much work a relay... Haha...

 

Your switch has burnt down contacts now..

Unless you're switch contacts are immaculate, yes. You'll build up more heat in components. If the lack of light is an issue, higher wattage bulbs won't do much for you. The big issue is voltage drop. Before I installed relays in my 73, I was only getting about 9VDC at the headlight socket with the car off. That 3 volt drop equals a very significant drop in the percentage of light output. Go with relays, and you probably won't need higher wattage bulbs. It will be better for your electrical system, too.

 

Do you happen to have a wiring diagram or pictures of how to set up the relays - I'm assuming there's going to be two.

Can you wait a couple of weeks? I just got all of the stuff together to redo the relays on my 260Z. I just need to get a work project out the door. Then I will have photos AND drawings done.

Check out Daniel Stern Lighting website

I strongly recommend the MSA / Dave Irwin harness for ease of use, but in case you choose to tackle it yourself, here's some info that I collected along my journey:

 

http://jarvas240z.blogspot.com/2014/07/headlight-wiring-harness-with-relays.html

While I highly recommend Dave's product, it is not plug and play for the 260Z/280Z. Unless the OP has extra connectors available to send Dave, he's about just as well off with a DIY setup.

Here are universal Plug and Play kits that will work on any car, including 260z and 280z. Very nice product with Dual 40 Amp Hella relays. $149.95

 

http://www.ceautoelectricsupply.com/h4headlightrelaykits.html

 

Edited December 16, 20159 yr by Chickenman

Nice!

Another suggestion is to also install the parking light relay.  I did this on my 240z in addition to the headlight relay from Dave and it does make a difference.  Plus, it takes more heat away from the headlight switch.

I recently reminded myself about the difference in heaadlight switch sets over the various years. I was shocked to be re-reminded of how fragile the early switch sets are compared to later ones in terms of the wiring not just the switch contacts. They increased the wire gauge after the series 1 cars that lead to the HL switches (not to mention moving the switch from the ground side to the fuse side), The switches and the contacts themselves are identical internally from 70-78. The wiring, not so much.

I can't emphasis enough the need to upgrade to a relay system no matter what type of headlight you end up using.

Don't forget to service (clean) the contacts where the new harness connects to the old head light connectors up front. Those things are exposed to the elements and are always grundgy.