Fog lights into High/Lows - 1985 300D

[southofantarctica]

Looks like I'm a glutton for punishment, I went out and bought another cheap non-running MB off Craigslist. Found a '85 300D that had been sitting for over a year and long story short, got it running (runs like a scalded ape too!!)

However, my amber fogs are need of replacement. Decided that while I was at it, might as well upgrade my night time visibility and ordered me a set of E-code Hella 5.75" H4s. I am wanting to run them as dual High/Lows and install relays for better light output.

So the question is how can I get all that to happen? I've done a lot of reading and a whole mess of searching, but most of all the info has to do installing 7".

Y'all came through for me in the past, hope you can help this time too!

[ichris93]

Originally Posted by southofantarctica

Looks like I'm a glutton for punishment, I went out and bought another cheap non-running MB off Craigslist. Found a '85 300D that had been sitting for over a year and long story short, got it running (runs like a scalded ape too!!)

However, my amber fogs are need of replacement. Decided that while I was at it, might as well upgrade my night time visibility and ordered me a set of E-code Hella 5.75" H4s. I am wanting to run them as dual High/Lows and install relays for better light output.

So the question is how can I get all that to happen? I've done a lot of reading and a whole mess of searching, but most of all the info has to do installing 7".

Y'all came through for me in the past, hope you can help this time too!

Do you want them to respond identically to the 7"?

[ichris93]

Can you follow this?

[southofantarctica]

Originally Posted by ichris93

Do you want them to respond identically to the 7"?

Ideally, yes. That way I could save the fog option on the switch for something down the road.

[southofantarctica]

Originally Posted by ichris93

Can you follow this?

I think so.... If I read that right, there are three relays that need to be run for each lens and are getting power directly from the alternator (or the battery)? Is that the gist of what is going on?

[ichris93]

Originally Posted by southofantarctica

I think so.... If I read that right, there are three relays that need to be run for each lens and are getting power directly from the alternator (or the battery)? Is that the gist of what is going on?

Here's my idea, relay 1 gets power straight from the battery. Relay 1 gets switched on my the fog light switch. This way the 5.75 are only on when the relay is on. Then from that relay you have two lines, one going to a high relay and one going to a low relay. Those get switched by the high and low of the 7. If you get relays rated high enough you will on need 3 and they can both run off of them. Don't forget to put inline fuses as well!

[southofantarctica]

Got it. Sounds straight forward enough, although I'll find out Wednesday if my limited electrical skills are up to the job. Thanks for the reminder of inline fuses, I appreciate it!

[ichris93]

Originally Posted by southofantarctica

Got it. Sounds straight forward enough, although I'll find out Wednesday if my limited electrical skills are up to the job. Thanks for the reminder of inline fuses, I appreciate it!

If you know what a relay is and how to wire one, I think you can handle it

You're welcome! The first time I wired a car, I forgot the fuses and a wire got stripped on a sharp metal edge. Then there was a short to ground and the wire melted. I had to stop the car and turn it off until I could undo my wiring! Could've caused a fire!