H4 Fitment ?

[GotaT]

I have a 71 Targa and have been searching for H4's to fit into my buckets. Will any H4's work, will some of them not work.. If so which, or what will I need to find for correct fitment? part #'s could help.?

Ive come across some from a 74... ???

Is the relay necessary? If so, whats the wiring schematic for it?

Thanks!

[Bill Verburg]

Originally Posted by GotaT

I have a 71 Targa and have been searching for H4's to fit into my buckets. Will any H4's work, will some of them not work.. If so which, or what will I need to find for correct fitment? part #'s could help.?

Ive come across some from a 74... ???

Is the relay necessary? If so, whats the wiring schematic for it?

Thanks!

If you are just replacing the stock US DoT sealed beams, then yes, any 7" round H4 will do, all US cars from Day1 till sometime after the '84 Carreras came out used the same 7" sealed beam unit.

relays are recommended for all 911s, but are really desireable for those using high wattage H1 or H4 bulbs, the stock headlights were something like 55watts, i've seen up to 100watt H4s used on the stock circuit, all the currect goes thru the steering column switch which will have a limited life expectancy.

wiring diagrams have been posted a # of times, try a search.

[GotaT]

For clarification the H4's Im referring to are the entire assemblies. The "slant back" style lamps.

If using 55 watt bulbs is the relay necessary or only if using higher wattage?
Thanks

[Bill Verburg]

Originally Posted by GotaT

For clarification the H4's Im referring to are the entire assemblies. The "slant back" style lamps.

If using 55 watt bulbs is the relay necessary or only if using higher wattage?
Thanks

OK, same answer. All the RoW cars used their own light assemblies w/ either 2x H1 or 1xH4 bulbs, sometimes w/ an additional city bulb. They can be used on all US cars except that sometime in the '84- 89Carrera model run they started using H5s that are similar in appearanve to the RoW H1/H4 but use a different electical connector.

THe US and RoW headlights prior to the intro of the H5 bulbs were freeely interchangeable.

The factory felt ok w/o relays on the 55 watt bulbs. I wouldn't

[GotaT]

So then, any slant style H4 pre 80's is safe to say will bolt up and the electricals will work as well. Consider adding the relay with 55watts.

I heard that there was some sort of vacuum something or other.. really not sure about that.. are you familiar?