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Posted by: SKL1 May 12 2013, 07:27 PM

Putting in the 100W hi beam H4's and need the wiring diagram to install the relay(s) so the 40 year old wiring system can handle it.
Can't find it anywhere and search wasn't helpful...

TIA.

Posted by: Vacca Rabite May 12 2013, 07:32 PM

Get relays from FLAPS and the diagram is on the box. Makes it really easy.
If you are running big lights like that I'd make the power run all the way back to the battery (remember to keep it fused).

Posted by: kg6dxn May 12 2013, 09:32 PM

Read this...

 Relay_Book.pdf ( 1.08mb ) Number of downloads: 214

Posted by: SirAndy May 12 2013, 09:41 PM

I'm not sure the stock wires can handle the 100W in the long run.

Posted by: Cap'n Krusty May 12 2013, 10:33 PM

That's why you run relays. Big wires from the battery to the relays, big wire from the relays to the bulbs, big ground wires. The stock wiring is used to activate the relays. We do this all the time in Audis in order to save the combi switches, even with stock bulbs.

The Cap'n

Posted by: SirAndy May 12 2013, 10:56 PM

I know. That's why i agreed with Zach's post who basically said the same thing ...

Posted by: SKL1 May 13 2013, 05:47 AM

I may be an idiot, but what is FLAPS?? I see it all the time and don't know what it stands for...

Posted by: Rleog May 13 2013, 06:14 AM

Friendly Local Auto Parts Store, or, many other more creative versions.

Posted by: jim_hoyland May 13 2013, 07:10 AM

What size wires should be used:

Battery to relay
Relay to light(s)
Min Amperage of relay

Posted by: 396 May 13 2013, 07:29 AM

thank you

Posted by: orthobiz Sep 3 2013, 04:55 PM

I don't see wire gauge size in the "Relay Book" linked in one of the responses.

Paul

Posted by: r_towle Sep 3 2013, 04:59 PM

Volts * Amps = Watts
12 V * ?Amps = 100 Watts
OR
? Amps =100W/12V
OR
8.33 Amps = 100W/12V
Use a 10Amp fuse inline and you can get by with 16Ga wire.

Read the AMP draw on the device you will be using.
It will be on the package somewhere.

rich

Posted by: r_towle Sep 3 2013, 05:09 PM

Oh,

Only use the stock wiring for the trigger on the relay.
The stock light switch is already over stressed, it will melt, and they are NLA anywhere.

ITs a pain, but run new wires up through the tunnel, into the interior, up over the steering column (zipties) and through the main grommet into the front trunk to power those lights.

Rich

Posted by: orthobiz Sep 3 2013, 06:24 PM

Thanks.

Paul

Posted by: jim_hoyland Sep 3 2013, 07:01 PM

Will one relay power low beams and high beams ? Or, are two relays needed ?

Posted by: kg6dxn Sep 3 2013, 08:59 PM

2 relays required

Posted by: r_towle Sep 3 2013, 09:02 PM

It's two different circuits, so two relays are required.

One larger wire for dedicated power to a common jumpered pole to supply power for both is ok, you don't use both circuits at the same time.

Rich

Posted by: Jeff Bowlsby Sep 3 2013, 10:41 PM

Here is the wiring diagram for the high/low beams + ground headlight circuits.

As a place to start for design purposes, consider the factory main power wire off the headlight switch to the fuses as 14 AWG, from the fuses to each headlight and ground wires are 16 AWG. As I recall the wiring is not as much of an issue as the ehadlight switch in terms of ampacity. Hopefully someone will figure out the new circuitry configuration and relay configuration, wire gages required for specific lamp sizes, and post it.

The headlights are L1/L2.


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Posted by: jim_hoyland Sep 4 2013, 09:31 AM

See: http://www.rowand.net/Shop/Tech/WiringHeadlightRelays.htm

Most of your questions are answered plus there is a neat wiring diagram.


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