How to wire H4 MSP headlight assembly into a P5

[hodgson]

This is a howto expansion on this excellent post. I just followed his instructions and completed the process, and I found myself wishing for some detailed photos, so here are some shots I took as I was wiring my headlights. My highs and lows work now.

The side markers in the headlight assembly still aren't lighting up because nothing is connected to them. Can I wire them in parallel to the front clip side marker in my car? Might be overkill. Might snap the fuse.

Anyway here are some photos of the tools I used and how I wired it all up.

You will need:
1. pliers to crimp things with.
2. something to cut wire with
3. a wire stripper (not your teeth, rambo)
4. some mini screwdrivers are nice
5. 2x Sorenson MR78 relays
6. 2x H4 connectors. the ones I bought were crappy but seem to work.

You can see some of this stuff pictured here:

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I also used these 3M splicer thingies pictured here, but I forgot where I got them. They are great for letting you not cut off the OEM connector and not destroy the wire to them but still get power spliced into them.

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And here's the relay in question:

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Here's a slightly more detailed drawing, based on thewrench's information that you may find helpful.

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And here's what my sloppy finished product looks like on the driver's side.

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I taped everything up to avoid having moisture problems, and hid it all away as best I could. On the driver's side I figured it was best not to have the relay and wires laying on the radiator hosts which are all around, and on the pass. side there is a pully and belt situation that it would be bad to have your wires get into.

So that's that! Now I have high beams and low beams in my MSP headlights on my Protege. Now to get the pesky Driver's side turn signals to work and I'm all good!

 

[TheMAN]

you need to get a relay socket dude! and that relay itself looks pretty weak... I'd get a beefy bosch 30 amp relay with socket if I were you

 

[hodgson]

you need to get a relay socket dude! and that relay itself looks pretty weak... I'd get a beefy bosch 30 amp relay with socket if I were you

Good advice. but I went with the giant electrical tape ball option instead, 'cause that's how I roll. I'm pretty sure the mr78 is a 30-amp relay, though.

 

[TheMAN]

those small GM style relays tend to fail easily... if it ain't a big ass relay, the contacts in there aren't big and heavy duty!

 

[Diehonda]

you need to get a relay socket dude! and that relay itself looks pretty weak... I'd get a beefy bosch 30 amp relay with socket if I were you

30 amp relay:
Bosch part #0 332 204 150
Hella part # 960 388 07
Porter & Brumfield # VF4-45F11


What relay socket would you recommend?

 

[triikster]

Dang, I attempted this today and although it looked pretty simple, now the low beams do not work and there is only light when the high beams are on (though I am not sure if it is actually the high or low that is on). Any ideas?

 

[triikster]

Never mind. I paid $60 to have it fixed. They said that the diagram that I had a few wires backwards. At least it works now.

 

[Diehonda]

Did you wire it as the diagram listed above? Can you take a picture of the wire set up as it is now? That way the correct way can be shown.

Thanks!
​

 

[triikster]

Sorry, they cleaned it up and wrapped it, and now you cant see what goes where.

 

[ho bag]

Just wondering why you would want to goto MSP headlights? Personally i like the p5 lights best.

Seams like a downgrade to me.

 

[TreFlip999]

Just wondering why you would want to goto MSP headlights? Personally i like the p5 lights best.

Seams like a downgrade to me.

Cause they are are hot.

 

[ho bag]

Paint your P5 headlights and they will be hotter!

 

[TreFlip999]

Paint your P5 headlights and they will be hotter!

I turned around and sold my P5 headlights and made a profit so it was win win for me...plus they take a little bit of attention off the bumper side marker that im too lazy to take off

 

[thewrench]

Those relays have been on my car since that post with no problems at all. Of course I run 2 relays, one for each side, I'm sure that lowers the load.

Thanks for the credit, btw.

 

[ForceFed]

Just wondering why you would want to goto MSP headlights? Personally i like the p5 lights best.

Seams like a downgrade to me.

THe Single Bulb Sedan Setup has a much better Beam pattern and cut off Vs. the P5 Lights.
SO no..It should be an upgrade.

 

[Diehonda]

The can of worms has been opened. Some people swear by the P5 lights. Others by the sedan lights.

Personally I like the ability to change to the black sedan lights for less cost than getting new P5 lights and painting them.


I do like the beam pattern and cut off more in the sedan but with the addition of my 380K candlepower fogs I feel that I have maximized my visibility. The P5 lights are good looking, I just don't like the overall cost to replace them.