Project "Face Off": 1980 Mercury Capri aero to four eye Progress Thread!

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Really need someone to explain how to convert the wiring from the Aero 3-wire 2-headlight setup to the four-eyed 5-wire/4-headlight setup.


Since the car was originally a 4 eye, shouldn't there be a sort of "reverse hack job" approach to this? Or did they "do it right" and swap out the whole headlight harness? That might be a better/easier solution, just swap the light harness with an older one.
 
Since the car was originally a 4 eye, shouldn't there be a sort of "reverse hack job" approach to this? Or did they "do it right" and swap out the whole headlight harness? That might be a better/easier solution, just swap the light harness with an older one.

They did everything right and I mean EVERYTHING so basically, it's like we're converting an aero car to four eye.
 
Nuttin to it Dave. You will need 4 two prong headlight plugs. The current one you have will have a ground a low beam positive and a high beam positive. Gonna need a voltage tester to see what wire is hot for the low/high beams. Then you take the low beam positive and the ground and run it to one of the new two prong plugs and run the ground to the other terminal on the plug. Then you put the high beam positive on the other plug and just run a grouns wire to the other pin and you are good to go. :nice:
BTW, the low beams are the outside most lights :p
 
Nuttin to it Dave. You will need 4 two prong headlight plugs. The current one you have will have a ground a low beam positive and a high beam positive. Gonna need a voltage tester to see what wire is hot for the low/high beams. Then you take the low beam positive and the ground and run it to one of the new two prong plugs and run the ground to the other terminal on the plug. Then you put the high beam positive on the other plug and just run a grouns wire to the other pin and you are good to go. :nice:
BTW, the low beams are the outside most lights :p

Hmmm ... so, we'll need basically four high-beam bulbs? Because the inside ones are the high beams and they're only two-prong deals. (The outer bulbs/plugs are four-prong.) Either that, or I guess I could just hook up one power wire on each of the low-beam plugs and one ground and just leave the third undone. :shrug:

I've got a multimeter, but I think it's kinda halfway fried. Only the continuity part seems to work. :(
 
Hmmm ... so, we'll need basically four high-beam bulbs? Because the inside ones are the high beams and they're only two-prong deals. (The outer bulbs/plugs are four-prong.) Either that, or I guess I could just hook up one power wire on each of the low-beam plugs and one ground and just leave the third undone. :shrug:

I've got a multimeter, but I think it's kinda halfway fried. Only the continuity part seems to work. :(

If you do it like that then you'll loose the ability to have all four lights working when the highbeams are switched on; the third prong is for a parallel. I'll explain later when I get home.
 
Hey Lynn / Dave, did either of you create a list of what parts are needed to do 100% complete the exterior? Interested to see whats needed.

Well, being that her Capri is kinda hacked up irreversibly in some spots from the four-eye-to-Aero conversion (such as the tail lights and sail panels), and because it would be wayyyyyyy too much of a project to go swapping out the whole interior again, not everything is getting swapped back 100%. As far as the exterior, she still has the original Capri fenders on the front and rear, so that part's all good, but she'll still need some of the mid-level trim (we got the front and rear fender sections, but not the doors or the parts just ahead and behind the doors - might be able to get away without having trim there, a-la the Black Pearl), as well as a rear bumper.

The Saleen wing's staying on there until she can find a three-piece Pace Car/early Capri style ducktail spoiler like the pre-bubble-hatched Capris had - I tried convincing her to go with the bubble hatch, since the red Capri where we got the nose and hood had a perfectly good hatch and rear bumper, but she insists that she hates both the bubble hatch and the tail lights on the thing. So, until she scores another Capri rear bumper, if/when that happens anytime soon, it'll still say "Mustang" on the rear. :nonono: That is, unless they make some kind of a flexible Bondo or something that could be used to fill in the lettering on the rear bumper...? (Although even then, the trim won't quite match the bumper...)

She's also kinda obsessing over getting an RS-style airdam for the thing. She was all but fapping to pics of one online last night. :D
 
:doh: Crap, its been so long since I have seen a 4 light setup I forgot how they looked. Yeah, the other two connections are slaved to the high beam so the low beam stays partially on (it may have a second filiment but not sure) when the highs are on. I am sure a 4-eye guru on here will be able to tell you which wire is what :nice:
 
I should draw up a diagram or somethin', I guess. It's kinda hard to explain.

The Aero headlights have bulbs with two filaments each, so I'm guessing "high beams" for that only amounts to powering up the second filament in each bulb and running it on the same ground wire. I dunno if the composite headlight bulbs draw less wattage/amps or the same as the old sealed-beam ones, but if they draw the same, then I could get away with just splicing into the stock Aero wires with the sealed beam bulbs; otherwise, I'm gonna have to run separate grounds to the frame for all of the bulbs. Actually, now that I think about it, that might work a little better, anyhow. Or does it need to follow the stock ground wires all the way back to something somewhere else? :shrug:

How about this for a ghetto diagram:

(STOCK AERO WIRE SETUP)

Positive low-beam \
Positive high-beam >---- composite (9004) bulb (driver side)
Negative (ground) /

Positive low-beam \
Positive high-beam >---- composite (9004) bulb (passenger side)
Negative (ground) /



(STOCK FOUR-EYE WIRE SETUP)

Positive low-beam \
Positive high-beam >---- sealed beam (H4656) driver side
Negative (ground) /


Positive high-beam \
................................------ sealed beam (4651) driver side
Negative (ground) /


Positive high-beam \
................................----- sealed beam (4651) passenger side
Negative (ground) /


Positive low-beam \
Positive high-beam >---- sealed beam (H4656) passenger side
Negative (ground) /



(HYPOTHETICAL AERO-TO-FOUR-EYE SETUP)

Positive low-beam (driver side) \ / Low beam (H4656)
................................................... >Negative ground for low AND high beam (driver side)
Positive high-beam (driver side) / \ High beam (H4651)


Positive high-beam (passenger side) \ / Low beam (H4656)
.......................................................... > Negative ground for low AND high beam (driver side)
Positive low-beam (passenger side) / \ High beam (H4651)

:shrug:
 
You can do that but I would run a seperate ground for the high beams. Just because I like a good solid ground.
Also, dosent the low beam only have 3 terminals on it? + low, + high and - ? If that is so then you will nees to run a wire from the high beams + to that other low beam terminal and that will allow the low beam to stay on when the highs are on.

Best thing to do would be to test the voltage on the three terminals you have now. Find the one that has power in the low beam position and then switch your high beams on and see if it still has power on it. If it does then you dont have to run a wire to the other side of the bulb to the high beams positive.
Basically the low beams will run normally when the brights are on and not dim like they are supposed to. Just means you will have more light that way :nice: But that is also a reason to run a seperate ground for the brights so you dont run too much current through one small ground wire :shrug:
 
You can do that but I would run a seperate ground for the high beams. Just because I like a good solid ground.
Also, dosent the low beam only have 3 terminals on it? + low, + high and - ? If that is so then you will nees to run a wire from the high beams + to that other low beam terminal and that will allow the low beam to stay on when the highs are on.

Best thing to do would be to test the voltage on the three terminals you have now. Find the one that has power in the low beam position and then switch your high beams on and see if it still has power on it. If it does then you dont have to run a wire to the other side of the bulb to the high beams positive.
Basically the low beams will run normally when the brights are on and not dim like they are supposed to. Just means you will have more light that way :nice: But that is also a reason to run a seperate ground for the brights so you dont run too much current through one small ground wire :shrug:

Ah. Yeah, that makes sense. If I can clean off the wires enough to figure what color is what, I can probably determine which is low-beam positive and which is high-beam positive by that, and just splice 'em in like that from there, and then just run fresh grounds from the bulbs to the frame. :nice:

This is really the only hard part of the swap, it seems, as everything else is pretty much just a matter of unbolting the Aero parts and bolting on/lining up the four-eyed parts. Probably won't try to tackle this until next weekend, though. Trying to decide whether or not to paint the parts before putting 'em on, as I'm afraid I'll just scratch and gouge the hell out of them in the process of installing everything. :shrug: