stangs-R-me 120 Report post Posted July 1, 2011 Just finished installing a new ALLOY METAL PRODUCTS headlamp wiring harness on my car and it went very smoothly. Now pulled the alternator to change this little harness and my original is slightly different. My original harness has the ground wire from the plug going down to the engine block (where the battery ground goes) and then a larger wire comes back and attaches to the alternator case. The main black positive wire (in the center) is also larger on my original than the one in the replacement harness. My original harness is much more Heavy Duty, just that it is 42 years old and really should be replaced. Could this be the HD 55 A alternator option (vs. std 38 A) or because my car has A/C ?? See pics below ... anyone else run across this ?? Doug Quote Share this post Link to post Share on other sites
LindenBruce 27 Report post Posted July 1, 2011 Well, your new harness is the correct one. It's the same as my old harness and my new one. Here is a pic of my new harness. It's possible the alternator on your car now may have been transplanted from a different application somewhere in the past. That's why you're scratching your head. Hope this helps. Bruce Quote Share this post Link to post Share on other sites
stangs-R-me 120 Report post Posted July 1, 2011 Thanks Bruce, I thought that might be the case ... but ... I'd really like to find out what I've got. I'm going to try to contact Alloy Metal Products and see what they have to say. The Headlamp Harness wire in the mating plug appears to be the same size as the one in my old harness so it should be compatible with the larger wired alternator harness. More than likely what I've got is the H-D Alternator harness ... and knowing me, I've got the highest amp replacement alternator listed in the parts store data base for 1969 Mustang so I probably NEED this higher capacity harness !! Doug Quote Share this post Link to post Share on other sites
miketyler 15 Report post Posted July 1, 2011 Did they make a HD version of that alt harness? Everything was minimal back then. I ordered Concours battery cables for my car and they are only about 1/4" in dia. Quote Share this post Link to post Share on other sites
LindenBruce 27 Report post Posted July 1, 2011 Did they make a HD version of that alt harness? Everything was minimal back then. I ordered Concours battery cables for my car and they are only about 1/4" in dia. I'm not sure on that Doug. The only two harnesses I have ever seen are for tach and non tach applications. And the charge wire appears to be the same gauge between them. I believe the highest amperage alternator you could get for the mustangs was the 55a. I know when guys install higher amperage than that, the have to upgrade to a larger charge wire. But then again those would be G3 upgrades which are a completely different animal anyway. Bruce Quote Share this post Link to post Share on other sites
stangs-R-me 120 Report post Posted July 2, 2011 Did they make a HD version of that alt harness? Everything was minimal back then. I ordered Concours battery cables for my car and they are only about 1/4" in dia. I bought repro battery cables for my car back in the 80's and not only were they wimpy wire but they fell apart in about 2 years ... JUNK. The std. auto parts store ones I bought to replace them are still on the car today and still look good and solid. As far as the HD Alt harness ... look at my pics !! Was thinking maybe I swapped in a newer harness at some point. So I was looking at other repro alt harnesses for 70-up Mustangs and nothing newer will interchange with 1969 or older, so this can't be the case !! Tried to call Alloy today and phone just rang & rang ... maybe they are off on Friday. Doug Quote Share this post Link to post Share on other sites
stangs-R-me 120 Report post Posted July 2, 2011 I may have figured out this harness ... looks more like a '67-68 Cougar XR7 / Mustang w/o Tach 289-302 harness # C7ZZ-14305-B. Here are pics of this harness from 3 different vendors: http://www.cougarpartscatalog.com/c7zz-14305-b.html http://www.cjponyparts.com/ALTERNATOR-WIRING-HARNESS-6-CYL---SMALL-BLOCK-V8-W-O-TACH-1967-1968/p/WALT4A/ http://johnsmustang.com/Parts/details-2140.html Definitely think this harness is superior to C9ZZ-14305-S / '69 version due to the added Ground wire (can never have enough ground) but I can't really tell if the main power wire is actually a larger gauge like mine or not. Doug Quote Share this post Link to post Share on other sites
LindenBruce 27 Report post Posted July 2, 2011 Good job on tracking that down. Just as I thought it's from a different application than our 69's. But it should work just fine. Now the weak link will be the wire it attaches to in your headlight harness. And yes, these older cars need the best grounding they can get. Poor grounds will cause so many Gremlins it could drive a guy to start drinking!!! Bruce Quote Share this post Link to post Share on other sites
stangs-R-me 120 Report post Posted July 8, 2011 (edited) Well, I bit the bullet and ordered a '67-68 Harness from CJ last weekend and it came today (only a $20.36 gamble thanks to their supposed 15% off SALE). YES the main power wire is LARGER ... same size as main (headlamp) harness, guessing 12 GA. so wire sizes used in this '67-68 harness are all the same as my original. However it is not exactly the same as the original ... plug lead to main harness is longer and the ground leads going to the engine block are shorter so I could not re-use the wire guide and clamp from the original harness and route the exact same way. I made it work though and am much happier with this more HD harness than the "correct" '69 one. Also, this harness was NOT made by Alloy, it was made by Mr. Mustang. Doug Edited July 8, 2011 by stangs-R-me Quote Share this post Link to post Share on other sites
