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Discussion Starter · #1 ·
My son upgraded his daily drivers(92 Explorer) sound system. The speakers needed to be replaced. There appears to be no common sense the way ford wired the speakers. There is no common color coding of wires, even had a mechanic friend of mine look in the wiring diagram of his ford manual. It didn't show positive or negative and nothing on the speakers or plugs indicated it either. Got on the net and found out if you use a 9 volt battery(+ & -) and touch it to the factory speaker plug wires when the cone moves out that is the correct polarity of the speaker. Neat trick thought I'd share it. Now we can make sure they are wired correctly and not be "out of phase". Pete
 

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That's an old trick I've used since around 1960. Learned that from an article in Popular Electronics about that time. I've always used a 1 1/2 volt battery to determine speaker polarity. When the cone moves OUT, the speaker terminal which is connected to the positive battery terminal is the + side. Great tip then and still helps today! ;)
 

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I too use the battery tip to check polarity on speakers or just to quickly pop test them. The only problem I've ever had with the battery pop check is if the speakers are all blown. They won't make a noise with the battery.
Most of the car's I've worked on the last 20+ years have the same special plug on the front speakers and rear speakers (there are exceptions of course due to some geek designer wanting some type of job security that just has to make things different). The car manufacturers normally don't have a specific left front speaker, right front speaker, etc unless it is possibly a high end system. This means the guy on the assembly line can grab a front speaker and put it either in the left door or the right door and the speaker plugs are the same and so is the polarity. The factory plugs are keyed to where they can only be connected one way.
I personally try and use speaker harness adaptor plugs that are out there from Metra and these adaptor plugs are made to plug right onto the factory wire end that came off of the factory speaker and then allow you to plug in a new speaker that has the large and small flat terminals on it. The wires on the adaptor plug are also color coded (black/negative, white/positive).
If I have a car that there is no speaker harness available for it then I look at the plug and see how it is keyed and pick the wire let's say to the left of the key slot and make that the positive and the other one will be the negative. I do the same for the other remaining speakers and they will all be in phase with each other electrically.
If it is a new car and there is no adaptor available, go back on the wire some, strip back the insulation, wrap the new wire onto it and then solder it together. Wrap each connection with electrical tape and then wrap both together and then put a wire tie on the tape to keep it from unraveling. If the factory plug is still still on the wires, then you can always reinstall the factory speakers and not have to track down a missing plug.
Jim/Saint Louis
 

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Discussion Starter · #4 ·
Jim that's a good idea. I wasn't aware there were adapters available that allowed you to use the factory plug. Had I known that that's what I would have done. Where can one find these adapters? I'd need one for a 92 Explorer and 85 Camaro. While it's still apart I'm not opposed to doing it that way. Any info would be appreciated. Thanks Pete
 

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Pete,
I see you are in Missouri also. I don't know what part of the state you are in but try calling the local audio shops around you and and see if they handle Metra brand harness'.
I'm at home today (cough/cough/sick/sick) and don't have a book to look the particulars up but the prefix on the spaker harness' are 72-???? (I'm thinking maybe a 72-4568 or 72-4500 for the GM and 72-5211 for the Ford but this is off memory (it fades with age).
I'm thinking Metra is online (metraonline.com ?) and may be some help.
You can always PM me and when I'm at work tomorrow I could look it up and see if I have them in stock.
I'm not wanting to get in trouble with the board but some shops around you may not have them and if I have them then maybe we can get you going. If not there are probably online places that can do the same for you.
I do know not a lot of shops carry them and there are still a lot of hacks out there but I would rather see you use a part that is a time saver and not have to butcher up the factory wiring.
Jim/Saint Louis
 

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Discussion Starter · #7 ·
Thanks for all the info Jim. I'm about 35 miles east of the closest Brandsmart(I'm in Lexington, 25 miles north of I-70) but I will try there this weekend. With my "guessing" prior to the battery tip I was three for four on guessing the polarity of the speakers, only one was out of phase. Now I'll get the adapters and all will be right. Once again THANKS!! Pete
 

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Pete,
I'm glad I could help. And if you need to replace the radio in your cars, they also make radio harness adaptors and antenna adaptors.
Maybe I'll see you at a Missouri car show next year.

Jim

PS:
I tried the Metra link and tried a search for 72-4500 and a search for 724500 and they didn't show that part number. It is in the catalog but evidentally not on-line (figures). But at least other companies like Parts Express had a picture of them.
 
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