FC S4 NA Changed Alternator Now Won't Start
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The B/G wire comes from the engine fuse box and is powered by the EGI INJ fuse so either the fuse is bad or the wire is loose underneath the fuse box as suggested earlier or the wire is grounded out, so you need to see which of these possibilities it is and shouldn't be too hard to figure out. As for the B/W wire, it's located in the two wire plug of the Main Relay. If one wire is Black then the other wire must be B/W but if the B/G wire in the four wire plug is w/o voltage then this is likely your problem and not the B/W wire..
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B/G has 12v
W/B has 12v
B/W @ main relay has 1.9v
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B/W under dash in the white clip for the Open Circuit Relay has 2v
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If this relay clicks w/key to on then the B/W wire has the proper voltage and the B/Y and B/W coming from the 4 wire relay plug would have battery voltage w/key to on as well if the B/W wire from the two wire plug relay had proper voltage.
Are you sure the 15 amp Engine fuse is good? This is the fuse that powers the B/W wire in the 2 wire plug. If the fuse was good then the B/W wire at the Circuit Opening Relay, top row middle position, would have voltage w/key to on as both of these B/W wires are powered by the same fuse.
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Are you sure the 15 amp Engine fuse is good? This is the fuse that powers the B/W wire in the 2 wire plug. If the fuse was good then the B/W wire at the Circuit Opening Relay, top row middle position, would have voltage w/key to on as both of these B/W wires are powered by the same fuse.
I had 12v to the b/w a few days ago...now it is giving the 2v.
Could the ignition switch be causing this?
Lets apply some common sense to the situation. If the Engine fuse powers different items and some of these items have voltage w/key to on while the others did not then the ignition switch could not be the cause. This is why you were asked to check the wire at the Circuit Opening Relay. If you don't want to check that wire then check the B/W wire at the back of the alternator as it is also powered by the same Engine fuse.
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Lets apply some common sense to the situation. If the Engine fuse powers different items and some of these items have voltage w/key to on while the others did not then the ignition switch could not be the cause. This is why you were asked to check the wire at the Circuit Opening Relay. If you don't want to check that wire then check the B/W wire at the back of the alternator as it is also powered by the same Engine fuse.
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Lets apply some common sense to the situation. If the Engine fuse powers different items and some of these items have voltage w/key to on while the others did not then the ignition switch could not be the cause. This is why you were asked to check the wire at the Circuit Opening Relay. If you don't want to check that wire then check the B/W wire at the back of the alternator as it is also powered by the same Engine fuse.
Battery is @ 12+ volts
Then you'll need to check a two wire plug under the dash that connects to the ignition switch. The plug from the Front harness has two wires, one is solid Black and the other wire is Black/White. The pigtail of wires coming from the ignition switch is only about a foot long so it should be rather easy to locate this two wire plug. The wires are rather thick. The Black wire has constant voltage as it is connected to your battery. The B/W wire should have voltage w/key to on. This wire powers the Engine fuse that powers the alternator, Circuit Opening Relay , Main Relay and another relay on automatics.
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The b/w opening relay had the same as the battery voltage a few days ago and now it is at the 2volts. Replaced every fuse.
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Then you'll need to check a two wire plug under the dash that connects to the ignition switch. The plug from the Front harness has two wires, one is solid Black and the other wire is Black/White. The pigtail of wires coming from the ignition switch is only about a foot long so it should be rather easy to locate this two wire plug. The wires are rather thick. The Black wire has constant voltage as it is connected to your battery. The B/W wire should have voltage w/key to on. This wire powers the Engine fuse that powers the alternator, Circuit Opening Relay , Main Relay and another relay on automatics.
And one way to prove that the ignition switch is bein powered by the battery would be to see if either the wipers or turn signals work w/key to on. If they don't then the switch is not receiving voltage from the battery.
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Do you know if an 1988 Mazda 323 ignition switch is the same as an the s4?
Found one local, brand new for 50 bucks, but the parts shops use the same photo for all of them.
I wouldn't know, but I doubt it. If you checked out the item at an online web site that supplies these switches then it should also tell you if their item number is the same or what other vehicles the part is compatible with.
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I guess you could disconnect the two wire plug, jumper the Black wire, turn key to on, measure the wire that would have connected the B/W wire for voltage. If it doesn't have it then you verified the switch is the problem. When these things go bad it is usually the pigtail/switch part and not the key cylinder but this is not always the case.
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I guess you could disconnect the two wire plug, jumper the Black wire, turn key to on, measure the wire that would have connected the B/W wire for voltage. If it doesn't have it then you verified the switch is the problem. When these things go bad it is usually the pigtail/switch part and not the key cylinder but this is not always the case.


