87 n/a electrical drain issue
12-10-11, 06:04 PM
#1
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87 n/a electrical drain issue
car was working fine up until about a week ago.
all i did was put 2 10" subs in box with a 460 watt amp in it.
positive is wired up good and tight, remote is wired up good and tight, and the ground is grounded good.
every time i go to start the car it turns over real slow then after about 5 or 6 seconds it starts and the voltage goes up to 13.5 volts. if i let it idle, it will go down to almost 11 volts.
any suggestions on how i should seal up this electrical issue? 460 watts should not drain the battery, especially if the car is sitting over night without even being on.
all i did was put 2 10" subs in box with a 460 watt amp in it.
positive is wired up good and tight, remote is wired up good and tight, and the ground is grounded good.
every time i go to start the car it turns over real slow then after about 5 or 6 seconds it starts and the voltage goes up to 13.5 volts. if i let it idle, it will go down to almost 11 volts.
any suggestions on how i should seal up this electrical issue? 460 watts should not drain the battery, especially if the car is sitting over night without even being on.
12-10-11, 08:06 PM
#3
My guess is that the original alternator is not sufficient any more, therefore unnecessarily taxing the battery while it's running. This will likely kill the battery quickly if the alternator cannot meet the electrical demand of your new electronics. If it's the original 70A S4 alternator, it needs to go in the trash and you need to upgrade to an FD alternator (100A) or a mid-90's Ford Taurus alt (130A). There are write-ups in the archive on both installs.
12-10-11, 09:06 PM
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I highly advise the 130A Taurus alternator swap.
Remove the negative battery terminal, set a multimeter to AMP current (mA), one prong to the negative car terminal, one prong to the negative battery terminal, BE SURE ALL ELECTRICAL LOADS ARE OFF, now see if the multimeter is reading very very little current (mA) or zero... If it is displaying more than it should be, remove the 60A BTN fuse from the engine fuse box (so that you can open the door of the car without the lights coming on), go into the car and start pulling fuses from the fuse panel by your feet, one at a time. If that fuse doesn't get the multimeter to display zero, then put it back in and try another fuse. You can also try pulling other things... The way I found my drain, was by unplugging my turbo timer. The multimeter then displayed zero, and that's how I knew that was the problem.
Remove the negative battery terminal, set a multimeter to AMP current (mA), one prong to the negative car terminal, one prong to the negative battery terminal, BE SURE ALL ELECTRICAL LOADS ARE OFF, now see if the multimeter is reading very very little current (mA) or zero... If it is displaying more than it should be, remove the 60A BTN fuse from the engine fuse box (so that you can open the door of the car without the lights coming on), go into the car and start pulling fuses from the fuse panel by your feet, one at a time. If that fuse doesn't get the multimeter to display zero, then put it back in and try another fuse. You can also try pulling other things... The way I found my drain, was by unplugging my turbo timer. The multimeter then displayed zero, and that's how I knew that was the problem.
12-12-11, 06:46 PM
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Im having the same problems with mine, got my s4 alt tested and they said it was only putting out 12.3v and they said it was bad, idk if i should get a new replacement for 108$? or get an FD alt?
12-13-11, 12:21 AM
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I seen this on ebay, http://www.ebay.com/itm/1988-Mazda-R...item2c5ccc4682
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12-14-11, 01:12 PM
#8
That might do it. I'm not convinced that it's an FC alternator, based on the adapter pigtail. It's also $130, but it is at least brand new. If I were to have my FD alternator fail on me right now, I'd get a mid '90s Taurus alternator. Can't beat 130A, and you can get one for next to nothing used or new since they're so common.
12-14-11, 04:11 PM
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That might do it. I'm not convinced that it's an FC alternator, based on the adapter pigtail. It's also $130, but it is at least brand new. If I were to have my FD alternator fail on me right now, I'd get a mid '90s Taurus alternator. Can't beat 130A, and you can get one for next to nothing used or new since they're so common.
mario, that FD alternator would be a good starting point. If you're looking for a bit of extra amperage, you can go another route. I bought a brand new 3.8L mid 90's 130A Ford Taurus alternator for $160. I have NO problems with it, and NO regrets. There's a bit of modification going this direction (Taurus alt)... But nothing out of reach. Don't be scared by the brand new Taurus alternator price. You can get a used one for a hell of a lot cheaper, and it will still hold up.
Here are some 130A alternator links with great information:
https://www.rx7club.com/showthread.p...ht=130A+Taurus
https://www.rx7club.com/showthread.p...ht=130A+Taurus
12-15-11, 01:23 PM
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http://www.ebay.com/itm/1987-Mazda-R...item2c5f960472
Its a different ampage looks like the same thing? 130a
Its a different ampage looks like the same thing? 130a
12-15-11, 01:27 PM
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http://www.ebay.com/itm/1987-Mazda-R...item2c5f960472
Its a different ampage looks like the same thing? 130a
Its a different ampage looks like the same thing? 130a
12-15-11, 05:07 PM
#12
Although I fully understand that a little re-working of the alternator (i.e. re-winding) will give it a higher amperage rate, I don't know if I'd trust an Ebay item to be what it says it is. Especially if they're selling it as an FC alternator at 130A. A search for their website yielded this :
http://www.acealternators.com/alternators.html
Since 1937, and their alternator page is "coming soon". :/
http://www.acealternators.com/alternators.html
Since 1937, and their alternator page is "coming soon". :/
12-16-11, 04:37 PM
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I don't have a pigtail harness or the connector for my Taurus alternator. It would be so much more convenient, though. I have each alternator terminal individually wired with it's own connector... Which is somewhat annoying. If you can get the connector for the Taurus alternator, then +1. Be sure to follow the directions very thoroughly.
12-17-11, 11:34 AM
#15
Get your alternator, then find out which plug it is. Maybe someone else who has one can chime in.
http://store.alternatorparts.com/for...-products.aspx
One of those has to work.
http://store.alternatorparts.com/for...-products.aspx
One of those has to work.
12-17-11, 11:55 AM
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Get your alternator, then find out which plug it is. Maybe someone else who has one can chime in.
http://store.alternatorparts.com/for...-products.aspx
One of those has to work.
http://store.alternatorparts.com/for...-products.aspx
One of those has to work.
Here is the Taurus alternator...
12-17-11, 03:22 PM
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This is NOT the wiring for the Taurus alternator... This is only an example of what I posted above:
Your alternator is different from the alternator I posted. What year Taurus did you get that from??
12-18-11, 06:04 AM
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I'm not saying that it will not work. You'll have to figure out how to wire it up. It shouldn't be that complicated... You may just be able to adapt that to your S4 harness.
Your S4 wiring to your current alternator should be a two prong "T" shaped plug, with a B/W (Black/White) wire and a W/B (White/Black) wire. The B/W wire is switched power (Ignition switch). And the W/B wire goes to the dash (Voltage gauge). The "B+" terminal is pretty obvious... And the same concept from S4 alternator to Taurus alternator. You'll need to figure out which specific Taurus wire goes to whichever sepcific harness wire.
Here is an illustration of the FC (S4), FC (S5), and FD (S6) wiring:
Your S4 wiring to your current alternator should be a two prong "T" shaped plug, with a B/W (Black/White) wire and a W/B (White/Black) wire. The B/W wire is switched power (Ignition switch). And the W/B wire goes to the dash (Voltage gauge). The "B+" terminal is pretty obvious... And the same concept from S4 alternator to Taurus alternator. You'll need to figure out which specific Taurus wire goes to whichever sepcific harness wire.
Here is an illustration of the FC (S4), FC (S5), and FD (S6) wiring: