voltage pegged at 16V
#1
voltage pegged at 16V
Okay I know this means I need a new voltage regulator, my Haynes manual says how to replace it, and I imagine I can get a new one at my local auto store. I haven't verified the voltage with a voltmeter yet, since mine's broken and I'm waiting for a new one to ship. But it reads 12.5V when the engine isn't running, and it goes a little beyond 16V at higher rpms, so I suspect it's accurate.
Problem is, the last owner already replaced the alternator. Sure enough, it was the only clean thing in the engine bay and its belt was new while I had to replace the other belts. That was 8,000 miles ago.
I remember reading somewhere on these forums about someone who replaced their alternator multiple times. Even if I could search for it, the search tool is being fussy. So can someone tell me what to check so I don't blow another voltage regulator?
Problem is, the last owner already replaced the alternator. Sure enough, it was the only clean thing in the engine bay and its belt was new while I had to replace the other belts. That was 8,000 miles ago.
I remember reading somewhere on these forums about someone who replaced their alternator multiple times. Even if I could search for it, the search tool is being fussy. So can someone tell me what to check so I don't blow another voltage regulator?
#2
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That voltage is created when the engine is running and the alternator is the source of the voltage. Your problem must be in the alternator weather it be the voltage regulator or something in the alternator its going to be comming from that component.
And above all else get the right voltage before you go worrying about this too much. They have charging system testers at autozone that can tell you exactly what its putting out. Compare it to spec then worry about the voltage.
And above all else get the right voltage before you go worrying about this too much. They have charging system testers at autozone that can tell you exactly what its putting out. Compare it to spec then worry about the voltage.
#3
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yea you can take your alternator over to auto zone to get it tested. although im almost sure that the regulator is internal on the s4 alternator so when he replaced it that should be a new alternator. i would make sure the regulator is hooked up. plug behind the alternator. a bad battery can be mistaken for a bad regulator. if your batttery is dead your alternator is working double time. check voltage after the car has been sitting for a while... i wouldnt always jump to conclusions, that may be why the alternator was replaced in the first place, although it may not be the problem... Good chance that it is the regualtor but i would also check the other stuff.
#5
Originally Posted by Icemark
The regulator is internal in the FC and FD alts.
If you have a bad regulator, you have a bad alt
If you have a bad regulator, you have a bad alt
The voltage has been reading normal for the last 8,000 miles since I got the car: ~12.5V w/ engine off, ~14V w/ engine on. It just now started reading 16V when I started my car today, unless I didn't notice it last time I drove. That's unlikely. Belt tension seems normal, about 1/2" of deflection.
What does the regulator plug look like? Where exactly is it? I see 4 plugs near the alternator on its side. EDIT: I found a plug that plugs into the back of the alternator. I assume that's what you mean. It's wiggling but I'm having trouble pulling it out. I'm gonna get my pliers, pull it, look at it, clean it maybe and plug it back it good.
Is there anything that could have caused this alternator and the last one to fail that I should check?
Last edited by ericgrau; 04-01-07 at 11:01 PM.
#6
Former Moderator. RIP Icemark.
sure you can do that, usually easier just to replace the alt.
And there is only one plug on the alt and a positive post output terminal. Again the regulator is internal to the alt. To replace it, you would need to remove the alt.
And don't drive the car at 16 volts. The ECU and lights are designed for 15 volts maximum. Running them at 16 volts will burn them up and let the genie escape.
And there is only one plug on the alt and a positive post output terminal. Again the regulator is internal to the alt. To replace it, you would need to remove the alt.
And don't drive the car at 16 volts. The ECU and lights are designed for 15 volts maximum. Running them at 16 volts will burn them up and let the genie escape.
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#8
hahaha my soldering gun is 140w. that thing solders 2-4 ga. wire in seconds. it also melts the plasting sheathing. no good for electronics though. I agree, get a new alt. Regulator bad= bad alt. There could be other factors as to the 16v output beyond the regulator.
#9
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Originally Posted by Icemark
And don't drive the car at 16 volts. The ECU and lights are designed for 15 volts maximum. Running them at 16 volts will burn them up and let the genie escape.
#10
The plug in the back of the alt seemed fine. I ran my car again for a minute. Same problem. The alt seemed really hot too after only a minute, dunno if that's normal.
Why might this alt have blown so fast? Cheap rebuilt alt maybe? What are the "other things" I should check first? I saw some charging system items listed in the Haynes manual that I will check when I get my voltmeter, but those don't seem related.
So it's pretty likely that I just need to replace the alternator? Where do I get a replacement? At an auto-store? Or do I bring/send my old alternator somewhere? Where? There's a mechanic within close walking distance.
Is it safe to drive short distances? Like 15 minutes each way to the auto-store? (assuming the typical heavy traffic around here; it's only 1-2 miles away).
Why might this alt have blown so fast? Cheap rebuilt alt maybe? What are the "other things" I should check first? I saw some charging system items listed in the Haynes manual that I will check when I get my voltmeter, but those don't seem related.
So it's pretty likely that I just need to replace the alternator? Where do I get a replacement? At an auto-store? Or do I bring/send my old alternator somewhere? Where? There's a mechanic within close walking distance.
Is it safe to drive short distances? Like 15 minutes each way to the auto-store? (assuming the typical heavy traffic around here; it's only 1-2 miles away).
#12
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Originally Posted by RoughRex
I suck at electronics, more of a mechanical guy. .
#13
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Originally Posted by NZConvertible
Trust me, you need a huge soldering iron to desolder the regulator. I held my 30W iron on it for ten minutes and it didn't make a mark. Just pay to get it rebuilt.
#15
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I got a reman alternator last year with a lifetime warranty. I just replaced it yesterday with another reman for free since that one was bad (bearing or something). Just spend the money and get something with a lifetime warranty, whether it be free or reman. They didn't even test it... I just brought it in and told them it was bad.
Putting out 13.2v with my lights/brakes on wasn't making me happy. If I could of tried it with the A/C on who knows what it would of read.
Putting out 13.2v with my lights/brakes on wasn't making me happy. If I could of tried it with the A/C on who knows what it would of read.
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