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idiot lights always on

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Old 09-05-12, 01:33 AM
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idiot lights always on

If the car is running, they are all on. And I can't seem to get the alternator to charge.. Just swapped it out a few minutes ago. checked at the alt output, its never above 12.XX.

interior guage didnt read anything above 12 till I revved to about 6K

Any ideas?? The grounds should be fine, I went through Aaron Cake's writeup.
Old 09-05-12, 02:11 AM
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Is the connector secure in the alternator?
How is the belt tension?
Autozone will test your alternator for free.
If the first 2 are ok,then you may have a dead alternator and should get it replaced.
Old 09-05-12, 07:45 PM
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Yes
Tight
Its brand new.

just found a loose wire at the starter, but the car will not start now.
Deflood??? it was making a good amount of white smoke earlier when it was running.
Old 09-05-12, 07:48 PM
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to clarify "will not start"- it was cranking like hell but wouldnt start... wore the battery down.
Old 09-05-12, 09:21 PM
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I've had a situation like that a couple times where the engine would flood. The engine would crank but wouldn't start. Sounded like it was trying, though. This might not be a kosher way of doing things, but I took out the injector fuse and cranked the engine for about a minute and a half (have a buddy drive over and keep some jumper cables handy just incase.) This cleared out the engine enough for it to stutter back to life with the fuse back in place. The engine will sound pissed when it first starts up, but it'll smooth out within a few seconds.

I don't know about the light issue. Hopes this helps out with your starting issue, though.
Old 09-06-12, 05:59 AM
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Thanks, I like the sound of that. I may end up cleaning the sparkplugs as well. It's an S5 too, so I can peg the throttle to cut the pump and crank it without the plugs in.
Old 09-06-12, 08:36 PM
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Originally Posted by Phauss
I've had a situation like that a couple times where the engine would flood. The engine would crank but wouldn't start. Sounded like it was trying, though. This might not be a kosher way of doing things, but I took out the injector fuse and cranked the engine for about a minute and a half (have a buddy drive over and keep some jumper cables handy just incase.) This cleared out the engine enough for it to stutter back to life with the fuse back in place. The engine will sound pissed when it first starts up, but it'll smooth out within a few seconds.

I don't know about the light issue. Hopes this helps out with your starting issue, though.
I did a similar thing; took out the injector fuse, then had a friend tow me while I let the clutch out and made the towing car spin the engine. got it started in just a few yards that way.

Later, I wired a switch under my dash that would open the injector circuit to address the flooding problem on an older engine. worked pretty well until I could get an overhaul
Old 09-07-12, 04:55 AM
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I just started having this problem.
Basically I was driving around testing the sound of the new RB header and silencer I just installed.

Suddenly noticed how bright my headlights and IC was. Checked voltage and it had jumped to 16V.

Drove it home trying to keep revs/voltage down. On the way home I burned out a headlight and most of my idiot lights came on. The only ones that are off while the car is running are the Check Engine, Security, Air Bag, and Brake lights.

Everything else seems fine, its starts, runs and drove ok. The battery isn't bulging or anything from the overcharging. I checked the voltage off the White/Black wire on the the alternator connector. It reads about 5.65V, I read on here its is supposed to be between 1-3V. I am assuming this is a bad voltage regulator? or could it be a wiring/ground problem?

Also I have no idea what to do about the idiot lights as they are all on even when the car is idling and the voltage is only about 14V.

Last edited by k4killer; 09-07-12 at 05:18 AM.
Old 09-07-12, 07:54 AM
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Originally Posted by k4killer
I just started having this problem.
Basically I was driving around testing the sound of the new RB header and silencer I just installed.

Suddenly noticed how bright my headlights and IC was. Checked voltage and it had jumped to 16V.

Drove it home trying to keep revs/voltage down. On the way home I burned out a headlight and most of my idiot lights came on. The only ones that are off while the car is running are the Check Engine, Security, Air Bag, and Brake lights.

Everything else seems fine, its starts, runs and drove ok. The battery isn't bulging or anything from the overcharging. I checked the voltage off the White/Black wire on the the alternator connector. It reads about 5.65V, I read on here its is supposed to be between 1-3V. I am assuming this is a bad voltage regulator? or could it be a wiring/ground problem?

Also I have no idea what to do about the idiot lights as they are all on even when the car is idling and the voltage is only about 14V.
And the B/W wire in the same plug as the W/B wire should be 12 volts w/key to on. You are correct to say the regulator is problematic.
Old 09-08-12, 01:15 AM
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OK so! New battery... new plugs, alternator has been tested and verified good. Put it all back together, and started up. 14.3 volts while the car warmed up. Idiot cluster is working fine.
Problem- Voltage is great, until the engine has been warm for a minute or so. The voltage dropped when the engine calmed down from its cold start, but the volts would come up when I revved, up to 14.6 around 6 or 7K RPM but no higher. So I said screw it, I need to put gas in it. So on the way to get gas, the volts stopped responding to RPM and settled around 12V. Any ideas as to what I should do? I'm thinking replace some cables. Anyone agree? Seems to me some wire is getting hot and causing impedance/resistance. Where exactly does the wire from the output of the alternator go to???
Old 09-08-12, 01:27 AM
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Just thought of something... does the fact that I'm running a 130 amp taurus alternator with the stock charging cable have anything to do with this??? Makes my question about where the output wires go all that much more important... And actually, there are TWO wires on one terminal bolted to the output of the alternator. I really would like to know where they go, without someone being a smartass and posting a pic of a wiring diagram that more than half of us will stare at blankly and drool without learning a damn thing.


thanks! :-)
Old 09-08-12, 10:32 AM
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The output wire runs to the cable which comes off the back side of the engine fuse box. There is a cable connected to the Main fuse and it is this cable that the alternator connects to. And just because the alternator tested fine means very little if anything. And you might want to check the main ground for the battery that runs to the bottom of the fender strut tower.
Old 09-08-12, 02:13 PM
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Thanks satch, I re-did the grounds already, including that one. I guess I'll re-chase the threads with a tap and make double sure. I really think it's the cables at this point.

So the output of the alt goes to the engine fuse box... the 100 amp fuse. By the "back of" do you mean it connects to the shock tower side of the fuse? Where does it go from there?
Old 09-08-12, 02:19 PM
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After the shock tower it runs to the long starter bolt. The output wire connects to the cable coming off the rear of the engine fusebox.
Old 09-08-12, 05:22 PM
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Originally Posted by satch
After the shock tower it runs to the long starter bolt. The output wire connects to the cable coming off the rear of the engine fusebox.
the shock tower is a ground... you're confusing the **** out of me.
here... I'm sure you have Paint on your computer... This is the charging system as I know it. Feel free to edit and repost.

Name:  powerdiagram.jpg
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Old 09-08-12, 05:34 PM
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I goofed and was not paying attention, sorry. The cable which connects to the Main fuse (shock/strut tower side) drops below the fuse box and connects to a cable which runs to the Ignition Switch ( and splices into the output wire of the alternator as well) which also runs to the circuit breaker fuses at the interior fuse box.

The Ignition Switch does not have a wire running to the alternator on an S5 as per your diagram.

The Red line on the right side of your alt. diagram runs to a fuse at the engine fuse box that is powered by the battery so this is semi close to your depiction.

Last edited by satch; 09-08-12 at 06:01 PM.
Old 09-08-12, 11:12 PM
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Originally Posted by satch
The Ignition Switch does not have a wire running to the alternator on an S5 as per your diagram.

The Red line on the right side of your alt. diagram runs to a fuse at the engine fuse box that is powered by the battery so this is semi close to your depiction.
ok... one of the wires (besides the alternator's power output) is constantly supplied with 12V. The other is not. What does it do?
Old 09-08-12, 11:14 PM
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Also, what about the ? coming off the alternator's output?
Old 09-09-12, 01:28 AM
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Originally Posted by Riggs
ok... one of the wires (besides the alternator's power output) is constantly supplied with 12V. The other is not. What does it do?
It runs to the CPU where the alternator warning light relay is located. This is what causes the idiot lights to turn on w/key to on or when the alternator is failing.
Old 09-09-12, 01:32 AM
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Originally Posted by Riggs
Also, what about the ? coming off the alternator's output?
There shouldn't be two wires coming off of the alternator output terminal.
Old 09-09-12, 01:37 AM
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but there are.
Just took a dash to the gas station... same story, volts at startup rose and fell with RPM, but after a few minutes of warming, output was squashed to ~12V. Is this most likely due to old wires, or something else?
Old 09-09-12, 01:59 AM
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There should only be three wires total. One is output, another goes to the CPU and the third wire receives constant voltage source at the engine fuse box. Some will take the wire that receives constant voltage and run it to the output terminal but that still only leaves three wires in total.If you have four wires connected to your alternator then I am not familiar w/that wiring method. Again, an alternator can pass a test at the auto shop but still be faulty as this happens fairly routinely. And your problem screams "voltage regulator." It's possible your voltage gauge is inaccurate but all you would have to do is to test the voltage at the output terminal w/a meter.

Last edited by satch; 09-09-12 at 02:18 AM.
Old 09-09-12, 09:09 AM
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Ok. for whatever reason, I have two wires going to the output of my alternator. Both on one ring terminal mind you, but two wires all the same. I will swap them out with one 4GA wire to the main fuse.
Old 09-09-12, 09:40 AM
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The question is where are they coming from. If one is coming from the back of the alternator then that would mean you have three wires connected to your alternator, correct? Or do you have four distinct wires connected to your alternator and if is so are you completely sure it is an S5 alternator or from a non RX7?
Old 09-09-12, 11:50 AM
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Taurus alt, homie! It's in my signature lol.

the wiring is stock though, two wires on the controlling end of the alt, and what looks like a factory setup to go to the output of the alternator that has two wires crimped to the same ring terminal. One goes to the engine bay fuse box like my diagram, the other I have no idea. So yeah, 4 wires total, but only two are discrete. It's as though someone wanted to split the output of the alternator to two different places. I just have to figure out where the second place is. Or maybe I'll just not bother. I'll set it up with the one wire and see what's what.
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