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1ZZ-FE Charging System Question

5K views 32 replies 9 participants last post by  bubbah16 
#1 ·
My Matrix is running great now that I fixed my injector seals and got the fuel trims back where they needed to be, but I'm still having a vibration issue at idle.

I noticed today that when I roll the windows up, or the cooling fan kick on the car dims and idle lower and vibrates.
If you give it the slightest bit of gas it will go back to perfect.

I have an outlet plug that has a voltage meter on it and at the socket it reads 13.9V while cruising around with AC off and around 13.4V with AC on (goes back to 13.9V if I really get on it).

At idle it reads 13.6V without anything on, but once the air and fans kick on it will go as low as 12.1V.

Every time the voltage goes down it vibrates like a misfire.

I had the battery and the alternator tested at my local part store and they both passed but i do not think it was tested correctly myself.

Battery voltage is about 12.4V with engine off

Any suggestions?
 
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#12 · (Edited)
Skip to the end of you want simple



Until post 5 it seemed like a good theory...

Be sure to check the positive side for the same problem as well.

Generally, a new alternator would fix this issue, but I always do voltage drop tests before I replace an alternator to be certain.

Check for voltage from one end of the negative cable to the other end. Yes, that's right, you're not putting it on positive and negative, just on the negative. If you find voltage, it's how much voltage is lost across that length of wire.

This can find voltage loss from a terminal to the battery post, to it's post, on the positive wire - any wire that you suspect has excessive resistance. If none of these issues exist, the problem should be the alternator.

Sure, it could be a voltage regulation issue, but that's still in the alternator, right?

Rule out bad wiring ...if it's good, it should be the alternator. Furthermore, below are much less likely issues:

1. You could have a component turn on at higher loads which has a high drain on the system that it should (unlikely, but could be possible)
2. Why would the wiring suddenly be bad with a little more voltage?
If it's just that there's just enough resistance at low rpm to not look like a problem, but then it is at a higher RPM, and thus more amperage...would it suddenly lose so much voltage? Seems most like an internal alternator issue, where as you demand more out of the stator it hits resistance.

Edit: To put it very short. I don't think your alternator keeps up with more load. Bad alternator, most likely end of story, but still check your wires for voltage drop as described above so you have a very healthy electrical system when your said and done.
 
#6 ·
Check alt voltage, with load ( ac/fan), directly at the alt terminal and compare to voltage at the battery post.
A v drop greater than a tenth or so across the positive side of charging circuit, suspect high resistance in connections/cables.

Additionally if battery voltage drops below 10v while cranking probably on its way out especially if 3-4 years old.
 
#15 ·
Correct



And when you're done do the same on the positive cable to the battery to the starter. Should be negligible voltage.

I did think of one more possible cause.

Your fans could be drawing way more energy than they should. You can check these wires similarly. Or even feel them for being hotter than other wires (if that's the problem you could burn yourself).

I love my laser guided infrared thermometer from Harbor Freight. On sale for only $17.99. Dang. I wrote that like an ad, lol.

For example, the other day my Nissan Frontier had a hard time starting. The only tool I had on me at the time was that touchless thermometer. So, once it was running, I started poking around at the temperature of things.

I realized that the no. 1 spark plug wire was much hotter than the other ones! I bought a whole set, but I only replaced the bad one (sometimes I've gone as much as 7 years after a first wire needing replacement to the last one needing replacing).

The easy way is an expensive flir, or some other infrared camera so you can look for hot spots. For example, in your fuse box if something is running hot or with high resistance, the temperature can be spotted there.

This is easier than buying a $50-80 voltmeter that can also read high amps like a normal working fan (above a standard voltmeter's limit of 10 amps), let alone one that may be, or the wiring to it, is going bad.

I might feel like I live for compliments after yours today. Feed me one, and I'll tell you 3 more ways to skin the same cat. :) lol
 
#16 ·
That test looks just lovely. Still do more testing...seems more like a going out fan than wiring to and from the battery, but I'd still check the wires to the battery with the voltage drop testing you've learned about just because it's easy, and because I've seen the voltage drop test show a problem even when that fancy tool missed it.

You see, when you're starting the car, I believe a lot of other systems are temporarily down so all the load is just the starter and necessary electronics, which in a diagnostic series of test I've seen before, meant the issue was elsewhere. (stuff like fans that aren't on while starting a car).

Sorry, super long sentence. I'll try a smaller chunk. I have seen before that a startup test like yours looked great, but there was still another component having a high draw on the system when it activated.

It's a little harder until you've had practice then the voltage drop testing around the battery, but you can do the same from the fuse box for the fan, to the fan (takes a lot of length of wire), check on the the health of the wires from the fans relay, without every looking up a wiring diagram (well, you'll probably have to learn a bit before you can do it without a diagram).

Anyway, Schordingers Box on YouTube has done a lot of thorough electrical testing with a very similar situation to yours - I'm sure it's not on a Toyota, but the testing concepts are the same.

Again, heat vision or a touchless thermometer could help you narrow it down to which wire needs testing....unless of course it's just the fan motor itself (comes up across all makes and models).
 
#19 ·
Ya something is bogus about the testing prcedure...

again no load value is shown...

Using google I found a prinout from the same testing apparatus... notice how on the charging test there are values for the load/no load amperage... the OP's load/no load values are left BLANK... indicating it wasnt tested..

 
#20 ·
When testing, all the guy said do was run the car to around 2000 RPMs with nothing extra on, then up to 2000 RPMs with heat wide open and headlights on.

At home I can put the car in drive, hold brake, turn on heat, radio, power outlet, interior lights, and fog lights and it reads down to 11.2V at idle.

As soon as I give it throttle it shoots right back up around 13.2V.
 
#24 ·
That is not good at all. I'm gonna guess that alternator is bad. What is the idle at when all those loads are on?
 
#26 ·
I think it's a pretty safe bet your alternator is bad.

Have you done the voltage check directly from the alternator output terminal and a voltage drop test of the cable?
 
#30 ·
Use your multimeter and check voltage from the alternator stud to ground. If it's the same, your alternator is probably bad.

The tensioner is automatic so it should be pretty easy to tell if the belt is loose or not, it's most likely not.
 
#32 ·
I have noticed that the reason the car idles rough and voltage drops when warm up is because the cooling fans coming on.

I assume its a factory thing that when the car is running and still cold the fans will kick on if the defroster is on (even without the A/C button turned on).

When the car is warming up from a cold start it will idle around 1000RPMs but as soon as I turn the blower motor on to turn on defrost it drops to 725-750RPM immediately.

Going to get another alternator and see what happens.
 
#33 ·
charging problem too

Happened today comming back from Mtl, in cluster battery lights up and flashes while at 100Kph,
heater was on and radio. It did it for about 30 minutes.

At one point it stayed on for 3-4minutes and it slowly faded away as I sped up to 120with no accessories.

Upon opening hood there was battery corrosion on both poles wich could be indication of undercharging and overcharging (positive).

I had the belt tensioner (oem) replaced about 2 months ago before the cold really kicked-in.

Will check the belt tension between the tensioner and alternator pulley.

Q- Wondering if the replacement of old tensioner/Toyota belt to new oem tensioner/Gatorbelt might have something to do with alternator charging problems today?
 
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