I have a 2k2 6spd and it has plenty of work done. For some reason my car won't idle higher then 12.9 and i see it often between 12.4 and 12.9. My battery is in my trunk and i'm running 0 gauge from the little relay box/wire that normally connects to the positive part on the battery and running a 0 gauge wire to my trunk along with a 0gauge ground going to my rear strut. It measures the same voltage at the battery, the connection, and even the alternator.

I replaced the belts first, no difference except now something ticks in that area, i replaced the alternator with a new oem alternator from someone here and it idled a bit higher (ex: high 12's and lights dont dim as much but still dim)

what am I missing? I have no audio work, i have led's in my doors and a wideband that's hooked up but doesn't work. Battery is in my trunk due to the custom turbo setup. plus, my car randomly dies while idling and im not sure if its because of voltage, maf, or something else.

SUMMARY:
Low voltage even after new alternator and belts, randomly dies, battery is in the trunk, car is turbod, no other electrical/audio mods. why?

 

Start with the easiest place, the battery. Have it tested.

 

What does it do at higher rpm ?

 

I had it tested before and it was ok. The battery stayed at about 12.4-.5 I put my other cars battery in too with basically same voltage, that battery always ran my Avalon without s problem but AutoZone said "its on its way out" ill try and get a friend to rev it so I can measure. Silly electronic Tb

 

When was the last time the car was running fine with proper voltage?
What changes have you made since then?

 

The car died out of nowhere a few weeks ago. So I jumped the car, took the battery to AutoZone and they said it was ok. So I did the drive belts and crank sensor then the ticking / knock came up and the car randomly shuts off at times, so I replaced the alternator and idler pulley. Still ticks and still low voltage. I'm wondering if its my timing chain tensioner making the sound or if I over tightened the drive belts.

 

Have you tried testing it with a different multimeter

 

Nope but my battery doesn't charge and I usually need a jump

 

There is a 10 amp fuse in the fuseblock by the battery. The cover labels it ALT.S (iirc). This supplies power to the alternator windings. If it's blown, the alternator won't charge but would test good out of the car. Similiarly, the wire that carries the power from this fuse to the alternator, the little 2 wire plug on the alternator, could have a problem. A few guys on the org have found the lock clip damaged and the plug would not stay seated all the way.

 

This is absolutely vital info that you should have mentioned at the beginning wtf lol.

You are diagnosing for a no-charge issue then. Needs to be tested in the car

 

lol lord

 

as in the alternator or car must not be charging it, yet when i had the same battery in my avalon it was fine. and that's with an alternator from 1997 with 190k miles lol, the battery takes a charge, and the one that's normally in the maxima was bought in june, everything has been tested in the car. at autozone they said they couldn't test the alternator while it was in the car because the battery wasn't fully charged, well wtf why isn't the battery fully charged yet it tests good. the car drives fine if i leave the battery on a charger over night for like a week or 2 but then i may randomly need a jump and that's when i read the voltage. and that's when i read the 12.4-12.8/9 at all areas.

the plug on the alternator stays on fine, theres only the main wire and the clip iirc. i'll check that fuse. i didn't even think of checking fuses.

also - when i disconnect the negative terminal while the car is running it stays running for a few minutes then shuts off.

 

I don't think you understand my post bro. I said nothing about your battery. I said you need to diagnose for a NO CHARGE issue.

Google it.

Give ur head a slight shake....of course advance auto can't PROPERLY test it. Take the car to a ****ing garage where it can be A.V.R. Tested. Lmao. Still need to know what it does at higher rpm

 

fully charged the battery last night, took the car for a drive and to a meet today. when i got home the car was idling again at 12.4-12.6 at 2k rpm it was at 12.7 at 2500 12.75 and 3k 12.8 and 3500 12.8 i'll give it a shot tuesday to find a garage. class all day tomorrow =[

 

Sounds to me like the alternator is bad, or the connections to/from the alternator are bad.

 

if that's the case i'll be really upset with the seller who sold me this "brand new oem alternator" the symptoms are the same as my 143k alternator vs this one. the new one maybe put out a little more like .2 or .3 if that.

do we have external regulators or anything? possibly other fuses or relays? I checked the Alt.s fuse someone posted above about, that's fine. the clip is also in the alternator fine and the main wire is tightened down as well.

could bad grounds somewhere cause this? the alternator must be putting out some power considering i just started the car and before i started the battery was at 12.4 but while it was running it was 12.5-12.7 but that's not enough to keep a battery charged =/ i really can't keep putting a spare battery on the charger to drive the car for a day.. it's getting kinda bad now

 

I was talking to a few friends and this is what we are also thinking/wondering:

My utec may be messing with my ecu somehow and not telling alt to fully charge, has anyone had this problem?

A few weeks ago just as my battery first died the car would give me a baby shock once in a while. It hasn't since though. Possibly a bad ground? I since then went to a bigger ground for the battery in back attached to my rear drivers strut tower.

 

This car sounds like it has an underdrive pulley!!!!! Is that ground wire against bare metal! Why not mount your ground else where to the frame but clean it off and use star washers!

 

The voltage regulator is built into the alternator. You can still replace the voltage regulator, but you have to take the alternator apart. Not many places sell the voltage regulator.

The ECU has nothing to do with telling the alternator to charge. That is done by the voltage regulator inside the alternator. I'm gonna stick my neck out and say that your ground is probably ok for the interior electrical items. But I think you really should have a cable that also goes up front from the battery and bolts on to the engine.

 

frame ground FTW

 

Stock crank pulley. Is it possible my drive belts are too tight? I know they're not loose. I don't see that causing low voltage.

My battery is in my trunk and I always heard shorter grounds are better. It's ground to the rear strut tower that is bare metal. I can go over the small OEM grounds to make sure they're connected and grounded right but I never messed with those.

I took the car to 2 shops and they said they won't bother testing it its either a short somewhere or the alt is bad, this is a new alt but its from a seller here.

Second battery died again today. I just put it back on the charger to get me to work tonight. I have had the batteries tested, they were fine. They just cant fully charge at 12.5 volts

One more thought, could crank sensors play a role? This happened a similar time from when I changed it.

 

Upgrade the grounds:

From Engine Intake Manifold to Chassis
From Alternator to Chassis
From Transmission Bellhousing/Block to chassis
Ensure they're all secure, use minimum 8 AWG wire, and are all contacting flat, bare, degreased surfaces.

ONLY USE FLAT WASHERS and torque the bolts properly.

The above should all but eliminate the potential for grounds to be causing this.

How is your Battery wired in? I have to assume that's the problem. There should be a 'charge' wire that comes from the alternator to the battery. This is also the 'sensing' wire for voltage regulation (turning the alternator on/off).

Again, how did you wire it in? Go into detail, because again, that's probably the issue.

IF it's wired properly, then you need to go through every connection in that main Power Circuit one at a time checking voltages, write them down. This will be usefull later for voltage drop calculations.
Then remove, clean, and thoroughly inspect every connection.

 

I'm going to check over all these grounds now to make sure none have grease or are loose, i have a feeling theres something with my intake mani ground or possibly the ground that attaches to the bracket on the alternator. All these grounds are still the OEM wires so i'm not sure what gauge those are. I'll upgrade the easier ones with whatever 4-8gauge wire I have laying around. At this time I'll also take pics of where the battery is wired, it may be easier then simply describing. I have work in a hour so i'll update this later tonight.

small update from previous posts: I disconnected all extra wiring i had, so i took out the wideband wiring and took a ground i had laying around behind the radio from an old aftermarket (oem is back in there and wiring looks to be good) I also regrounded the utec to the small frame piece behind the glove box (where the glove box bolts into) the car started much easier, but still idled at only 12.5-12.6 volts. I disconnected the negative on the battery and the car still ran with no problem. It idled the same 12.5 volts and when the fan turned on it idled at about 12.2. This is without the battery connected at all, so therefore the alternator is powering the car, just not enough.

Like i said above, i'll update later tonight with pictures of connections and let you know how the grounds look. I do remember the trans to frame bracket is starting to rust or get surface rust. i'll redo that now. I only have an hour before work

also, huge thanks to you guys for helping me out so far.

 

Tuner had it, I went over the grounds and I wasn't happy with the rusty bracket and I only had 12gauge wire laying around so I added that along with the OEM one and when I went to find the ground for the intake mani I couldn't find anything so I took more 12gauge and bolted it to the back of the intake to my strut tower. Start the car and it fired without a problem and idled at 14.1at the front and 13.95 - 14 in back at the battery

Thursday I'm going to remount the battery and bolt it down better and redo those grounds with the right ends and 4gauge (if I can't find 4gauge ill do 8) the 12ga speaker wire was just to test it out. When you say alt ground, should I ground the case or is there a different one somewhere?

Now to hunt down the ticking / knocking sound by the drive belts. Ever since I did the drive belt there's a ticking like a tensioner or something. I don't think its my timing since it was fine before I did the belts. If I can't figure it out by next week ill make a new thread.

Thanks again everyone and especially to tuner for pointing out those main grounds.

 

Good to hear! glad you got it sorted. might be prudent to continue the search (if you didn't check ALL connections), just to ensure no future head-scratchers!

Not sure how we all kind of overlooked the relocated battery, once I clued into that it was kind of obvious that that's the most likely cause. Anytime you move a battery into the trunk, especially in a uni-body car, you need to upgrade the engine grounds, everywhere. The current has to travel through the entire car chassis now, not just through the engine bay/firewall area like it did before. This explains you getting shocked also.

Running a large Ground cable from the battery to the front of the car would sort this out much better, but that's crappy on the wallet and isn't necessary as long as you spend the time/money upgrading all the grounds and ensuring you've got thick, solid steel everywhere you ground.