only 13V at idle without system playing, could it be new timing belt?

[thegreatestpenn 5,000+ posts]

So about a week ago, i took my civic in for service and they changed all my belts, including the belt for the alt. Today while i as playing my system at full tilt (i rarely do so I was checking voltage) i noticed my voltmeter reading upper 11.xxx to low 12.xxx. I thought it strange so I paused the system and the voltage only got up to the upper 12.xxx. So I'm thinking the voltmeter might be bad, or my 2nd batt's ground. So when I get home I check the voltage, come to find out the car is only charging to 13V at idle with no electrical accessories on nor the sound system (in my sig if you're wondering). This has me puzzled, I used to always idle at 14.5V give or take .2V. Could the belt they put on be an improper size causing the alt not to charge higher? all help is appreciated.

I also cleaned the batt terminals up front to make sure they didn't have corrosion causing the problem.

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[weffy 10+ year member]

It could be a bad connection wherever you checked the voltage?

Also, places like autozone and advance would check your battery and alternator for you with this big expensive dmm.

Where did you check the voltage? Check it at both batteries, and at the alternator would be my best advice to figure it out.

 

[Ali1 10+ year member]

is the alternator a HO alt? If so, which company? I had a similar situation with my EA alt

 

[weffy 10+ year member]

I think HO alts are more than often a complete waste of time. Theres always problems with them, and most of the time they're just regular alternators over-rated. I do know that they have good, legit ones, but I'd be too nervous about getting screwed to ever buy one.

I just stuck a junkyard alternator on my a/c compressor bracket, and know for-shure that I am getting 105 amps just to my subs, and the highs are on the stock 90amp. A 200 amp system for about $50 (new belt, $20 alternator, bolts), not bad.

 

[shizzzon 10+ year member]

well, first off, u cant charge batts at 13v or lower so u need to not use anything unnecessarily for the time being.

Now, start up the car and measure voltage with dmm at the alternator itself.

If it's reading very low then go ahead and shut the car off.

Check tension on the belt to ensure it's very tight.

Measure voltage with the car off. If it's the same voltage as the car on.... is your alternator even working?

It's not safe to drive without an alt if u do not have a battery charger...

Another thing- disconnect ALL extra batteries leaving the starting battery as the only battery connected.

It's possible if you have a bad battery, bad cell or a mixture of battery brands that rest at different voltages to try to "level" the voltage between all batteries in the car. When this happens, the alt tries to stay charging all the time which will drop the regulator down LOW.

 

[audioatg 10+ year member]

well, first off, u cant charge batts at 13v or lower so u need to not use anything unnecessarily for the time being..

Guess you an old school tech. Alot of cars in todays market you will see charging at 13 volts. Around it not saying at 13 volts. But it does not always have to be at 14 volts.

To the OP you said they just changed your belts. Im betting on they did not tighten them up good enough. And it is causing some slipping of the blets.

 

[thegreatestpenn 5,000+ posts]

its the alternator, when I went to bw3, my first voltage was 13.5V by the time I got there it was down to 12.12V. alternator number 3 coming up :/

 

[shizzzon 10+ year member]

Guess you an old school tech. Alot of cars in todays market you will see charging at 13 volts. Around it not saying at 13 volts. But it does not always have to be at 14 volts.
To the OP you said they just changed your belts. Im betting on they did not tighten them up good enough. And it is causing some slipping of the blets.

No... newer cars today charge around 13.8v, not 13v

You can charge a battery AT 13v if it's extremely low but once it starts getting charged.. it will only go so far until it stops receiving a charge and the voltage will need to be increased if you want to continue.

The OP clearly stated charging at only 13v at idle and lower... That's not typical.

 

[audioatg 10+ year member]

No... newer cars today charge around 13.8v, not 13v
You can charge a battery AT 13v if it's extremely low but once it starts getting charged.. it will only go so far until it stops receiving a charge and the voltage will need to be increased if you want to continue.

The OP clearly stated charging at only 13v at idle and lower... That's not typical.

You should take a peak at some tech specs on some of the newer cars out today. Been doing PDI's on newer Kia cars and its **** low voltage for my taste right around 13 volts all the time. Seen 13.4 13.6. Thats low and its normal for them.

I seen what the OP said. didnt think anything about it though being I seen cars doing that before. I also seen the part about when was always charging at 14 plus volts.... Keep in mine buddy. We are not with the guy. and We are not there to do any tests. Just like in the car section of this forum. We are only giving guesses as to what it is and some helpfull tests.

If anything to the OP dont take it to that shop anymore. I know my shop wouldnt of missed it. We have to check charging voltage before and after we changing belts on cars like yours. We even use a belt tension tool.

 

[thegreatestpenn 5,000+ posts]

it wasn't a shop it was the dealer. the alt was used and 4 years old getting abused by my various stereo setups. I think its time was up. my first went out after around 4 years as well so this is about right. already ordered another, but my lazy butt isn't putting this one on

 

[audioatg 10+ year member]

it wasn't a shop it was the dealer. the alt was used and 4 years old getting abused by my various stereo setups. I think its time was up. my first went out after around 4 years as well so this is about right. already ordered another, but my lazy butt isn't putting this one on

Why didnt you say it was four years old lol. I did go off topic though a tad bit that was my fault. Even a dealer they should of seen that. I havent had mine alt that long enough running to see the voltage tank. But the bearings in it have gone bad a few times. Well they just made some bearing noise never locked up.

Did you ever have that problem with your alt. Bearings.

 

[thegreatestpenn 5,000+ posts]

okay update. the alt's not blown, checked voltage at the alt and it was higher than at the battery. but its not the battery either, the battery and alt passed a load test. So I was trying to figure out what wired to the batt was causing the drop in voltage. Turned out to be the stock wiring. When I took off the alt to batt wire from the post it would read the alt's voltage of 14.4V or whatever. if i stuck it back on the batt, it would immediately drop down to 12V or whatever the batt was reading. Then i removed the alt to batt and power wire for the system and attached them together and they still read the alt's voltage while the battery and stock wiring read the lower voltage. So my only conclusion is that the stock wiring is screwed up or something is causing a drain when the car is on. Any suggestions on why this might be?

 

[Carnivorous18 10+ year member]

Have you upgraded the big 3?

 

[thegreatestpenn 5,000+ posts]

yes and i checked the 1/0 ground, still was reading normal. alt to batt wire was fine as well

 

[jdawg 5,000+ posts]

well it will increas if you take off the alt to batt wire, you are taking a huge load off the alt, the battery, or did you mean you took off the STOCK alt to batt wire and left on the 1/0 alt to batt wire?