Good morning Fit Freak brethren.

Although there are many threads within these forums on battery replacement, I have not found (not saying it doesn't exit) a good thread instructing on how to properly check alternator function in order to make sure my car battery is receiving enough charging and that the alternator is not failing.

Any guidance, how to, procedure you can point to is appreciated.

Note: I am really looking to discover a "quick check" on the alternator with a multi-meter or the such.

-Slopster of Snoodingtonham

 

A simple voltage test is the easiest. It should be 13something to 14something. This should be with some load (i.e. headlights on) with increased RPM as the electrical load sensor turns off the alternator when there's not much electricity being used.

I'll check the shop manual later, but the honda procedure may be too complex to be practical for DIY and just a multimeter.

A full test would mean loading the alternator up to its capacity rating and watching the voltage at some specific RPM, and a separate diode test. This isn't something you can do with a multimeter. If the battery is in bad shape, this will skew the results. A good/charged battery is really needed to perform this test.

 

Thank you Steve.

I think I remembered you replying to someone else's thread a while back about the alternator/battery on our Fits.

If the following is the correct section from the service manual, I take it that 13.5V to 15.1V at the alternator with the engine at 2,000 rpm and a 60AMP reading is a pretty good indicator of alternator condition?

LINK: Alternator and Regulator Circuit Troubleshooting (Click Here)

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Damn you're good.

Yeah that's it. Except without a more sophisticated starter/charger/battery tester the voltmeter check in step 5 is all you can do... no way to load it to 60+ amps.

 

Thanks Steve. Stay thristy my friend.

 

.... the charging light flickered on 2-3 times in the past 3 days when wifey-pooh got on the accelerator hard on the on-ramps. Tightened the terminals (with terminal shims) a bit and now the charging light stays on.

Off to Auto-Zone/O'Reilly's for a battery/alternator check. Will report back.

 

Here is what I use

 

UPDATE: While Honda supposedly charged the battery and inspected the charging system ("good" they said), I was unhappy to find the battery drained to again when the Fit made the 50 mile trek home. Re-checked all electrical connections and cleaned the metal on the chasis grounding point and the grounding strap off the battery's negative terminal (charging light flashing on for a brief second then gone again).

Decided to drive up to the O'Reillys 10 miles away (started and ran) for a test run and free battery/alternator check. On the drive to O'Reilly's, I noticed that if the engine was reved above 3,500 rpm and all the way up to 6,000 rpm, an abrupt "left off" of the accelerator caused the car to lunge slightly and flicker the charging system indicator lamp. Repeated the observation 7-8 times.

Once at O'Reilly's, the battery tested good but only at 13% charge capacity (apparently the Fit was running off the battery most of the way home and to O'Reilly's).
After checking and charging the new 51R battery I installed, the sale rep. checked the charging system and the alternator function. Viola!

ALT --> LOW voltage (11.4V at idle 13.0V at 2000 rpm)
Diodes --> Good
Generator Output --> LOW

So much for Honda's electrical analysis and testing (Avon, IN Honda stealership). I stopped by this morning and let the shop manager know what I thought about their diagnostic procedure for my wife's Fit problem and left. No charge. LOL.

Pissed off, I went ahead and placed an order at partsgeek.com or a A3410 USA Industries remanufactured alternator ($122 + $80 core) and a new serpentine belt. The Fit is in the garage for a few more days and we had to opt for the rental car this week (Chrysler garbage).

I will update as the alternator and belt arrive and installation occurs. Fook. Hopefully the system will be repaired soon.

***Reman alternator and belt arrive via FedEx Thursday, 23-JAN-2014 FedEx tracking says). Hope so.

 

UPDATE: 26-JAN-2014

Alrighty!.... Installed the new U.S. Industries A3410 remanufactured alternator and Gates K050448 serpentine drive belt in my 2010 Fit (base) with little drama. Pretty simple 45 minute job but do remember how the serpentine belt is routed before you take the belt off.

Alternator Installation Notes:

1. SAFETY!: Disconnect the negative ground from the battery terminal before you ever touch an alternator with any tool.

2. Replacement alternator is much easier to install on 2009+ model years. Alternator can be completely removed and accessed from the top of the engine bay (no EGR removal nor EGR valve mounting stud removal; no radiator fan removal; no windshield washer fluid reservoir removal <-- items necessary on 2008 and earlier Fits)

3. Rubber AC line has adequate "play" for sliding the old alternator out of the engine bay and the new alternator into the engine bay for mounting. Just take it slow and easy "navigating" the part in and out.

4. Alternator mounting bolts are 12mm. Use deep well 12mm to reach the lower bolt from the side near the exhaust manifold. Standard 12mm socket for the top bolt.

5. It is much easier to unscrew the wire harness metal plate first (8mm head) in order to push the plastic clip out of the mounting hole and to loosen the alternator's main power cable (10mm nut) for disconnection.

Post-Installation Voltage Readings (Craftsman Multi-Meter)

Battery (Engine Off) ------------------> 13.2 V
Alternator (engine Off) ----------------> 13.2 V

Battery (Engine at Idle)---------------> 14.5 V
Alternator (Engine at Idle)-------------> 14.5 V

Battery (Engine at 2,000 rpm)---------> 14.6 V (rear defrost on, hi beams on; AC on; radio on)
Alternator (Engine at 2,000 rpm)------> 14.6 V (rear defrost on, hi beams on; AC on; radio on)

Observations and Corn-clusions

Road test runs show no charging system CEL lamps coming on "solid" or flickering/flashing on after reving to 3,500 rpm + and letting off the accelerator. Voltages all check out as "good." No whining or noise from alternator or the new serpentine drive belt installed. Of note, under load of everything electrical turned on, the previous "dimming of the headlights" that occurred when the auxillary electrical cooling fan activated is no more. This further supports the voltage regulator in my original alternator beginning/continuing to fail until the OEM battery could no longer support electrical demands.

After a U.S. Industries A3410 remanufactured alternator ($122 @ PartsGeek(dot)kom), Kirkland Signature 51R battery 500CCA ($70 @ Costco), and Gates K050448 serpentine drive belt ($18 @ PartsGeek(dot)kom) replacement, it appears that my charging system has been returned to good working order. $210 parts and about 2 hours total labor & diagnostics (self). Sloppy is happy with the Fit again.

 

I think you mentioned you're at 145K? Sounds like a righteous fix.

This place needs better smilies...

 

Checked the odometer again: 142,000 U.S. miles (and some change).
Thanks Steve. Snoop Dogg called my repair the shizzle. (...really, he did! This is the internet so this is the "truth" LOL).
Theeze dhayzze... uze gawt two brink yer owen smye-Lees....

 

In your opinion, could a failing alternator cause a battery to drain while sitting off for 3-4 days? I'm having an issue with my Fit where I have to jump the car if it sits too long. Battery is fairly new, tested ok. The Autozone guy tested the alternator and said it might be outputting a little lower than it should, but if it was really bad obviously it wouldn't keep the battery charged.

Trying to avoid expensive electrical diagnosis..

 

Folks that try to "avoid expensive ... diagnosis" can end up paying even more as they try to guess their way to a solution for a problem they don't know.

Can the alternator be bad, running low? maybe.

Can the battery be bad, despite being "fairly new"? maybe.

Can you have something ON, that shouldn't be? maybe.

Can you have a short in the wiring causing the slow drain? maybe.

Too many maybes.

 

Although it may seem like it does, a failing alternator itself will not cause the battery to drain.

When the output of the alternator is in decline, there comes a point in time when there is inadequate charging from the alternator back to the battery. Two things begin to happen:

1.) the battery is slowly charged slightly less than it should be during each use (this is hard on a battery and actually deteriorates the battery's ability to hold charge over time; the longer this situation exists, the worse the situation gets). This is even more ponounced if there is more than one diode failing within the alternator.

2.) a battery receiving inadequate charge will "work" (start the car, etc.) as long as the battery maintains a minimum operating voltage. Where this gets "hairy" is when the weather turns cold (my original situation was just like this) and the battery's charge capacity is decreased due to temperature (all lead/acid batteries operate in this manner).

Odds are that the alternator is on its way out. Aside from some short somewhere on the wiring, there is not much to a charging system... unfortunately, if a failing alternator is allowed to undercharge a new battery during vehicle use, it will cause the battery to lower its capacity and ability to hold charge over time and toof the battery before its 3-5 life cycle prematurely.

What to do?

I would simply recommend you charge the battery with an external charger to capacity and drive it for a short period of time and re-check the battery's voltage before and after use. Check it again the next day after use. If the battery fails to charge back up to 13+ Volts and the alternator at 2000 RPM isn't between 13.5 Volts and 15.1 Volts, replace the alternator.

Considering there are only 3 main components in most car's electrical charging system, it should be rather easy to determine which component is the culprit. Well within the home mechanics capability IMO (considering that AutoZone, O'Reillys, NAPA, will all test the system for you for free).

Shorts, bad batterys from the store are definitely possibilities but those occur less frequently than just a failing alternator. All a dealer is going to do is charge the battery up for you and hand the Fit back to you. Your own answering of Goober's "maybe's" will be more apt to repair the problem than a dealer. A dealer couldn't diagnose an electrical short if the dealership's life depended on it. IF you believe a short exists in an automobile at all, let a dedicated "auto electric shop" check it over (usually around $100 though for the service).

 

Get yourself a battery voltage monitor and plug it into the accessory plug of your car. Watch the voltage and see what is going on. Cheap ones can be had for $3.00 out of China from aliexpress.com or a good one is less that $15.00. Without out it you are just guessing. Walmart use to have them in the automotive dept. I have not looked recently to see if they still do.

Equus Innova 3721 Battery Charging System Monitor - Walmart.com

12V/24V High Bright LED Display Mini LCD Digital Car Battery Voltage Meter Monitor Tester Voltmeter Gauge -in Voltage Meters from Industry & Business on Aliexpress.com | Alibaba Group

Running down the raod the voltage should be in the 14.0 volt range.
A fully charged battery should read 12.6 to 12.8 after sitting with no load for 30 minutes or overnight.

If you are far off from these numbers number then you need to go fix the alternator if the 14 volt figure is not there or the battery if the 12.6 volts is not there after 30 minutes.

 

a $10 cheap multimeter from walmart is your friend.



Use it to test your grounds for resistance, then remove, clean, and re-install as necessary

I find ALL stock honda grounds are pitiful. usually cleaning the paint off and cleaning any bolt threads makes a large difference, let alone upgrading to thicker wire and additional ground locations.

I rarely see a honda with a bad alternator under 200k miles, as long as the car gets 50+ miles a week driving time

 

 

[/QUOTE]
True. I had "upgraded" my ground cable since the old one was giving me problems. Started to have the exact same problems mentioned here. The battery was new so it was very unlikely to be that. Replaced my ground again and it works just as new.
The voltage difference between the positive and negative pole was different from the Positive Pole and Ground