CRV Charging System

[JHZR2]

Figured I'd start a new thread, as I got help in the other, but it was aimed at an ABS issue.

2003 CRV, battery is a bit under 5 years old and shows 60% life. Battery light keeps coming on, after sitting a bit. But then goes out and seems fine, once you start driving?

Today I hooked up the meter and cranked, and while in the past, if I rev'd it up, eventually it'd start charging and be fine. But today... no go, sat at 11.6V headlights off, 11.4 headlights on. Thought the alternator was bad... then the cooling fans kicked on (HVAC left in defrost mode, engine nowhere near operating temp, so no idea why it was cycling, 45F or so ambient, after a frost). And now it's sitting at 14.6V, lights on or off.

Any idea why having the cooling fans cycle on enables the alternator to operate properly? I could buy a bad ground, somewhere, but the alternator continued to sit at 14.6V after the cooling fan turned off. There's something intermittent here, but I'm not sure where to look. I watched an Eric O vid on monitoring the field line from the alternator, but I don't have a wiring diagram (let alone Eric's expertise at debug).

Am watching a vid on how to replace the alternator, boy that looks fun... and ours has some minor damage in that area, condenser is shoved into the radiator, so a bunch of stuff is tweaked, so if the alt has to come out, it'll be a yet more fun job.

On my much newer and much different Accord Hybrid, the car won’t charge the 12v hotel battery in all cases, unless hvac or the lights are turned on.

My 1993 MB 300SD had an corroded exciter wire. I don’t think any voltage/current got to it. But the remnant magnetization in the alternator allowed it to self excite once there was some load on the battery, and the alternator was spinning at ~2k RPM. You may be seeing a similar situation

 

[brianl703]

My MB diesels all solely ground via battery to fender, then opposite fender to engine block.

The starter load passes through that? Typically the battery negative is connected to the starter, which provides another ground path to the engine.

 

[JHZR2]

The starter load passes through that? Typically the battery negative is connected to the starter, which provides another ground path to the engine.

Yes…

 

[brianl703]

Yes…

I have never before seen a battery connected that way, with just a single ground wire to the chassis. Not very redundant!

 

[vwmaniaman]

Son and I replaced the alternator on my daughters 07 CR-V this last Saturday. What a pain to change. We had to remove the power steering pump and reservoir to access the upper alternator bolt and the lower bolts on the alternator are hidden by the AC compressor. My Ancel 610 tester on live data would show it charging normally and then voltage would just start dropping. When it got down to 10.6 we shut it down and purchased an alternator. I owed her nothing since it was original and has over 250K on it

 

[JHZR2]

I have never before seen a battery connected that way, with just a single ground wire to the chassis. Not very redundant!

Don’t disagree. But this is a car with a 65A alternator, that can drive and operate with no working alternator or battery, after an EMP, and run nearly forever. So I guess it’s ok.

 

[supton]

On my much newer and much different Accord Hybrid, the car won’t charge the 12v hotel battery in all cases, unless hvac or the lights are turned on.

Yeah but does it flip the battery warning light on when it's not charging? Mine does, and my son said it all but conked out once on him.

on and I replaced the alternator on my daughters 07 CR-V this last Saturday. What a pain to change.

Yeah that's been holding me back, it's a mental block, not wanting to tear into it. I personally do not find this vehicle well designed, it's serviceable, but barely.

 

[JHZR2]

Yeah but does it flip the battery warning light on when it's not charging? Mine does, and my son said it all but conked out once on him.

No. Mine is actively controlled. My point was that yours too might have some sort of excitation control too. And that if something is wonky (technical term) could result in any number of issues.

Suffice it to say if the light is on, something is broken or wrong. The light in theory provides field excitation of the alternator, but it could be a dummy light that is computer controlled. You need to figure that all out.

 

[vwmaniaman]

Well it has been 5 days now since we replaced the alternator and no more battery charge light off and on. Stays off now.

 

[supton]

I found another video on how to change, this one does more work, but I think he removes a few things for better camera angles. He opts to remove the intake so as to get more access from the topside, rather than attack from the bottom. I've been dragging my feet on this, not sure why.

 

[Sequoiasoon]

I took out the intake on the '04 and the '08 to replace the starter. I did the AC compressor on the '04 that way also. Actually quite easy to make room to get to things.

 

[supton]

To wrap up this thread, I threw in the towel and dropped off at the shop. $550 and it's done. Didn't have much of choice, with my daughter wrecking one car, I found us at N-1 vehicles and needed this fixed ASAP.

Shop pointed something out that I flat out overlooked: when it was charging, it was charging at 14.6V, which is a bit hot. Regulator must have been acting up.