Little help with electrical issue

[m1949]

LITTLE HELP WITH ELECTRICAL ISSUE

My 06 has an electrical issue that has me stumped. Here are the symptoms:

1. Sometimes the battery is drained. This can happen if it sits 3 or 4 days, but also can happen immediately after I start it and drive for a few minutes. The battery issue is intermittent. The battery is fairly new. I've had it checked and it fully charges and can hold a charge.

2. Sometimes the warning chime has static when it goes off.

3. Rarely, at start up the instrument panel doesn't immediately register. Tach and warning lights and messages work but no gauges. After 10 or 15 seconds all the needles go to where they should be.

4. The alternator makes a loud whirring/whining sound. I recently replaced a bad wire which goes from alternator to battery connector/harness. The old one was almost broken in two. Whirring/whining sound continued.

I've recently replaced the 3rd brake light, which seems to be working right; and I also replaced the driver door control module. At first the driver window switch didn't work, but after resetting all the connectors it works right.

Any suggestions?

 

[afpj]

Have you had the alternator bench tested? Load test on the battery as well?

 

[Fless]

Have you had the alternator bench tested? Load test on the battery as well?

^^ This ^^ The whining/whirring bothers me... the alternator may have some AC ripple that causes charging to be ineffective.

Also, the battery cables on these tend to rot from the inside out, unable to carry the large currents they're designed to when new. Carefully inspect and clean the connections at both ends, and check the pos and neg cables and replace as necessary. You could load test them to see what the voltage drop is across the end points with a load (like the starter).

Is the body to engine ground strap intact from the firewall to the driver's side head? Condition?

 

[m1949]

Have you had the alternator bench tested? Load test on the battery as well?

Had battery tested and its good. I ordered a new alternator. This one has made a whirring/whining noise since it was installed. Seems to have gotten worse with time. I did find the ground wire from the firewall to hood was loose and a bit frayed. I replaced it this morning. Will see if new alternator and ground help.

 

[m1949]

^^ This ^^ The whining/whirring bothers me... the alternator may have some AC ripple that causes charging to be ineffective.

Also, the battery cables on these tend to rot from the inside out, unable to carry the large currents they're designed to when new. Carefully inspect and clean the connections at both ends, and check the pos and neg cables and replace as necessary. You could load test them to see what the voltage drop is across the end points with a load (like the starter).

Is the body to engine ground strap intact from the firewall to the driver's side head? Condition?

Thanks. I replaced battery cables about 30K miles ago. They look good. No corrosion I can see. I gave the battery a full charge this morning; it had gone down about 20% over night. just went out to check if it's holding charge since I replaced the ground cable from fire wall to hood. Battery was almost completely drained. So, its back to the drawing board. New alternator just arrived. I'm going to install it, but I can't see how a bad alternator can cause a battery to drain while the car is turned off and just sitting. This is very frustrating! I'm vision impaired and trying to run down what's causing this is a challenge. This is my wife's ride and our only transportation since I can't drive.

 

[Fless]

The cable from firewall to hood won't make a difference with the charging or draining. It's there to complete the electronic shield that the hood provides (like from secondary ignition static on the radio). The more important one is the braided bond from the rear of the driver's side head to the firewall.

I would recommend a parasitic draw test to see how much is being drawn while everything is asleep. Something like is shown here:

 

[m1949]

Yeah, I think a parasitic drain test and search is next. But that's something I'll have to pay to get done. I don't see well enough to test leads on individual fuses.

 

[rockola1971]

There are 4 possible causes to the symptoms the OP listed.

First is a bad battery. Has a weak cell and cant put out the correct voltage under load.
Second is a bad alternator. And if the alternator is the cause it certainly can ruin a battery due to overcharging.
Third is silver migration in the instrument cluster and this will showup as gray/white "dirt" on the back of the circuit board and usually can be cleaned off by isopropyl alcohol.
Fourth is bad ground(s) at the firewall, which can cause the BCM not to ever goto sleep which drains a battery down and can ruin it.

And its possible that any combination of the 4 can be happening at the same time stacking problems and making it hard to troubleshoot.

 

[m1949]

Thanks for the input. Here is where I'm at: 1. I recently had the battery tested and it was good. 2. Just took delivery on a new alternator which I'll install later today. 3. The cluster was rebuilt about 2 years ago. 4. The main ground from firewall to engine may be an issue. I'll check it.

I think the issue may have something to do with the door chime recently developing static when it chimes and sometimes cutting-off mid-chime. My car has aftermarket stereo and alarm systems. The OE radio had adjustments for door chime volume, so the radio and door chimes are somehow connected, maybe are on the the same curcuit? This makes me wonder if I have a parasitic short in one of these systems. Suggestions?