I seem to have an electrical problem that I have been investigating with no luck and was hoping someone might be able to help out. There are three noticeable problems that seem to be linked together but I have not been able to find the solution.

1. Voltage gauge seems to read .3 volts lower then actual battery voltage.

2. Door locks will only work during a blue moon. They click but there is not enough juice to actually lock or unlock the door. On rare occasion they work perfect.

3. The radio will pop and snap when the blinker is turned on or the brake is applied. Spark noise can be heard thru the radio even if a CD is in and the volume is turned all the way down. I would expect this if listening to A.M. but since it happens when using the CD player I suspect it has something to do with the power supply.

My first solution would be a bad ground. I have checked and cleaned all the ground locations I can find.

1. Lower left transmission bolt
2. Back left side of engine.

I then moved on to the power by checking and cleaning the power distribution stud by the battery.

Nothing has seemed to improve the problem, if anyone knows of a ground location I have missed or has other possible solutions I would gladly appreciate the advice.

Thanks

:confused

 

The cluster voltmeter measures the voltage after the ignition switch and almost all of the cars electrical load goes through the ign sw contacts and the voltage drop across the switch is about 0.3 volts, so your voltmeter is normal.

The door locks may not be getting the full 12 volts due to a poor ground on the lock coil. Measure the voltage across the coil wires and determine if they are getting 12v. If so, then look for mechanical resistance to the solenoid armature.

The radio has a capacitor on the 12v line to eliminate voltage pulses (from applying the brake, turn signals etc., your radio may need this capacitor replaced. Also, each speaker has its own amplifier and they also have a bypass capacitor to eliminate voltage pulses from getting into the speakers and they have a finite life and may need replacing. The speaker amplifier capacitors are the more likely cause of your pops. Ignition pulses getting into the radio on the am band are usually caused by an open ground on the shield of the coaxial cable that goes to the antenna. Since you hear ignition pulses even on CD, I would replace the bypass capacitors on the speaker amplifiers. From an earlier post, I believe that Bose will rebuild your speaker amplifiers under their lifetime warranty. I would at least call them and ask about this. I doubt your radio problems are a result of a ground problem, with the exception of the antenna cable.

 

Thanks for the advice jfb:

I will do some closer evaluation of the speaker amplifiers and change the capacitors if needed. One reason I was going after a bad ground was I measured .25 volts between the ground wire for the radio and the negative side of the battery. This voltage grew to .83 when the brake was applied. Does this observation seem unusual to you? I would think there should be no measurable voltage between a ground wire and the battery unless something was increasing the resistance on the ground wire.

Thanks again

 

There shouldn't be any ground current from the stoplights through the ground wire on the radio! The stoplights are grounded on a frame member at the rear of the car. One other suggestion I have for your speaker whine problem because this happens to me occasionally, is to clean your battery cable connections to the battery. My radio is out of the car and yesterday I heard alternator whine which I cured by loosening and tightening each battery terminal bolt. I have a known corroded positive cable lug. I haven't listened close up to my speakers, so I don't know where the whine comes from, but I can see how one might think that it is coming from the speakers. Another symptom of poor battery connection is your ac/heater control playing tag on the lights and readout. This was my clue yesterday to go clean the battery contacts again.

 

I have cleaned the battery connections but replacing the ground wire on the battery has been on my to do list for a while now, who ever had the car before me cut the end off and put on a bolt on connector. I will probably tackle that this weekend and see if it makes any difference. Do you know where the ground point is at in the rear of the car, I thought it wouldn't hurt to check it. Thanks for your input on this problem it has been helpful.

 

I have tried those bolt on replacement battery lugs. They don't work worth a crap! They are extremely unreliable. Get a brand new battery ground strap and I am sure your problems will be over.