Questions and Answers
Strange Electrical Problem
Q. I own an 1988 VW Jetta which has recently developed a strange electrical problem.
I installed a new stereo system, complete with amplifier, CD changer, subs, etc... Since the installation, I have "blown" 4 receivers (the head unit) for some unknown reason. All connections and wiring to the unit and the system are correct to my knowledge and according to the advice given to me by the techs at Crutchfield where I bought the receiver.
The voltage with the engine off is a steady 12.3-12.6 volts. With the engine idling, voltage is a steady 13.9 volts. No fuses from any leads are blowing. I even fused the ground wire connected to the unit. The system will play for a few minutes before the receiver shuts down.
Could the constant high voltage when the engine is running be causing my problems? Is the voltage to high for my vehicle's spec's? Is my alternator faulty? Please help, 'cause I'm stumped.
Thank You,
BarryA. You do have a problem Barry. I don't know how much I can help you with this.
From what I see, all the voltages are right and there is no real reason for the units to blow. There is the possibility of a voltage spike from the alternator, but all the equipment that I'm familiar with have circuits in them to handle this. I'm really reaching here, but do you have the right fuse in the circuit? Most stereo equipment use a 10 amp fuse for protection. If you have a higher amperage fuse that you are not protecting the equipment properly.
One thing you might want to try is measure the voltage going into the equipment. You can try installing a resistor to lower the voltage to about 12 or 12.5 at that point and see if that helps. Outside of that, I just don't know what else to suggest to you.
I'm sorry I can't be of more help than that.
