[Hazzea]

Hi,
I'm experiencing some strange electrical issues with my 1965 Mustang.

Everything worked fine until a Retro Sound radio was installed.

According to the workshop, the radio is hooked up with one cable going directly to the battery (constant power/memory) and one going to the ignition switch (trigger action).

First, when switching on the heater, the radio is shut off. When switching off the heater, the radio is turned on again. I have the kind of heater switch where the off position is to the left, and it's possible to select different fan speeds by flicking the switch to the right. This happens everytime I engage and disengage the heater.

Second, sometimes when starting the car, the instrument panel doesn't get any electricity. The gauges aren't working as well as the instrument lights. This can usually be resolved by slightly turning the ignition key counter-clockwise.

Third, when using the turn signals, sometimes suddenly the radio is shut off while the flasher freezes and the alternator lamp is lit. After a short moment the flasher continues to flash, the radio is turned on again and the alternator light goes out.

Could the ignition switch be responsible for these issues?

Best regards,
hazzea

 

[Driveway]

Sure sounds like the new radio is causing a sever power drain on you electric system. It is competing with the heater blower which is one of the highest draw items in the car. It uses two coils that heat up to control the speed of the motor. That is lots of power turned to wasted heat. Same type of issue with the turn signals. Does this radio have high draw speakers, power antenna, or an amp?

It is very possible the contacts in the ignition switch are corroded and also causing a resistance. When you move the key it is finding a better spot on the contacts.

If this is the original switch, I would go ahead and replace the switch portion anyway. It is not very expensive. The key section removes very easily so it will still match the doors.

Unlikely since it is a '65, but does this car have a generator?

 

[Hazzea]

Thank you for the reply!

The car has a new dual coil instrument panel speaker and two 4" Pioneer speakers + an amp and a subwoofer.

If this issue is caused by severe power drain, what could I do to prevent this? Would the battery type matter?

The ignition switch is original so maybe it's best to replace it.

The car is fitted with an alternator.

Best regards,
hazzea

 

[Driveway]

Unless the current battery an undersized piece of crap, it really shouldn't be a factor. There is only 1 wire with power going into the switch, and it can only support so much draw. And it sure sounds like a bunch you have added.

Look at putting in a switch activated relay to power the radio directly off the battery side of the starter relay. Just make sure all the wiring is large enough to support it.

 

[rex1965]

You could have the problem of the voltage dropping too much, which is what the other guys are saying in effect. The main power for the amp should be going directly to the battery, a fuse in bat side of it and a fuse in the neg side (the body ground may not be good enough) is recommended also. Then for your sense wires, since the electrical system in these vintage mustangs has such small wires, you may have to run the On sense to a relay like Driveway said. In addition make sure your battery cable connections and battery posts are clean, and coat them with either vasoline or one of the sprays to resist corrosion, when done, don't put it between the connection, only on the outside. Also your alternator may not put out enough current for your amp, you may need to use a voltmeter and check the voltage on your system with the amp on and with the amp off. If you do these things and still have trouble, you may need to install some capacitors in parallel to your sense wires. You may need the biggest battery you can fit into it also. My 2 cts. Good Luck.