Thanks. So in a car there is nothing in-line in a normal car setup that cuts amps volts or anything down so I won't blow them up. Good.
Testing car radios - what's needed?
- Thread starter tallhair
- Start date
Thanks. So in a car there is nothing in-line in a normal car setup that cuts amps volts or anything down so I won't blow them up. Good.
commando1
Old Man with a Hat
The guages in your old Mopars are 5V. On the instrument circuit board, there is a voltage regulator that converts the car's 12V to 5V.
radio too?
commando1
Old Man with a Hat
No. Just gauges. Everything else in the car is 12Vdc.
Exactly.
The only exception would be if you are checking a 50's or earlier radio. If you have one, get back to me and I can help you set that up.
Thanks again John. I don't have any 50's radio's but someone reading this thread might so I'm glad you clarified for future readers.
Those cars were 6V with generators right? Probably a whole other thread LOL
6 volts and positive ground.
tallhair, all you seem to be after with this is a quick test. Pop the 12v battery out of your DD and use it... hook period correct speakers to it before power... JIC. The ohms of the speakers would make a difference and if you used some of the newer low impedance ones you might hurt something. Quick function test, no dangerous electricity so you can touch anything... then post for our enjoyment and possible sale.
Wollfen
Old Man with a Hat
I remember someone mentioning that when these old car radios are dead it is usually something simple and also usually an easily replaceable diode or internal fuse? Anybody remember who it was? Would be good information for checking our radios even if they seem Kaput.
commando1
Old Man with a Hat
Kids today don't know how to trace a circuit board.
furyus 67
Senior Member
As long as you have a basic understanding of the components your working with its not difficult. If at all possible find a "factory" example of the power supply plug to the radio in question. The simplest radios I've worked with are a single constant power supply, something with a direct feed to a 12v supply. The "other" power wire is nothing more than a switch. Basically a power wire for the power wire. Most of the time this wire is powered through the ignition "accessory" position which is also energized in the "run" position of the ignition. This allows digital radios to maintain a "memory " of time and audio settings through the "constant " power wire with out a full power draw on the battery essentially draining the battery. Next will be the ground wire, directly connected to the negative on the "bench" battery . Sorry I couldn't get the pics up today, work lasted a bit longer than I thought it would. I will get them up tomorrow if you can still use them.
Oh, ok. The item pictured above is a transformer or aka a "power supply".
It converts 110v A.C. household current to a lower votage and current by means of smoke, mirrors, voodoo, and pixie dust...
Don't tell him that ****, you know very well that there aren't any mirrors in a power supply ! But if you let the smoke out of one it won't work anymore.
saylor
Senior Member
my old man restored jags, i wish he was here id show him that lucas picture that is effing funny.
driving around in a 100k car and have to tap the oil gauge on the dash with your finger to unstick the needle heh.
HEY - on that ^^ power wire for the power wire ^^ - that acc. wire.. in my experience that is 5v not 12v, so be careful dorking around.
try not to die -
- saylor
driving around in a 100k car and have to tap the oil gauge on the dash with your finger to unstick the needle heh.
HEY - on that ^^ power wire for the power wire ^^ - that acc. wire.. in my experience that is 5v not 12v, so be careful dorking around.
try not to die -
- saylor
Jaguar was going to start producing their own line of car radios, but the engineering department could never figure out how to make them leak oil.
furyus 67
Senior Member
I've never measured the voltage at the acc. wire on an older car(pre-80's) My experience with it, I was pulling 12v from it. I would hook it and the constant up to a switch (if I didn't use the ignition) .
Accessory feed is 12 volts. They reduce the voltage to 5 volts for the gauges.
furyus 67
Senior Member
I'm out of work a little earlier today, do you still want some pics tallhair??
Yes please
Anyone have an older speaker for the low ohm radios they could sell reasonably? I'll use it to test these radios.
Send me a convo please and we'll work out details.
Send me a convo please and we'll work out details.
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