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Radio looses presents after cranking

1K views 8 replies 6 participants last post by  jseabolt 
#1 ·
I've had this happen on 2 cars. My 1968 Ford Fairlane and now my 1987 Citroen 2CV.

With the Fairlane I got so tired of this I removed my Sanyo tape deck and installed one of those "old school" analog radios which sounds awful. I was taking the memory signal off the cigarette lighter.

So the other day I almost finished up my radio installation on my Citroen and now it is doing the exact same thing! I tapped into the "always hot" wire coming off the ignition switch since this car was not wired for a radio from the factory.

The radio I am using is a Pyle which I realize is not top notch but sounds better than car radios of the past.

I have not got the speakers permanently mounted yet. Long story.





My guess is when I crank the engine over, the starter motor pulls so much power it causes a massive voltage drop so power going to the radio falls below the voltage threshold of keeping the radio memory presets.

I have not had this happen with my other cars. I would guess the battery maybe a bit weak? But even with those cars, when the battery was too weak to crank the starter over, I never lost any presents.

Any idea of how to solve this issue? Besides installing a battery for a diesel pickup truck with twice the cold cranking amps?

My idea was to find a small rechargeable 12 volt battery and place it between the ignition switch and radio along with a diode. That way the battery stays charged but doesn't try to back feed the electrical system and drain it.

Trouble is I have yet to find what I am looking for. I'd like to find one slim enough and secure it underneath the battery with Velcro.

I've seen those devices that you plug into a 9 volt battery into which plugs into the cigarette lighter that is supposed to hold the presents if you disconnect the main battery.

Any idea if using a 9 volt battery instead of the car's battery to power the presets would last any length of time?

Anybody ever had this problem and found a solution?
 
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#2 ·
print and perform this test...

http://i.imgur.com/Mo57rdb.jpg

then do tests 2 and 5 while cranking..

test 5 will go to a power distribution terminal.. on a ford it might be the threads of the stud sticking out the starter relay.

you could always run a separate fused power cable to the underdash area.. so you are getting direct battery power.

if your battery cables are too thin. you will have too much voltage drop while cranking. if the terminals are dirty or loose at the starter relay.. you could loose enough voltage while cranking.

perform the test.. not just on the cars effected.. but on several cars that work normally.. so you know what the readings should be..
 
#3 ·
My guess is when I crank the engine over, the starter motor pulls so much power it causes a massive voltage drop so power going to the radio falls below the voltage threshold of keeping the radio memory presets.
If it was pulling the battery low as stated above, the motor would not start.

I suspect you have the radio memory connected to a source that switches off during starter cranking. Try temporarily installing a jumper wire directly from the battery's positive post to the radio memory wire and see if this solves the problem. If this solves the problem, you can look for a fused power source that maintains voltage during cranking, or install a new fused memory wire from the battery to the radio memory.
 
#5 ·
There should be two power wires for the radio, If I remember right, red and yellow....... one is for the presets and should be hooked to an always hot source (hot with key "off") the other to a switched source. If the vehicle sits for long periods of time (months), you should disconnect the battery. (you'll lose the presets but have a charged battery)
 
#6 ·
I've had this happen on 2 cars. My 1968 Ford Fairlane and now my 1987 Citroen 2CV.

With the Fairlane I got so tired of this I removed my Sanyo tape deck and installed one of those "old school" analog radios which sounds awful. I was taking the memory signal off the cigarette lighter.

So the other day I almost finished up my radio installation on my Citroen and now it is doing the exact same thing! I tapped into the "always hot" wire coming off the ignition switch since this car was not wired for a radio from the factory.

The radio I am using is a Pyle which I realize is not top notch but sounds better than car radios of the past.


I have not got the speakers permanently mounted yet. Long story.





My guess is when I crank the engine over, the starter motor pulls so much power it causes a massive voltage drop so power going to the radio falls below the voltage threshold of keeping the radio memory presets.

I have not had this happen with my other cars. I would guess the battery maybe a bit weak? But even with those cars, when the battery was too weak to crank the starter over, I never lost any presents.

Any idea of how to solve this issue? Besides installing a battery for a diesel pickup truck with twice the cold cranking amps?

My idea was to find a small rechargeable 12 volt battery and place it between the ignition switch and radio along with a diode. That way the battery stays charged but doesn't try to back feed the electrical system and drain it.

Trouble is I have yet to find what I am looking for. I'd like to find one slim enough and secure it underneath the battery with Velcro.

I've seen those devices that you plug into a 9 volt battery into which plugs into the cigarette lighter that is supposed to hold the presents if you disconnect the main battery.

Any idea if using a 9 volt battery instead of the car's battery to power the presets would last any length of time?

Anybody ever had this problem and found a solution?

You need to go back and look at the wiring instructions, the memory wires one yellow the other black, if my memory serves me, need to be wired independent of the red power wire. The memory connects to full time power that is only disrupted if the battery is disconnected. This is a low power circuit that is always on.


The red wire runs the heavy users like the amp it is on the cars B+ switched circuit for house keeping operating power when running, but not on starting circuit.


Bogie
 
#7 ·
That's how I have it hooked up. I have the yellow wire running to the terminal on the ignition switch that is hot all the time. The red wire get's power only when the ignition switch is in the run/accessory mode and the black wire to the chassis.

UPDATE:

I've not had a chance to follow the instructions that were posted but
the last four or five times I've cranked the engine over I have not lost my memory settings. So what is going on?

I've got one of those digital voltmeters that plugs into the cigarette lighter. I wired in a power point to the "hot all the time" wire to recharge my cell phone I'm getting some weird readings.

When I first plugged it in, it says exactly 12 volts yet the engine does not struggle to turn over. Usually a battery that reads below 12.6 volts is weak and will not turn an engine over. However this is a 600 cc engine. So ordinarily it might not have enough balls to turn a 2 liter engine over.

Once the engine is running, the voltage varies as high as 15 volts at times. At idle the voltage may drop as low as 12.3 volts. Then barely rev the engine and it jumps to 14.3 volts. This car has an alternator and an external voltage regulator. I would expect this from a dynamo/generator but not from an alternator. Unless the idle speed needs to be bumped up a bit and it's below the charging threshold. I checked the idle speed and it was at 700 rpms which is supposed to be correct.

I would expect some variation but only .5 volts. I think I checked this voltmeter on my Subaru and it did not vary as much.

Last time I seen a battery read 15 volts was on my dad's Ford Tractor. I was just wondering if it was charging so I checked it one day with my voltmeter. Turns out the battery was low on water. After I topped it off, the readings fell to around 14.3 volts.

The battery on this Citroen is one of those "maintenance free" batteries that you cannot top off with water. Yeah right. We once had an 85 Chevy Cavalier that had one of those from the factory and it died suddenly one day for no apparent reason.

My guess is the battery is just weak.

With my 68 Ford, the battery on that car may not have enough cold cranking amps so the same thing could be happening.
 
#8 ·
It could be intrupted because you are using the hot at all times at the key itself.

Grab 12 feet of wire and just drape it over the fender than through the passenger or drivers door whatever side the battery is on. Keep that wire out of the engine bay.

Wire the memory directly to the battery. If it still does it it is a good chance it is your deck. If not then find another hot at all times spot and use that.

Here is a $20 radio that I love. It has Bluetooth, usb port, 3.5 input, as well as rca jacks, a remote and other junk.

It does not have a CD player or dancing light show that radios with similar features costing 10 times as much have.

https://www.walmart.com/ip/Mechless-AM-FM-Tuner-with-Bluetooth/54596679#about
 
#9 ·
Another thing to consider. It might be the amount of cranking I'm doing. This car has a manual choke so sometimes I have to "adjust" the choke based on the ambient temperature and if it fires up within a couple of seconds, it seems to be OK.

I know these are not top notch radios but those Pyle and Dual radios for around $30 are pretty good. I have a Dual in my Fiat Spider and a Pyle in my Citroen and I'm getting ready to install a Pyle in my Trabant.

One thing I like about these radios that lack a CD player is they are not as deep so they fit better in older cars with limited space between the dash and firewall.

SD cards is where it's at! Burning CDs is so 2000s....

One problem I had with my Fiat Spider was, there was this spaghetti of wiring behind the radio console, every time I'd insert the radio into the console, it would unplug either the courtesy light, cigarette lighter and/or emergency flasher button out of their sockets!



One way I solved that was to get rid of all the wiring for the power windows. The car was wired up for power windows from the factory and if I wanted power windows all I'd have to do is install two switches and two motors.

The relay panel even has relays for them as well as fuses in the fusebox!
 
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