radio in a 70
11-09-2007, 03:10 PM
#1
3rd Gear Member
Thread Starter
Join Date: Aug 2007
Location:
Posts: 755
radio in a 70
works fine but when i turn the car off after i set all my settings it loses all the memory. and i have all the right wires connected i believe. my buddy says it does it also in his 70 fastback. any idears?
11-09-2007, 03:16 PM
#2
4th Gear Member
Join Date: Aug 2007
Location: Houston, Texas
Posts: 1,692
RE: radio in a 70
Should be a red and yellow power wire. Red goes to switched, yellow goes to battery +. At least on most of the radio's I've seen. Some could use different wires.
If your wiring is correct, you must have a bad radio.
If your wiring is correct, you must have a bad radio.
11-09-2007, 07:33 PM
#4
1st Gear Member
Join Date: Dec 2006
Location: Sacramento, CA
Posts: 144
RE: radio in a 70
You must have the battery (constant) and the battery (switched) hooked up properly in order to keep your stations. If you don't have the battery (constant) hooked up to a source that runs constant + voltage, then you will lose all memory (including preset stations). My guess is your buddy got it wrong on his and then helped you install yours. 
haha. Just giving you a hard time. It could be a bad radio, but unlikely that both of you have a bad radio with the same issue. It's an easy enough fix. As for the coloring of the wires, just depends on the manufacturer of the radio. On most radios, there is a sticker that shows what color of wires go to what. Just make sure the one marked B+ (constant) is hooked up to a wire that's always positive, and the B+ (switched) is hooked up to a wire that reads positive only when the car is turned to ACC or ON (such as the post on the back of the ignition switch). If there is no wiring sticker on the radio, give me the brand and model of the radio and I can probably find out for you.
haha. Just giving you a hard time. It could be a bad radio, but unlikely that both of you have a bad radio with the same issue. It's an easy enough fix. As for the coloring of the wires, just depends on the manufacturer of the radio. On most radios, there is a sticker that shows what color of wires go to what. Just make sure the one marked B+ (constant) is hooked up to a wire that's always positive, and the B+ (switched) is hooked up to a wire that reads positive only when the car is turned to ACC or ON (such as the post on the back of the ignition switch). If there is no wiring sticker on the radio, give me the brand and model of the radio and I can probably find out for you.
11-10-2007, 07:24 PM
#9
1st Gear Member
Join Date: Dec 2006
Location: Sacramento, CA
Posts: 144
RE: radio in a 70
Did you check the radio for one of those stickers. I've seen very few radios that didn't have a sticker displaying what color of wire was for what. If no sticker, then you could go with best guess, let me elaborate...
Typically, your ground is going to be black. Your power wires (switched and constant) are usually red and yellow. Your remote is usually blue. There might be some sort of variation. Additionally, the power constant, power switched, ground, and remote are all usally right next to each other on the plug that plugs into your radio. The blue remote wire, if it has one, shouldn't even be hooked up. That wire is for accesories like amps, cd changers, etc. Just tuck it away making sure it's not exposed. Don't mess with the black wire, it should already be grounded or your radio wouldn't be working at all. Now that I mention it, that could also be giving you trouble. Make sure you have a clean connection withthe ground.
As for the other two wires, the ones that should be some variant of a red wire and a yellow wire, try switching them around. Use a test light to make sure you've got one of the wires connected to a constant power source, and make sure the other wire is connected to something with a switched power source. Like somebody else mentioned, the yellow is usually your "constant", and the red is usually the "switched". To use the test light, clip the aligator clip to your dash somwhere (this is your ground), touch the pointed tip w/bulb on the other end to the wire you're testing. When the bulb lights up, you've just completed the circuit and have found yourself a positive wire. Try it out on some of your fuses in your fuse box. A "constant" powered source will light the bulb regardless of key position, a "switched" source will only light the bulb when the key is turned to "on" or "acc".
Some pointers...
1. When testing wires, do everything in your power not to poke through the protective coating on the wire. Try to find the terminated end and touch the test light to that.
2. Don't strip off a long length of coating on one end of the wire, wrap it around a fuse, then push it back into the fuse panel! For a cleaner job without having to solder, go to Wal-mart or local auto store and pick up a solderless crimp set for10 bucks. Usually comes with everything you'll need and it's easy to use.
3. Don't leave any bare wire exposed. May result in a short later down the road.
I don't mean to insult your intelligence, it just doesn't sound like you have any experience with wiring as this should really be an easy fix assuming it's just an installation issue. That's why I'm trying to break it down "barney" style for you with how to use a test light and everything else. Good luck and let us know if you still have trouble.
Typically, your ground is going to be black. Your power wires (switched and constant) are usually red and yellow. Your remote is usually blue. There might be some sort of variation. Additionally, the power constant, power switched, ground, and remote are all usally right next to each other on the plug that plugs into your radio. The blue remote wire, if it has one, shouldn't even be hooked up. That wire is for accesories like amps, cd changers, etc. Just tuck it away making sure it's not exposed. Don't mess with the black wire, it should already be grounded or your radio wouldn't be working at all. Now that I mention it, that could also be giving you trouble. Make sure you have a clean connection withthe ground.
As for the other two wires, the ones that should be some variant of a red wire and a yellow wire, try switching them around. Use a test light to make sure you've got one of the wires connected to a constant power source, and make sure the other wire is connected to something with a switched power source. Like somebody else mentioned, the yellow is usually your "constant", and the red is usually the "switched". To use the test light, clip the aligator clip to your dash somwhere (this is your ground), touch the pointed tip w/bulb on the other end to the wire you're testing. When the bulb lights up, you've just completed the circuit and have found yourself a positive wire. Try it out on some of your fuses in your fuse box. A "constant" powered source will light the bulb regardless of key position, a "switched" source will only light the bulb when the key is turned to "on" or "acc".
Some pointers...
1. When testing wires, do everything in your power not to poke through the protective coating on the wire. Try to find the terminated end and touch the test light to that.
2. Don't strip off a long length of coating on one end of the wire, wrap it around a fuse, then push it back into the fuse panel! For a cleaner job without having to solder, go to Wal-mart or local auto store and pick up a solderless crimp set for10 bucks. Usually comes with everything you'll need and it's easy to use.
3. Don't leave any bare wire exposed. May result in a short later down the road.
I don't mean to insult your intelligence, it just doesn't sound like you have any experience with wiring as this should really be an easy fix assuming it's just an installation issue. That's why I'm trying to break it down "barney" style for you with how to use a test light and everything else. Good luck and let us know if you still have trouble.
11-10-2007, 07:33 PM
#10
3rd Gear Member
Join Date: Dec 2006
Location:
Posts: 815
RE: radio in a 70
I agree with the masses. Yellow wire on a15 or 20 amp fuse straight to the + post on your bat. The blue is usually a remote for a amp or power antenna. Only powers up when the radio power is on.
