stereo install - power for clock & presets

[dotcentral]

The am/fm/CD died in my truck, so I'm trying to swap it out with a Sony am/fm cassette I had laying around.

Question. The power supply wire to let the presets and clock hold their memory. Should it have an inline fuse of some sort? Is the inline fuse important? I would think it is. The memory power wire seems to have some sort of blade connector. I figure it was part of the original fuse assembly. No idea how it works or what it plugs into.

I probably shouldn't run power through the memory wire without a fuse. Or am I being too cautious? How do I splice a fuse & fuse holder in? What size fuse?

Other than not having presets, if I don't hook this wire up until I figure out the fuse thing, would I be causing damage to something else?

[72hiboy4x4]

I believe the spade connector is supposed to go to a newer fuse box accessory port. I would tap an inline fuse to the wire and run it to a Constant 12v hot line at your current fuse box. use a .5 amp fuse (should be right-someone correct me if I am wrong)

the inline fuse you can get at any auto parts store. just connect it between the wire and the fuse box location you choose.

and no, it shouldn't hurt anything to not have it. but I personally find it irritating to not have the clock and tuner displays working right.

[dotcentral]

Thanks. Can I run constant power from the cigarette lighter instead? I am a little nervous about messing with the fuse box. I chipped it trying to change fuses last time I touched it.

[72hiboy4x4]

as long as your cig. lighter has CONSTANT power (even when starting the truck!) you can tap in there. but if your battery ever gets weak you will start to lose radio memory when you start the truck.
you could tap in at the starter solenoid, but thats a long ways to go!
probably the best thing to do is find a wire with constant fused power and tap in after the fuse box. the memory takes almost no juice, so the amp drew wont affect any other circuits.

[68F250]

Cigarette lighter is always hot, even while cranking.

[dotcentral]

I'll try the cig lighter. I have a year old 650 CCA (or there abouts) battery, I always seem to have plenty of juice.

I picked up a 5A and a 20 A inline fuse holder from radio shcak. $2.29 each. I'll put the 20 on the power and the 5 on the constant power.

Is it "5" or ".5". Or are they two different things? I want to use the old style glass fuses, not the blade type.

Thanks for the help so far.

[72hiboy4x4]

the .5 is a 1/2 amp fuse and the 5 is a 5 amp fuse. big difference ( in size inside also) i would think that you are overfusing the radio, but i doubt thats a problem. (almost all my '72's fuses are 20 amp for everything)

everything else sounds good to me.

enjoy the new tunes! looks like I gotta change out the one in my '74 (new to me) pretty soon.

[dotcentral]

Well, I should have said I have a 5 amp and a 20 amp fuse holder. I can probably put a smaller fuse in the 5 amp, if I have one.

Thanks for the advice guys. It makes feel a little better when I start messing with things I don't have alot of experience with.

[bluef250]

Check out the fuse block thread. Photo's ('70 model) and diagram (from '68 manuel) of stock fuse block are posted there. A schematic of the fuse block is on the thread for replacing the glass fuse with spade type. The hot fused circuit, accy fused circuits are shown. If you decide to run off the cigar circuit, for a temporary fix, remove the fuse, strip wire and put wire under output side of the fuse, and then push fuse in. Then you will see how it works. You can make permanent connections later.