constant power line. I might be stupid.

[Lance-ftw]

Ok, I've installed a lot of stereos in modern vehicles but my new truck is older than I am so I'm 'learning' some things about how they did it back in the day.

I bought the truck a few weeks ago and unfortunately someone had cut the dash to fit a modern stereo and had said modern stereo already in there.

The stereo didn't hold any presets and the other day it made a pathetic little noise and began to leak electrical blood (smoke) upon inspection of the deck I found a burned up resistor and upon inspection of google I found out that brand of stereo was complete crap.

So, I jaunt off to BestBuy and pick up a new pioneer, I jaunt back to my house and feeling thoroughly jaunted I decide to go ahead and install my new stereo.

I trace out the cables from the original stereo and find my speakers (yay!) the antenna, and a red and yellow power cable. Now, from previous experience I know the red goes to the ACC power usually from the ignition so that you can turn the radio on without turning the car on but it still switches off when the car is 'off' and the yellow goes to a constant 12v supply. In cars it's usually tied into the cigarette lighter or dome lights prior to their switching device.

Now, here's where the problems start. First the yellow and red were spliced together to the ACC power, I check it out and it's only getting voltage while the car is in the on positition or running. I can't find a constant 12v and my fuse panel looks like Yahoo Serious' hair turned into wire.


So, I go hunting for my CIG behind the dash and figure I'll just splice off since I plan on redoing all the electrical in the truck anyway and it'll get me rolling. I pull the cable out, cut and splice in a new piece and check the voltage. It's 0. I turn the car into the ON position and it's 12v. Ok... am I missing something here, shouldn't it be reading 12v with the key out of the ignition?

I assume my cable splicing was bad (hard to assume that cause I'm a damn pro!) and I undo it and check the feed line... same story. 0v off, 12v on just like the ACC power. I check under the dash and start tracing wires only to find Yahoo Serious' estranged twin hiding back there and this time he's wearing an electrical tape bandana on his matted wire hairdo and I give up because of all of the little spiders.

So, I ended up splicing the yellow and red together to the ACC power and let it go for now, here's my questions.

In a 1970 Chevy CST/10 should I be seeing 12v on the lighter power supply with the truck off?

If yes, why the hell am I not?

If no, where WOULD I get a 12v constant besides the dome lights and do you know if it's a fused circuit or should I get an inline fuse for it?

I don't want to, under any circumstance, run this line directly to the battery. There have been too many chop jobs done on the electrical in this truck already I'm not going to add one more.

I have a number of other questions but they're more 'pure electrical' and I'll post them in the main forums. Thanks in advance for your time and sorry for the long winded post.

-Lance

[Bad70sbchevy]

I could be wrong, but the cigarette lighter should get 12v constant while off. I know on my radio, I got it running from the fuse panel using a one to two slot spade but it sounds like you can't in your case. What about running a wire straight from the battery (cant get more constant than that)? If your really worried about it, you can just run an inline fuse on it.

[Andy4639]

Truck fuse panel. Yes the cig should have 12 volts all the time. Do as I did. Buy a fuse panel at radio shack connect it to the 12 volt source in the main fuse block then run all the stuff you want off of it.

[stich626]

I've seen it switched, not factory, but if a guy has kids,, back then the bizbody police didn't take your kids if you popped into a store for a minute with kid(s) in the car/truck
and to keep the wondering kid from burning self it was switched,
also in cars that a person used the lighter for a dc to ac converter. so when the keys off the converter is off, and keep from killing the battery..
good luck MR YAHOO

[motornut]

once you find it
i put a little switch in to the right of the radio
up is on with no key/in mine lighter is always hot
middle off
down works with the key/normal