The last person that owned my 240 hacked the stereo wiring harness to shits. I put all new wiring in so it doesn’t look like hell, till I found out that there is NO “switch” wire, the yellow one that powers down the stereo when the car is off. There IS two red constant wires, both stay on when the car is off. The only other wire left over is the ground. I know I’m not missing anything, there simply is no wire left over to be a switch.
So, the only thing I can think of is to throw a relay in there for when the car starts, and feed that wire to the radio. Has anyone done this before? Where should I hook it up to? I’d like to keep this from being a another hack job.
It’s a 1990. I supposed I posted before I really thought about it, but I should try to find a wiring diagram, see where the wire would have originally originated from within the car, but it looks like the interior was completley stripped at one point (theres a new carpet in there) and for what ever reason, the switch wire was never fed back in to the radio harness.
the blue wire on the radio harness is the ignition wire.
if that doesn’t work you can tap off the accessory wire at the wiring harness which is blue also.
the 12 volt constant is the red black stripe
the radio illumination is the red blue stripe
does that help a bit ?
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That explains the two red wires ( don’t think I’ve come across that before). I’ll give it a go this week. I didn’t really care about not having a radio, but now I’m trying to revamp some of the things that were never finished on the car. I thought the blue wire was a draw stright from the radio to power on an amp? I don’t think there’s a left over blue wire from the wiring harness, just those two reds and a black.
Newman, you don’t think the Radio fuse goes to one of the red wires? I’ll put the fuse on the voltmeter and see what happens when I turn the car on. Would be pretty cool if that works. I guess my concern is if I tapped in to something not designated for the extra draw and end up blowing fuse after fuse.
I’ll give it a go, never had to go in and play with the cars electronics before, but better time to learn now than never :headbang:
That explains the two red wires ( don’t think I’ve come across that before). I’ll give it a go this week. I didn’t really care about not having a radio, but now I’m trying to revamp some of the things that were never finished on the car. I thought the blue wire was a draw stright from the radio to power on an amp? I don’t think there’s a left over blue wire from the wiring harness, just those two reds and a black.
Newman, you don’t think the Radio fuse goes to one of the red wires? I’ll put the fuse on the voltmeter and see what happens when I turn the car on. Would be pretty cool if that works. I guess my concern is if I tapped in to something not designated for the extra draw and end up blowing fuse after fuse.
I’ll give it a go, never had to go in and play with the cars electronics before, but better time to learn now than never :headbang:
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that blue wire is also the same wire you use to power on an amp. you use the blue wire coming out of an after market head unit to power on the amp. or the radio ignition wire with an inline switch.
the other thing that came to mind is, why use a relay when one is not needed. For the relay to know you had turned the car on you would have to hook up a 12v switched wire, so y not just skip the relay and just run that 12v switch direct to the radios switched wire, problem solved.
the other thing that came to mind is, why use a relay when one is not needed. For the relay to know you had turned the car on you would have to hook up a 12v switched wire, so y not just skip the relay and just run that 12v switch direct to the radios switched wire, problem solved.
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Um… let me think.
To what I (think) I know about the set up, if I tap off an existing 12v switched power source in the car, I may draw more current than what that switch was intended for (say, the dash lights). My thought was by using a relay, I wouldn’t draw from thaw 12v power source, instead it would just tell the relay to turn on, and use it’s own source.
by all means, I probably don’t know what I’m talking about and confusing everyone. Here’s the scenarios I’m thinking of IF I can’t locate the original switch intended for the radio:
On the left side, I need to find out if tapping into an existing switched source will create a chain of one big draw.
On the right side, it will create an independent power source/
Sorry if I seem to be over thinking, BUT, I have a habit of not blowing stuff up, and understanding how something works before I f* something up
There is no need for a relay! Tap into the stock fuse box at any switch power fuse(try to use a fuse slot that is hardly used). A relay is overkill for a turn on lead to a radio. The radio requires so little power(for a turn on lead) you can just use and existing circuit. As for the main power the radio will require around 15 to 20 amps! Try to fuse this ,(main power)if you can!
Got it working. I know it’s petty stuff, but not having a radio in the car and leaving everything hacked is a little trashy. Tapped in to the fuse box and ran new wiring.First stime screwing with any of the car’s electronics :tup: Blasting Mudvayne at 15 Mph in the ghetto brings back memories.
