Topic: Always one more fuse

[oldjeep]

Had the day off today, so I decided to swap in the free CD player that I got when we stripped my friends comanche.  Bought a plug at Best Buy and got all the wire hooked up.  Installed it completely without checking it - and it didn't work.

Pull it back out and hook up the old stock unit to make sure it still works - and it does.

So I start checking power, which I have on the acc wire but not on the always on wire.  Radio fuse in the footwell is fine.  Strange - can't figure out where the problem is so I break out the FSM.  Turns out that there is a little bitty fuse in the relay center that provides the constant + for the radio.  I guess the stock unit only uses that as a memory wire, which explains why the radio was always loosing my presets.

Now the dash speakers sound so good, I think I'll have to build a couple boxes into the cage for rear speakers.

[Jeffy]

Yeah, that 15A mini fuse controls power to the horn, lights and the radio.  I've blown many of those fuses.  Luckily they aren't $1 a pop like they were in the early days.

[oldjeep]

Yeah, that 15A mini fuse controls power to the horn, lights and the radio.  I've blown many of those fuses.  Luckily they aren't $1 a pop like they were in the early days.

There are 2 10 amp mini fuses on my 94.  One controls the radio, dome light and some other stuff I don't have - the other is for the horn.

[jfrabat]

I may need to check for this; my radio (and all other componentes) shut off when I turn the key from RUN to ACC...

[sharpxmen]

I may need to check for this; my radio (and all other componentes) shut off when I turn the key from RUN to ACC...

you probably used the 12v ignition rather than accessory wire - should be there from the stock radio. I got it already butchered so i went with a multimeter on the radio harness to figure it out (one by one)

you probably know but just in case - the accessory contact on the Jeep is on CCW from where you pull the key off, you need to press the little lever on by the key to be able to go there (this seems to be a north american thing, the european cars have it right before the ignition position).

[jfrabat]

you probably used the 12v ignition rather than accessory wire - should be there from the stock radio. I got it already butchered so i went with a multimeter on the radio harness to figure it out (one by one)

you probably know but just in case - the accessory contact on the Jeep is on CCW from where you pull the key off, you need to press the little lever on by the key to be able to go there (this seems to be a north american thing, the european cars have it right before the ignition position).

Well, I know the wiring is right, because it USED to work!  But now that you mention it, I was using the position before the RUN; I'll check tonight if turning the key CCW works (but I seem to remember it was actually the position before RUN that worked; could be wrong, though, as I have not used the Jeep as a daily driver for close to a year now...)

[Sine Deviance]

When I install a radio I ALWAYS run a new 12v constant with an in-line fuse from the + on the battery. Then I use the fuseblock's ACC/radio slot as my 12v switch point. When you install a modern headunit into an older car and you use the 12v constant in the factory harness you always run the risk of burning something up. You have to keep in mind that a new headunit pulls anywhere from 120-240 watts, whereas the factory radio probably pulled half that. The fuse won't always save you.

[Jeffy]

When I install a radio I ALWAYS run a new 12v constant with an in-line fuse from the + on the battery. Then I use the fuseblock's ACC/radio slot as my 12v switch point. When you install a modern headunit into an older car and you use the 12v constant in the factory harness you always run the risk of burning something up. You have to keep in mind that a new headunit pulls anywhere from 120-240 watts, whereas the factory radio probably pulled half that. The fuse won't always save you.

The main problem I've had is doing something stupid and shorting out the live wire when doing something else...     The shock from the horn is always fun too... 

[Sine Deviance]

The main problem I've had is doing something stupid and shorting out the live wire when doing something else...     The shock from the horn is always fun too... 

Heh, yeah, been there and done that. It's always a great idea to unhook your battery terminals before starting the project

[jfrabat]

Well, I know the wiring is right, because it USED to work!  But now that you mention it, I was using the position before the RUN; I'll check tonight if turning the key CCW works (but I seem to remember it was actually the position before RUN that worked; could be wrong, though, as I have not used the Jeep as a daily driver for close to a year now...)

Well, as could be expected, I was tulning the key the wrong way...  I guess I have gotten TOO used to druing the Toyota!

[oldjeep]

When I install a radio I ALWAYS run a new 12v constant with an in-line fuse from the + on the battery. Then I use the fuseblock's ACC/radio slot as my 12v switch point. When you install a modern headunit into an older car and you use the 12v constant in the factory harness you always run the risk of burning something up. You have to keep in mind that a new headunit pulls anywhere from 120-240 watts, whereas the factory radio probably pulled half that. The fuse won't always save you.

This is just a plain jane 10 year old basic cd player not some mega thumping head unit.  The 12v constant wire is running through the factory 10amp fuse in the relay center, the wiring isn't going to burn up

[Sine Deviance]

This is just a plain jane 10 year old basic cd player not some mega thumping head unit.  The 12v constant wire is running through the factory 10amp fuse in the relay center, the wiring isn't going to burn up

Well, notice I said 'modern'

Also, like I said, you can't always rely on fuses. They don't always pop like they're supposed to.

[oldjeep]

Well, notice I said 'modern'

Also, like I said, you can't always rely on fuses. They don't always pop like they're supposed to.

Can't count on fuses?  OK I'll just run 2/0 cable to everything just in case.

Now that is a kwality stereo install.  The dash is a bit beat on but the free CD player and speakers are installed.  Cost $50 for the wedge speaker pod, which is nice because you can actually hear the radio at 65MPH now.