Radio

[schooncj7]

OK I know this is not the most important thing in the world but I like my radio when I'm riding around in my CJ. Here is the problem I just got the jeep a few months back and just hooked up a radio and while riding the radio will go off for a couple of seconds and then come back on. I have a AMC 304 with a DUI distributor. The alternator is good and I have noticed that my voltmeter takes a dive when this happens. I have also done all the basics like check the wiring making sure not to have a ground somewhere. The only quick solution I can think of is to wire directly to battery! Help!!

 

[elwood blues]

If you're seeing the voltage on your volt meter dropping. You've got to be shorting a +12V wire to ground somewhere.

 

[elwood blues]

I'm not sure how wiring saavy you are. A stereo generally has two +12V inputs. One is a constant hot, in other words there is power there even when the key is off. This one draws a very low, but constant, amprage. This is the memory voltage, it keeps your clock running and your presets set. The other is the keyed +12V, this is the main power for the reciever and the amplifier for the speakers. You can always rewire the stereo, you only need three wires, the constant +12V, the keyed +12V and a ground.

DO NOT WIRE THE STEREO DIRECTLY TO THE BATTERY! Nothing good ever comes from wiring anything directly to the battery.

 

[kicknjeep]

I'm not sure how wiring savvy you are. A stereo generally has two +12V inputs. One is a constant hot, in other words there is power there even when the key is off. This one draws a very low, but constant, amperage. This is the memory voltage, it keeps your clock running and your presets set. The other is the keyed +12V, this is the main power for the receiver and the amplifier for the speakers. You can always rewire the stereo, you only need three wires, the constant +12V, the keyed +12V and a ground.

DO NOT WIRE THE STEREO DIRECTLY TO THE BATTERY! Nothing good ever comes from wiring anything directly to the battery.

EB pretty much sums it up other than make sure the for the keyed +12V has a fuse in line.

 

[schooncj7]

Yeah I have the wiring set up like you said. I will just have to look back over it again to make sure the wiring is not scraped and touching something causing it to ground. Thanks for the help

 

[Old Dog]

The radio could have a short internally, even if it is new.

 

[elwood blues]

You know what schoon7, the more I think about it, I'm wondering if you don't have a pinched wire somewhere. Or a chaffed wire somewhere else that it only touches metal when your driving. A wire that isn't part of the stereo wiring. A big wire that carries a lot of amps.

I wonder if the stereo is only shutting off because of the lack of voltage from a short somewhere else in your electrical system. Do you know what I mean?

Old Dog beat me to it, the stereo could be shorting internally. The problem is, unless you having a schematic for the stereo, it's going to be a PITA to find internally. Is there stereo new, used, did you get it from a junkyard?

 

[schooncj7]

That sounds like it may be the issue. Again it only happens while driving because I have listened to it for a long period of time while working on the jeep in my yard. I have also moved all of the wires while the radio was on trying to recreate the problem. Now I will start looking at other wires! Thanks

 

[elwood blues]

Okay, if it only happens when you're driving, it's got to be somewhere other than in the stereo wiring.

It could still possibly be internally to the stereo. But I'm betting you've got a short somewhere. If it's dropping the volt meter, and the stereo is shutting off. It's got to be a wire in a circuit that's carring a lot of amps. Check your spark plug wires too, if one of them are loose, or shorting itself to the bock, that would absolutely do it.

 

[CJ]

Yep - a short in the radio would not pull your voltage down (at least not noticeably), it would pop fuses though. You have a short in a pretty heavy gauge wire or most likely a bad main ground from the battery. Also check the main ground from the engine to the chassis / body.

 

[IOPort51]

you installed the radio and this was not a problem before the radio was installed?? how long after the install did the problem first show up??

 

[schooncj7]

There wasn't a working radio installed before I installed the new one so I didn't know this was a problem until I installed a new radio. The previous owner may not have worried about a new radio since the same thing may have been happening to him. I'll just give all the wires a good over look to see what I can find.

 

[kicknjeep]

And lets not forget the biggest wire stripper of them all, Check where any wire carrying a circuit enters at the firewall into the cabin because grommets do disappear leaving wire versus metal.

 

[schooncj7]

Ok I think I found the problem. The stem at the main lead on the back of the alternator is loose and just spins. I'm not sure how it broke but as i play with the wire you can watch the voltmeter dance. I will know for sure when I change out the alternator but that seems to be the problem. Thanks for all the help! My next question will be coming with the steering but i'm looking at a few things first