ron88 Posted July 2, 2008 Report Share Posted July 2, 2008 I've begun to have problems with my radio, an Alpine CD unit (not very old, and not often used). It cuts out completely when the engine is idling. And, it also cuts out when the I switch the lights on. It works well in the accessories position, but not when the ignition is on. My garage says the radio is fault. I was going to accept this, except I have now noticed that, at an idle, the amps are not charging as usual. In fact, they are discharging, and occasionally quite a bit (WAY over with the lights on). There is also a faint glow from the red generator light (I have an alternator installed). Also - when the radio cuts out, the turn signal indications are slow to function, or fail completely. Is the radio causing all this, or is something else at fault? I'm thinking of disconnecting the power from the radio (or, just leaving it off) and driving around to see if the other things still happen. I do notice the electrical drain (at idle) even with the radio off. Thoughts welcome. Could it be an alternator fault? or an ignition fault? Quote Link to post Share on other sites
piman Posted July 2, 2008 Report Share Posted July 2, 2008 Hello Ron, I don't know anything about radios, (new fangled modern things!) but it sounds to me you need to check the fan belt tension as a start or else verify the state of the alternator. Alec Quote Link to post Share on other sites
4Mal Posted July 2, 2008 Report Share Posted July 2, 2008 I guess whilst you are checking the other things, check out the battery and connections... Quote Link to post Share on other sites
ron88 Posted July 3, 2008 Author Report Share Posted July 3, 2008 I guess whilst you are checking the other things, check out the battery and connections... Battery and connections fine; plenty of juice. Plus, good tension on the fan belt. Why do I think there is some "electrical box" that is causing this? Quote Link to post Share on other sites
Rhodri Posted July 3, 2008 Report Share Posted July 3, 2008 Is the power to the radio via an inline fuse, perhaps this is not making proper contact, so when the electrical demand is high elsewhere the radio loses out due to high resistance? Quote Link to post Share on other sites
ron88 Posted July 3, 2008 Author Report Share Posted July 3, 2008 Is the power to the radio via an inline fuse, perhaps this is not making proper contact, so when the electrical demand is high elsewhere the radio loses out due to high resistance? That's possible, and I will check it. There is also a school of thought that says some of the internals of the alternator are going out. I think it's back to the garage time. A new alternator is cheaper than a new radio! Quote Link to post Share on other sites
piman Posted July 3, 2008 Report Share Posted July 3, 2008 Hello Ron, reading later responses, I have to assume that the radio is fed via a fuse? The other thing that can cause the symptoms you mention is an earth fault causing a partial short. However if the radio is correctly fused it should just blow the fuse. A high resistance or poor contact in the radio's fuse holder will not cause your problem, given the symptoms you describe. I still believe that you have an alternator fault. If you have a battery charger, fully charge it (24 hours) and then see how your car behaves. If all is well for a short time then it is certain to be that the battery is not getting charged. Alec Quote Link to post Share on other sites
angelfj Posted July 3, 2008 Report Share Posted July 3, 2008 Hello Ron, reading later responses, I have to assume that the radio is fed via a fuse? The other thing that can cause the symptoms you mention is an earth fault causing a partial short. However if the radio is correctly fused it should just blow the fuse. A high resistance or poor contact in the radio's fuse holder will not cause your problem, given the symptoms you describe. I still believe that you have an alternator fault. If you have a battery charger, fully charge it (24 hours) and then see how your car behaves. If all is well for a short time then it is certain to be that the battery is not getting charged. Alec Alec: do you have a dc voltmeter? If you do, measure the voltage at the battery and compare it to the voltage at the radio/CD. First with and then without the engine running. There should be less than 0.50 volts difference between the battery and radio. Also, if you have the original owners manual, determine the minimum voltage for which the radio will operate. If you have a series of poor (high resistance) connections, there will be a significant voltage drop and perhaps insufficient voltage at the radio. If your alternator is OK, the voltage should rise equally when the engine is running and the voltage at the battery and radio will be higher, but possibly not high enough. Give us a report. Quote Link to post Share on other sites
Dazzer Posted July 4, 2008 Report Share Posted July 4, 2008 I've begun to have problems with my radio, an Alpine CD unit (not very old, and not often used). It cuts out completely when the engine is idling. And, it also cuts out when the I switch the lights on. It works well in the accessories position, but not when the ignition is on. My garage says the radio is fault. I was going to accept this, except I have now noticed that, at an idle, the amps are not charging as usual. In fact, they are discharging, and occasionally quite a bit (WAY over with the lights on). There is also a faint glow from the red generator light (I have an alternator installed). Also - when the radio cuts out, the turn signal indications are slow to function, or fail completely. Is the radio causing all this, or is something else at fault? I'm thinking of disconnecting the power from the radio (or, just leaving it off) and driving around to see if the other things still happen. I do notice the electrical drain (at idle) even with the radio off. Thoughts welcome. Could it be an alternator fault? or an ignition fault? Hi Ron Reading the thread, the first thing I would check is the live feeds to the CD unit, on modern CDs there are usually two, and it sounds as though one of them is shorting on something. I would disconnect the CD altogether and see if the charging problem disappears. If it does, refer to the alpine cd installation manual(download off the internet if you don't have the original) and start from scratch to reconnect. I had the same problem with a Sony CD, but once installed correctly works fine. Cheers Dazzer Quote Link to post Share on other sites
ron88 Posted July 7, 2008 Author Report Share Posted July 7, 2008 I'm pretty sure I have an alternator fault. At idle, AND at speed, the amps show a discharge and there is also the pale red glow of the generator light, never brighter, or off completely, but a glow all the time. The indicator lights likewise are slow to respond, and the discharge increases greatly once headlights are added. There is no positive charge to the battery at any stage. As I have an MOT due, I am going to bring this in within the next two weeks and get the alternator checked and replaced, if necessary. Then I'll focus again on the radio. Possibly a linked problem, but maybe not. I am also now noticing a "revving" of the engine +/- 400 rpm at idle plus backfiring. So off to the garage, and I'll report back. Quote Link to post Share on other sites
ron88 Posted July 18, 2008 Author Report Share Posted July 18, 2008 I'm pretty sure I have an alternator fault. At idle, AND at speed, the amps show a discharge and there is also the pale red glow of the generator light, never brighter, or off completely, but a glow all the time. The indicator lights likewise are slow to respond, and the discharge increases greatly once headlights are added. There is no positive charge to the battery at any stage. As I have an MOT due, I am going to bring this in within the next two weeks and get the alternator checked and replaced, if necessary. Then I'll focus again on the radio. Possibly a linked problem, but maybe not. I am also now noticing a "revving" of the engine +/- 400 rpm at idle plus backfiring. So off to the garage, and I'll report back. Yep - needed a new alternator and seems everything sorted. Odd that it started with the radio, but everything went south fairly quickly from there... Quote Link to post Share on other sites
robgeev Posted July 18, 2008 Report Share Posted July 18, 2008 It was probably the only thing that cared about its line voltage! Ignition perhaps may have suffered a bit, but not enough to die altogether. Good luck. Rob. Quote Link to post Share on other sites
'66 tr4a Posted August 2, 2008 Report Share Posted August 2, 2008 I have virtually the same problem with my new Becker Mexico- on the highway or on country roads it works fine but in the city it cuts out after just a 5 to 10 minutes- the radio has been checked and performance tested by the dealer and showed no problems. Since the radio is directley connected to the battery and the battery is charged regularly I fear the generator is simply to weak for the radio. Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.