Strange noises coming from around automotive battery

[JulieB888]

Hey Folks,
I am having an issue that I am kind of worried about. It would be great to have some input from those knowledgeable about these things.

I have a 1992 Roadtrek, on a dodge ram van. Yesterday after i strated it, I noticed that there was a subtle ring, followed by a click while it was idiling. They both occured in the same order, following thw same intervals. When it began to move these noises continued for a minute and then they went away. I drove for about half hour and then parked. When I started the van later that night I noticed that they were back. I opened the hood and listened. They seemed to be coming from around the automotive battery. Everything under the hood looked and smelled fine. When I got back in the cab, I noticed that the clicking sound was synced with the systematic dimming of the lights inside the coach. This systematic dimiming always happens when the engine is running. The headlights and the dash lights were normal. I turned on the engine 3 more times last night and this whole process would it repeat itself. However when I started the van this morning the noises were gone. I am a bit worried. Should I be?

A few days ago my alternator belt was making a whining noise, when it was very cold and rainy. The noise went away as well. I am not sure if the two are related.

Any and all input would be highly appreciated.

Thanks so much!
Julie

[My_Roadtrek]

Bad Isolator.
Isolator

[drmopar]

Your unit may have a second battery that will charge when you start your engine. It is controlled by a relay when the ignition is on. If your batteries are low in charge, the relay and your voltage regulator will open and close relay. Just a thought. Had same noise in a Coachman MH.

[Liketoroam]

when the belt slips no charging In fact you get discharging. I ruined a battery trying to limp home when this happened.

[JulieB888]

Yes the voltage gauge does indeed indicate that power is coming in and is then cut off just as the click is heard and then comes in and is then cut off. For some time now, I noticed that when the engine charges the battery the charge doesn't last nearly as long as when it is charged with shore power. Maybe this is a problem that has been going on for some time and is worse now. Is it normal for the battery to react so differently to the two types of charging? I think the charge from shore power last three times as long.

[Liketoroam]

Check your voltage gauge when this happens. My 1999 would go up and down and I changed the serpentine belt and every thing worked perfect afterwards. being hard of hearing i didn't hear the slight squeak. Happened mostly when cold or damp outside

[JulieB888]

Hmmm interesting point about the circuit breaker. Maybe. The battery is very low. But is this explanation consistent with the lights dimming even when circuit breaker is good, and with the noise happening when the lights aren't on? And also the noise only happening some of the time, despite the battery being low all of the time?

The coach lights do seem to be intimitely connected to the noise however. I started the engine for the fourth time today. It ran for a few minutes without any noise. However as soon as I turned the coach lights on, the noises began. I turned off the engine and the coach lights then turned the engine back on and the noise began as soon as it started.

I am worried about going to an RV mechanic. First I'd have to drive more than an hour since I am camping in a forest and second, I am really worried about getting cheated. I wonder if I can leave it until it becomes clearer what the source of the problem is or if this is a dangerous idea.

Thanks for all your input!
Julie

[Lorne_Lorraine]

You may have a failing circuit breaker in the line that leads from the alternator to the coach battery. On a previous Class B I had such a breaker that would make clicking noises as it broke the circuit and then reset itself repeatedly. When it "breaks" the line the coach lights dim because they are only getting power from the coach battery. When the breaker clicks in again the coach lights brighten with the power coming from the alternator. A coach battery being low on charge or weak would exacerbate this situation. In addition to brightening the lights the alternator will also attempt to charge the coach battery at the same time. The resulting higher current in the line may be enough to trip a weak circuit breaker. The breaker in my unit was located right beside the battery.

[sch911]

Voltage Regulator

[midnightsadie]

bearing going bad in the alt.

[JulieB888]

No the defroster isn't running and neither is the AC. I just want to emphasize the the coach lights have always systematically dimmed - meaning dimmed and went back up, dimmed and went back up - when the engine ran, but now they are doing it in tandem with the click.

I will clean the battery teminals and check for loose connections. The noise didn't seem to be coming directly from the battery but some place close by. Very strange. I have started it 3 times today, and haven't heard it, but I am still worried.

[Fire19]

Check for a loose connection on the battery or clean the battery connections could be hearing arcing.

[ScottG]

Is the defroster running? Maybe it's the AC compressor running..?
That shouldn't dim the lights though unless battery or alternator is weak.