I'm in the process of replacing the radio and while checking voltage I'm getting 15volts is this normal?
Checking it where, exactly. Under what conditions? Engine running, or off. Generator running, or off? Plugged in, or not?
Coach is plugged in, voltage was checked at the power sources going to the old radio. Old Sony will be replaced with a new Sony that has blue tooth, cd player usb port. Hope to have an easy install.
15v is a little high. With charger in bulk mode it should not be higher than 14.3-4 for AGM batteries. Maybe 14.6-7 for wet cells.
I'd check voltage at the batteries or even at the starter solenoid at the dash if you still have it open. If high there check settings for charger.
Would help if we knew a little more about your coach. What interverter/charger? What batteries?
see ya
ken
I understand lifeline only agms are 14.2 volts charge. The other brands are the higher number during charge. Something is wrong at 15 volts regardless of if charging or at float.
Ken I'm not at the coach but its a 95u320 with the original 2000watt inverter with 2 large gel batteries. Engine batteries are 3 Optima red tops.
Joe,
All voltages should be measured with a digital voltmeter. Dash analog is not accurate.
Radio voltage is probably coming from the engine batteries. The dash lighter plug is also from the engine batteries and the wall lighter plug is from the house batteries. Check your schematic. If in doubt, pull the engine battery ground cable to see if the radio wire still has juice.
As Ken posts, 15V is too high. Once the coach is plugged into shore power, the coach batteries if low should be charging at 14V plus. Engine batteries won't charge from shore power unless you have made a jumper like I did. Once the batteries have completed their charging, the voltage should drop way down or the batteries will boil and be ruined.
A full charge is about 12.7 volts with no charger connected. It should not be measured right after charging as the reading will be high and will not stabilize until at least an hour later.
When the batteries are finished the initial charging and on float/maintenance, the voltage should be between 13 and 13.5 volts. We have conventional engine batteries and six AGM house batteries and our reading are about 13.1 for both banks. The AGMs are going strong 9 years later. I just replaced the 3 engine batteries after installing new over 9 years ago.
Our OEM charger works fine but many owners have not been so lucky and have had their batteries boil from too high voltage. I check both banks by looking at the dash digital gauges every couple of days.
Pierce
Do batteries actually "boil" - or just look like they are boiling 'cause of the bubbles we see?
Jim
I have gone ahead and installed the radio. When I checked voltage I did use a digital voltmeter. When I did this the engine was off and I did have some other 12volt lighting on. I plan to run the engine tomorrow and will see what the voltage is with the engine running. Thanks everyone.
The bubbles you see are mostly oxygen. The electrolite (water and acid) is not really boiling. You can charge a battery at a fast rate but going over 125 degrees will damage them. The water will evaporate leaving acid well down from where the level is supposed to be and the case may swell. Read this as it's far better than I can explain here: BatteryStuff Articles | The Lead Acid Battery Explained (https://www.batterystuff.com/kb/articles/battery-articles/secret-workings-of-a-lead-acid-battery.html)
Pierce
As stated earlier I am changing out my radio. The old one was a Sony and the new one is a Sony. I have voltage to radio red wire and constant voltage also to the radio yellow wire. I have a ground which I checked for continuity. But when I plug into the new radio, I get nothing, any ideas?
Did you check the inline fuse on the power lead?
Do you have the speakers connected? Perhaps it won't come on without the speaker impedance load?
All speakers are wired antenna plugged in. This has me stumped. [pardon the pun Stump]
The new radios won't let you have power to the yellow wire it has to be switched. Fooled me also. Break the yellow connection and re hook it to test.
craneman I will try that. Thanks
Not all digital volt meters are accurate.
I have bought inexpensive volt meters and returned them after checking them with my known accurate Fluke meter.
I advise checking voltage with several digital volt meters and compare readings.
Wyatt I am using a Fluke meter.