Voltage Gauge and Multimeter Don't Agree

[Zeb1989]

Several weeks ago I removed fuel heater and plugged hole ( thank for the help found here ) now the voltage gauge reads about 14 1/2 while multimeter reads 13.8 on drivers side battery and 13.6 on passenger side battery. Is this because there is no fuel heater drawing current or somthing I should look for?

Thanks

 

[jim_22]

These are engine running numbers. The voltage gauge is likely reading the alternator output and there is a voltage drop between that and the battery because current is flowing through wires that have small but non-zero resistance. When your battery is fully charged as your numbers indicate the output current of the alternator is around 2 amps or so. These 2 amps going through 0.5 ohm of resistance cause a 1 volt drop between the alternator and your batteries. Just round numbers. Sounds normal to me.

 

[icanfixall]

The factory gauges never were anything more than an idiot light with a pointer. An example is the oil pressure or the coolant temp gauge. What does the r mean in normal as far as tmps go. Then there is the oil pressure gauge. Thats nothing to depend on thats for sure. I have run several diffeent aftermarket gauges for oil pressure. Some mechanical and some electric. Looking at the factory oil gauge its waving to be but.. My Isspro mechanical or electric gauge is steady as a rock. As for what you personally are seeing. I feel you may have some batteries that are slowly dieing. They are very close to recording the same voltage. Its bad batteries or the alternator is failing. Might be both but answer how old the battery set is and has anyone replaced just one battery? Reason you replace both batteries is the new and old idea. Think of a new battery compared to an old battery this way. You have 2 containers with water in them. Say thats the voltage. You have them connected by a hose at the bottom. As long as they both are at the same level they stay the same full or whatever it is. But lower one container and that drains the other one. Same with a battery. An old one sucks down the new one to the old battery level. For those that did not know any of this class dismissed and BTW.. There is a test tomorrow...

 

[Zeb1989]

Thanks