voltage drop across gauges question

[1216bandit]

My volt meter reads low but I am showing 14 volts at the battery. I checked the voltage with a meter at the gauge and it read about 10.5. The volt gauge is the 4th gauge down from the ignition switch and voltage got higher at the other gauges as I moved closer to the switch. I am no electrician and am open to suggestions. The gauges are in a sealed dash..not open to the elements everything was clean and dry.
Thanx...Dan

 

[bruceb58]

Re: voltage drop across gauges question

Assuming your voltage gauge is accurate, you likely have a voltage drop between the battery and your helm because of the load that happens when you turn your ignition on. The voltage drop can be in either the positive or the negative leads form the battery.

First measure the voltage at your gauge to verify the gauge.

If that's still low, measure the voltage drop by getting a long test lead and measure the voltage between the positive terminal of the battery and the positive terminal of your gauge.

Do the same for the negative to negative. The voltage measured is supposed to be very low but you have 3.5V of drop somewhere.

 

[1216bandit]

Re: voltage drop across gauges question

The voltage showing on the dash mounted volt gauge was 10.5 verified by my test meter. The dash gauges are daisy chained and as I tested the other gauges working towards the ignition switch, the voltage at the gauges increased the closer I got to the switch, verified by the test meter. I will run the tests you suggested tomorrow morning. Thanx for the reply!

 

[bruceb58]

Re: voltage drop across gauges question

I tested the other gauges working towards the ignition switch, the voltage at the gauges increased the closer I got to the switch, verified by the test meter.

The only explanation for that would be that a load was attached at the end of that chain which shouldn't be there.

When you make these measurements at the dash, make sure you use the same ground reference for all your measurements. The ground at the fuse block would be a good place.

Also, measure the voltage at the fuse block itself where the wire comes from the engine compartment. Again, use the ground at the fuse block for your reference.

 

[1216bandit]

Re: voltage drop across gauges question

Thanx again for the tips....gonna tell the boss to give you a raise! I will do the tests tomorrow and post back with results

 

[tanker1983]

Any results of these tests to post? My volt gauge is reading 13.5 (guage only) when idling. Voltage on gauge drops to 12.3 when RPM go up.

Battery reading with engine off is 12.60v. When idling is 14.5 and at 2000 RPM is 14.7.