Voltage is low to some of my electronics yet my batteries are fully charges-gctid804828

[Guest]

Hello everyone, I have a Bayliner 340 SB 2008 with three batteries. They are new and take a good charge. Yet my Garmin VHF radio alarm goes off stating low voltage. I am getting 6.5 on average. We found a slightly loose ground deep inside the side of the hull to the starboard side of the helm. Upon tightening the bank of electronics got a full 12.5 and the VHF alarm stopped. Yet when I turned off the breakers to the batteries and then turned them back on the low voltage returns. Can anyone shed some light on this issue?

Thx

[2850Bounty]

If the voltage is up to snuff at the battery bank(s), yet it is low at the helm, you may have a continuity issue with either the Positive or Negative path.

In other words, if the power is there at the batt bank, yet is not fully making it to the helm, there is excessive resistance somewhere within these circuits...... either in the Pos or Neg path. As per what you have already done, check again all Pos and Neg connections.

Questions:

Are you using the boat's main helm harness to power these electronics?

Does this occur while either the SLBB or the HLBB is being selected? (SLBB = start load batt bank..... HLBB = house load batt bank)

By chance do you have an excessive amount of 12 vdc demands on the helm harness?

Have you examined the helm-harness-to-engine-harness interface connection? (in many cases, the helm harness receives it's power from the engine harness via this connector)

Have you tested the voltage at the rear of your 12 vdc breaker panel?

Have you tested the voltage at the actual circuit breaker terminal?

Does the breaker panel's Negative distribution terminal block offer good continuity?

IMO, our electronics should not be powered by the OEM helm harness. You will do much better if these are powered via fresh, dedicated and independent circuits (both Pos and Neg) that have been run foward from the engine bay.

The new circuit would now power the electronics, leaving the OEM helm harness powering the helm, cabin loads, instruments, etc. only.

Try to avoid any direct battery connections (other than your main battery Pos and Neg cables).

You can use the rear terminals of your MBSS for your Postive source.

Your engine will be your System Negative Common. Run a small cable from the engine block to a Negative terminal block for these.



.

[Guest]

Make sure the wires going to your electronics are of a proper guage especially if you have a bunch of electronics connected to the same circuit. I have this issue with my VHF which was also connected to the circuit going to my DSM and MFD. I changed the wire guage and the issue went away.

[JimMc]

"2850Bounty" post=804830 wrote:
[color]#000088 wrote:
If the voltage is up to snuff at the battery bank(s), yet it is low at the helm, you may have a continuity issue with either the Positive or Negative path.

In other words, if the power is there at the batt bank, yet is not fully making it to the helm, there is excessive resistance somewhere within these circuits...... either in the Pos or Neg path. As per what you have already done, check again all Pos and Neg connections.

Questions:

Are you using the boat's main helm harness to power these electronics?

Does this occur while either the SLBB or the HLBB is being selected? (SLBB = start load batt bank..... HLBB = house load batt bank)

By chance do you have an excessive amount of 12 vdc demands on the helm harness?

Have you examined the helm-harness-to-engine-harness interface connection? (in many cases, the helm harness receives it's power from the engine harness via this connector)

Have you tested the voltage at the rear of your 12 vdc breaker panel?

Have you tested the voltage at the actual circuit breaker terminal?

Does the breaker panel's Negative distribution terminal block offer good continuity?

IMO, our electronics should not be powered by the OEM helm harness. You will do much better if these are powered via fresh, dedicated and independent circuits (both Pos and Neg) that have been run foward from the engine bay.

The new circuit would now power the electronics, leaving the OEM helm harness powering the helm, cabin loads, instruments, etc. only.

Try to avoid any direct battery connections (other than your main battery Pos and Neg cables).

You can use the rear terminals of your MBSS for your Postive source.

Your engine will be your System Negative Common. Run a small cable from the engine block to a Negative terminal block for these.

[/color]

.

I will disagree with the very last sentence. Run a sufficiently large negative cable from the engine block to a negative terminal strip. From this negative terminal strip you can wire all of the negatives to your various devices.

[2850Bounty]

"JimMc" post=804851 wrote:

"2850Bounty" post=804830 wrote:
Last sentence> [color]#000088 wrote:
Run a small cable from the engine block to a Negative terminal block for these.

[/color]

I will disagree with the very last sentence. Run a sufficiently large negative cable from the engine block to a negative terminal strip. From this negative terminal strip you can wire all of the negatives to your various devices.

[color]#000088 wrote:
Jim, you are correct. I guess that I was refering to battery cable size in comparison.

A sufficiently sized cable is what I should have suggested.

.

[/color]

[JimMc]

"2850Bounty" post=804830 wrote:
[color]#000088 wrote:
If the voltage is up to snuff at the battery bank(s), yet it is low at the helm, you may have a continuity issue with either the Positive or Negative path.

In other words, if the power is there at the batt bank, yet is not fully making it to the helm, there is excessive resistance somewhere within these circuits...... either in the Pos or Neg path. As per what you have already done, check again all Pos and Neg connections.

Questions:

Are you using the boat's main helm harness to power these electronics?

Does this occur while either the SLBB or the HLBB is being selected? (SLBB = start load batt bank..... HLBB = house load batt bank)

By chance do you have an excessive amount of 12 vdc demands on the helm harness?

Have you examined the helm-harness-to-engine-harness interface connection? (in many cases, the helm harness receives it's power from the engine harness via this connector)

Have you tested the voltage at the rear of your 12 vdc breaker panel?

Have you tested the voltage at the actual circuit breaker terminal?

Does the breaker panel's Negative distribution terminal block offer good continuity?

IMO, our electronics should not be powered by the OEM helm harness. You will do much better if these are powered via fresh, dedicated and independent circuits (both Pos and Neg) that have been run foward from the engine bay.

The new circuit would now power the electronics, leaving the OEM helm harness powering the helm, cabin loads, instruments, etc. only.

Try to avoid any direct battery connections (other than your main battery Pos and Neg cables).

You can use the rear terminals of your MBSS for your Postive source.

Your engine will be your System Negative Common. Run a small cable from the engine block to a Negative terminal block for these.

[/color]

.

I will disagree with the very last sentence. Run a sufficiently large negative cable from the engine block to a negative terminal strip. From this negative terminal strip you can wire all of the negatives to your various devices.

[JimMc]

I knew what you meant. But others might have taken you literally.