Jump to content

 

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Sign in to follow this  
josh_tn

Voltage drop

Recommended Posts

josh_tn

I seem to be having a low voltage problem at the dash of my bu. I have checked the voltage with a DMM at the battery and everything seems fine. I get around 14 volts there. But at the dash, both voltage gauges(analog gauge and PP gauge) read about 2 volts lower. When I have more than 1 accessory running the voltage drops and the 'low battery' light on the dash lights up and my PP display sometimes dims. Even when I am not using any accessories, the most voltage I ever get at the dash with the boat running is around 11.6 V. I'm assuming that it could be a wire that is either not large enough or gotten pinched somewhere. My question is in troubleshooting to find the culprit. I have a meter but what is the best way to isolate the trouble? At the battery end, the only 2 things I can isolate are the 2 amps in the boat. Everything else seems to run off of one large wire going to the engine first.

I just installed dual Optimas but the problem was there even before I did and I noticed the problem the first time I took the boat out a couple of months ago. Any help would be greatly appreciated.

Josh

Share this post


Link to post
Share on other sites
M3Fan
I seem to be having a low voltage problem at the dash of my bu. I have checked the voltage with a DMM at the battery and everything seems fine. I get around 14 volts there. But at the dash, both voltage gauges(analog gauge and PP gauge) read about 2 volts lower. When I have more than 1 accessory running the voltage drops and the 'low battery' light on the dash lights up and my PP display sometimes dims. Even when I am not using any accessories, the most voltage I ever get at the dash with the boat running is around 11.6 V. I'm assuming that it could be a wire that is either not large enough or gotten pinched somewhere. My question is in troubleshooting to find the culprit. I have a meter but what is the best way to isolate the trouble? At the battery end, the only 2 things I can isolate are the 2 amps in the boat. Everything else seems to run off of one large wire going to the engine first.

I just installed dual Optimas but the problem was there even before I did and I noticed the problem the first time I took the boat out a couple of months ago. Any help would be greatly appreciated.

Josh

It is very possible that this is a grounding issue. What you could do is take a lead from the ground on the battery directly to the ground on the volt meter in the dash and see if it goes up. If it does, run another ground into the dash or look for loose ground connections. If that doesn't work, you could do the same with the + side of the battery to the + side of the gauge. Then the hot side is your culprit. That would be a good start. Could be many things.

Share this post


Link to post
Share on other sites
Sunsetter95

Check for loose connections on the wires also (the connector itself on the wire). If they have been loose for a while, there could be some corrosion or residue buildup on the wire. Check your batt cable ends for any corrosion at the wire insulation and where the wire goes into the terminal connector.

It sounds like M3Fan said, a loose wire, or too small of wire to handle the load.

Try a temp wire. It's fast and easy. Try it from the batt first, then from the starter terminal. Make sure you are ventilated well, there may be a spark when you touch the wire.

Share this post


Link to post
Share on other sites
67rway

You've got some great input above. Most likely a loose/bad connection.

From there I'd start isolating circuits by disconnecting them at the breakers, starting with anything aftermarket. Stereo, amps, heater, shower, cig lighter, etc. Doing them one by one should help determine the culprit.

Share this post


Link to post
Share on other sites
josh_tn

Thanks for all the great info guys. I hope to get out this weekend and try and isolate the problem. I'm having trouble understanding the wiring in the boat. When I was installing the dual batteries I noticed that there is a single large gauge wire that goes from the battery to the starter(I think its the starter). From there I assume there is some type of distribution block or fuse block somewhere that splits out to the alternator, accessories, engine, etc. Is there anywhere that I could find a wiring diagram of how the wiring is mapped out?

Share this post


Link to post
Share on other sites
OldHickory

All of the above suggestions are good. One more thing to try and I would start with this first. Turn on as many things as you can and using the dmm measure from the battery terminal to the connector itself. If there is corrosion there you will get a voltage on the meter. If so, disconnect the wire from the battery and clean the battery terminal and the connector with emery cloth then repeat the test after reassembling.

OldHickory

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...