Westerly Fulmar VHF power feed

[FulmarJeddo]

Following on from my thread where I was having trouble transmitting due to low battery charge, I have been doing some more investigations. Whilst my domestic batteries are currently under charged (I have disconnected the VSR that was putting a permanent load on the batteries), I did some checks with my voltmeter. When I transmit I see a volt drop of about 1 volt at the batteries. At the radio the voltage drops by about 2 volts and I get a low power warning on the display. It looks as though I need to replace the power cable. However, I can't find where it is connected at the battery/power unit end.

Are there any Fulmar owners out there that have had to do replace their's?

The power to the radio goes off when the isolator switches are turned off, but I can't find a fuse or breaker that feeds the radio. If I switch all the switches off on the power panel the radio remains live and there doesn't appear to be a breaker on the panel specifically for the radio. I can't trace the cable as it disappears into the paneling in the small locker in front of the chart table.
I wondered about shorting it out to see if anything tripped, but decided against that in case it was fed through a fuse and I couldn't locate it. I may end up just running a new cable via an inline fuse.

My Fulmar is one of the last 32s built in 1991 and has a different power board to the earlier boats.

 

[lpdsn]

The 1V drop at the batteries worries me more than the voltage drop over the wiring (although the latter is also significant). What current does your VHF take? My SH Gx2100 manual says it takes 5A when transmitting at hi power (25W). I can only presume yours is drawing significantly more, or you've got problems with both your batteries and wiring.

In terms of the wiring problem, look for dodgy/corroded connections along the way and sort those out. Try to find out if the voltage drop is mainly on the +ve or -ve wiring.

The one bit of good news is that it should be easy to trace the wiring as all you have to do is put the voltmeter on the presumed connector and transmit, and the voltage drop will confirm you've got the right wire.

 

[Bilgediver]

Were you measuring the volt drop by connecting the test meter to he battrery posts or were you reading the battery meter.

 

[Alpha22]

I suspect, with a volt drop like that, your battery is on it's way out. (Assuming, measured at the battery with an accurate meter)
Typical characteristics of a dying battery.... charges, although slowly. Appears fully charged, lights and small loads work OK but as soon as you put a serious load on it (25W x 12V = at least 2 amps) the battery is incapable of supplying the load.

 

[FulmarJeddo]

I think the batteries are ok. One is only just over a year old and the other was new this year. They desperately need charging, but seeing as I am on a swinging mooring I will have to rely on the solar panel topping them up. I made a mistake and connected a VSR across the two domestic batteries that has put a permanent load on both with the intention of it sharing the solar input. I didn't consider that the relay was going to be taking a load 24hrs a day. I have today removed the VSR and put the dual output from the solar controller across the two domestic batteries. Last weekend I was sailing with the fridge on and autopilot working hard, and found I couldn't transmit on the VHF. Today I didn't expect to find the batteries up as there hasn't been much sun in the last week. With the batteries in a poor state of charge I wasn't surprised to see the voltage drop on the batteries, but I didn't expect to see the much larger drop at the radio connector. The problem I have is I can only get to the connector where the radio lead connects to the boats permanent wiring and can't find where the cable is fused or connected to a circuit breaker to investigate that. The radio is a SH GX1500 that works fine when the engine is running.

 

[lpdsn]

I think the batteries are ok. One is only just over a year old and the other was new this year. They desperately need charging, but seeing as I am on a swinging mooring I will have to rely on the solar panel topping them up.

If it were me I'd get the batteries fully charged with some urgency. Really, seriously consider a night in a marina just to plug into shorepower. It'll be cheaper than new batteries. And set up a regime as soon as you can to keep them fully charged. Draining them as far as you have is not good for them and leaving them for a while so depleted runs the risk of a more permanent effect.

You should be able to find an SH Gx1500 manual on-line, if you haven't already. I wouldn't be the least surprised if the maximum current draw is the same as the Gx2100, so for 5A to have that effect there are currently serious issues with the batteries, never mind the wiring.

To put it into context, my two 7 year old batteries occasionally dip below 11V towards the end of a day's sailing when running an electric winch, but as the winch draws well over 100 Amps that's not exactly surprising.

 

[halcyon]

A little negative help, doing a quick check and all the panels we supplied Westerly none of them had a VHF feed.

Remove the main feed power feed at the switch panel, if the VHF remains it's not through your switch panel either, if it remains on your through the panel.

To check volt drops, get a length of 1 sq mm cable around 30 foot long, strip back insulation one end and twist tight around multimeter net probe, wrap insulation tape to hold in place. Remove main battery negative terminal, strip other end of wire, refit terminal with wire trapped between post and clamp. You can now measure voltages anywhere on the boat to a common zero point. Thus by checking along a cable run, even in the bow, a positive fault is shown by falling voltage, say battery is 12.6 volt, a fault will give 12.1 volt after fault point. Equally, a fault in negative cable is shown by a rising voltage, say 0.1 going to 1.2 would indicate a negative fault.

With power on and switch panel power disconnected, by checking any cable you should be able to find live cables and VHF route.

The above set-up can be used to check the charging system for volt drop, as yours does not sound to be correct, and your volt drop in VHF could be a charge related.

Brian

 

[FulmarJeddo]

A little negative help, doing a quick check and all the panels we supplied Westerly none of them had a VHF feed.

Thanks Brian for checking that. It seems a bit odd that they built a cable in with no protection, as I can't find any fuses, I may have missed something. Mind you, I couldn't find any 2 core cables around the batteries or terminating in the box above the engine either. I will try the long length of cable once I get the charge up on the batteries, it may just be charge related as the radio is fine with the engine running. I didn't check what voltage I was getting at the radio with the engine on.
David

 

[Alan ashore]

My recollection is that my (1983) Fulmar had a VHF supply cable running directly from the back of the (1-2-both) isolator, via an inline fuse near the radio itself.
There used to be a prevailing view that the radio power should be wired as directly as feasible, bypassing switch panels. My impression is that the present generation of builders, installers and owners are more generally in favour of switching and protecting the radio in the same way as everything else.

 

[halcyon]

Thanks Brian for checking that. It seems a bit odd that they built a cable in with no protection, as I can't find any fuses, I may have missed something. Mind you, I couldn't find any 2 core cables around the batteries or terminating in the box above the engine either. I will try the long length of cable once I get the charge up on the batteries, it may just be charge related as the radio is fine with the engine running. I didn't check what voltage I was getting at the radio with the engine on.
David

We fitted 4 breakers with no switch, so it is possible they connected to the aux power out put, disconnecting switch panel feed cable will indicate this


Brian.

 

[FulmarJeddo]

My recollection is that my (1983) Fulmar had a VHF supply cable running directly from the back of the (1-2-both) isolator, via an inline fuse near the radio itself.
There used to be a prevailing view that the radio power should be wired as directly as feasible, bypassing switch panels. My impression is that the present generation of builders, installers and owners are more generally in favour of switching and protecting the radio in the same way as everything else.

Thanks, I have the isolators with the big red keys. I'm pretty sure it's not connected there, I have had a good look around there. I will probably end up connecting a new cable, with in line fuse to the isolator switch.

 

[FulmarJeddo]

We fitted 4 breakers with no switch, so it is possible they connected to the aux power out put, disconnecting switch panel feed cable will indicate this


Brian.

When I was looking on Monday, Im pretty sure there was the same number of breakers as switches, I may be wrong. I will disconnect the feed and see what happens. Thanks.