VHF radio blowing fuses

[Mei Mac]

I bought a new Standard HorizonGX2400E a few months ago. Wired it up, new antennae and cable, and it powered up and worked a treat.

A few days ago I noticed my alternator had started kicking out 17v. A few days later my lovely new radio wouldn't come on. Before I can even turn it on It blows the 6A glass inline fuse (supplied with the unit) . As soon as power is sent to the radio from my fuse panel, the glass fuse blows. I took the radio home and hooked it directly to a leisure battery and the same thing happens. Therefore no problem with the boat's electrics. No dodgy connections, no shorts.

I know for a fact that the polarity hasn't been reverse since it was working a week ago and now it doesn't, the wiring hasn't been changed.

I have read that inside these radios there is a reverse polarity diode, that can cause blown fuses.

Since the radio is still in warranty, my next step is to call Standard Horizon for advice but I thought I would also ask you guys for any advice/experience you may have.

 

[Slowboat35]

Firstly, if your alternator is putting out 17v there is a problem and you are likely to blow anything else electronic connected to it. Get it fixed before switching anything else on! This could be a regulator problem, a faulty battery or faulty/loose/poor battery connections, or any faulty electrical connection on the back of the alternator or it's wiring loom further back. If you've eliminated those the voltage regulator is suspect so take the alternator off and have it checked by an alternator specialist. They are readily found locally and the check should be just a few pounds.

Here is the relevant part of your circuit diagram, covering the circuitry between the power switch and the supply.
Reverse polarity will I think burn out (ie short circuit) diode D221 causing fuses to blow as soon as power is supplied. Such components cost a quid or so for a packet of ten.
Someone more expert will doubtless be along to identify a likely candidiate.

Shouldn't be too hard to identify and mend by an electronics-minded person. Doubtless SH will have a repair agency, but whether that is cost effective is another matter.

Good luck!

 

[Mei Mac]

Firstly, if your alternator is putting out 17v there is a problem and you are likely to blow anything else electronic connected to it. Get it fixed before switching anything else on! This could be a regulator problem, a faulty battery or faulty/loose/poor battery connections, or any faulty electrical connection on the back of the alternator or it's wiring loom further back. If you've eliminated those the voltage regulator is suspect so take the alternator off and have it checked by an alternator specialist. They are readily found locally and the check should be just a few pounds.

Here is the relevant part of your circuit diagram, covering the circuitry between the power switch and the supply.
Reverse polarity will I think burn out (ie short circuit) diode D221 causing fuses to blow as soon as power is supplied. Such components cost a quid or so for a packet of ten.
Someone more expert will doubtless be along to identify a likely candidiate.

Shouldn't be too hard to identify and mend by an electronics-minded person. Doubtless SH will have a repair agency, but whether that is cost effective is another matter.

Good luck!

View attachment 136789

Thanks for response and knowledge. Phew, good to know that the radio hasn't been fried. I suspected that it would be still alive otherwise it wouldn't blow fuses would it?

I've bought a new alternator, since the other one started to emit a hot smell. The new one is yet to be fitted, but immediately stopped using the old one when I noticed the 17v.

 

[Daverw]

SH have a UK based workshop, give them a call, they are very helpful.

 

[Mei Mac]

SH have a UK based workshop, give them a call, they are very helpful.

Super - thank you for your help.

 

[oldgit]

Protection is against amps or RP not volts........................ if lots of volts!
Usually most PCB components are designed to function function between 10V and 18v volts above that and they are toast ? .
As suggested speak to the importer but it may cost more to send off and repair than the unit is worth.
Many importers now do a " Send us your duff unit and we will replace with a refurbished unit" for both fast turnround and to make economic sense.

 

[Mei Mac]

Protection is against amps or RP not volts........................ if lots of volts!
Usually most PCB components are designed to function function between 10V and 18v volts above that and they are toast ? .
As suggested speak to the importer.

Thanks. It just seemed to much of a coincidence that the radio works fine then it doesn't at around the sametime as the voltage spike happened. But again, coincidences do happen!
It may be of course that a short has occurred somewhere behind the panel, connectors touching or whatever.

I'll contact SH this morning and see what they say.

 

[Slowboat35]

Protection is against amps or RP not volts........................ if lots of volts!
Usually most PCB components are designed to function function between 10V and 18v volts above that and they are toast ? .
As suggested speak to the importer but it may cost more to send off and repair than the unit is worth.
Many importers now do a " Send us your duff unit and we will replace with a refurbished unit" for both fast turnround and to make economic sense.

More volts pushes more amps so they're not entirely unrelated.

Who knows what sort of current a duff alternator is putting out? If it's got a rectifier problem or intermittent contacts couldn't it be showering intermittent AC into the system which might produce enough negative polarity to blow a diode? That's just surmise mind!

The advice online is strong on checking all electrical contacts, plugs and fittings from the battery onwards as loose connections evidently do cause alternators to do strange things.

 

[Refueler]

I have a Cobra VHF that was just over a year old - that after winter - just blows fuses .... strange thing is that the panel it mounts in - has a stereo car radio .... that started doing same at same time.

I put it down to extreme cold and possibly moisture inside that froze ???

One day I will give to local electronics guy to check out ...

 

[oldgit]

95% of the time its not the actual equipment that has got any problem, its the miles of wiring, the umpteen junctions plugs/boxes/connections/fuses etc that are usually the cause of electrical woes and then add the fatal addition ................moisture .
Even newish boats and their original installations are not immune.
Over the years merely add every boaters delight ,a few bits of chocolate block and the odd run of mower cable (seriously) or old lamp flex !
Spent ages on just about every boat have ever owned attempting to strip out mysterious bits of wire which seem to start and go nowhere and do nothing.
It would help if the builders colour coded ALL the wiring instead of using the same blimming colour and as for leaving bits of cord to assist in pulling through new cabling..........
.......................Guarenteed to jam immovably at the first pinch point/awkward turn.

 

[Mei Mac]

I bought a new Standard HorizonGX2400E a few months ago. Wired it up, new antennae and cable, and it powered up and worked a treat.

A few days ago I noticed my alternator had started kicking out 17v. A few days later my lovely new radio wouldn't come on. Before I can even turn it on It blows the 6A glass inline fuse (supplied with the unit) . As soon as power is sent to the radio from my fuse panel, the glass fuse blows. I took the radio home and hooked it directly to a leisure battery and the same thing happens. Therefore no problem with the boat's electrics. No dodgy connections, no shorts.

I know for a fact that the polarity hasn't been reverse since it was working a week ago and now it doesn't, the wiring hasn't been changed.

I have read that inside these radios there is a reverse polarity diode, that can cause blown fuses.

Since the radio is still in warranty, my next step is to call Standard Horizon for advice but I thought I would also ask you guys for any advice/experience you may have.

I had to send my radio to Standard Horizon in June, to get it fixed (they said there was an out of warranty issue and that they needed a new part from Japan). I still haven't received my radio back. Anyone else had long waits like this with SH? I'm at my wits end and have had to buy a hand held radio as a temporary measure over the summer.

 

[William_H]

What is not clear from OP description is if the unit blows fuses even when switched Off at the volume control. If it does with switch off then most likely one of the capacitors or the diode. The capcitors seem to be quite low capacitance value which usually means ceramic C so quite robust and reliable. The diode if you can identify it may have short circuited. Try just cutting one lead.
If the radio only blows fuses when turned on then my guess is that components have failed under high voltage and most likely radio is cream crackered. ol'will

 

[Mei Mac]

What is not clear from OP description is if the unit blows fuses even when switched Off at the volume control. If it does with switch off then most likely one of the capacitors or the diode. The capcitors seem to be quite low capacitance value which usually means ceramic C so quite robust and reliable. The diode if you can identify it may have short circuited. Try just cutting one lead.
If the radio only blows fuses when turned on then my guess is that components have failed under high voltage and most likely radio is cream crackered. ol'will

Standard Horizon have identified the problem and have informed me that the radio is ok but needs a new component (cost around £70).

My question was has anybody else had to wait 4 months for their radio back after sending it in for repair?

 

[oldgit]

Suspect SH have regarded your problem as not coming under their warranty terms.
That £70 is almost certainly a half hour fixed labour charge £30.00 ? plus what ever PCB board was changed, plus fixed £12.50 P&P and £14.00 VAT on top etc etc
..... no it should not take 12 weeks to get it back.
A certain company in Hernia Bay, Kent, who still repair radios that are decades old in their workshops , would be mortified if they took that length of time to fix something.

 

[PaulRainbow]

Protection is against amps or RP not volts........................ if lots of volts!

This is not correct. A diode will protect against over voltage, it will fail "closed", this will have the appearance of a short circuit and will blow as many fuses as you throw at it.

The diode if you can identify it may have short circuited. Try just cutting one lead.

I would suspect that the diode has failed short circuit, as above, due to the 17v passing through it from the alternator. In that case, your suggestion of cutting "one lead" would allow the radio to work, but would have removed any over voltage protection.

 

[PaulRainbow]

Standard Horizon have identified the problem and have informed me that the radio is ok but needs a new component (cost around £70).

My question was has anybody else had to wait 4 months for their radio back after sending it in for repair?

Chances are the component will cost about 5p, plus shipping from Japan and labour. But, at least they will fix it, other than SH and Icom, you probably wouldn't get a VHF fixed.

As for the wait, there is a Worldwide shortage of certain electrical components, affecting VHFs and AIS quite badly. It's also affecting many other things in different industries. I've always found SH service to be very good.

 

[Mei Mac]

Chances are the component will cost about 5p, plus shipping from Japan and labour. But, at least they will fix it, other than SH and Icom, you probably wouldn't get a VHF fixed.

As for the wait, there is a Worldwide shortage of certain electrical components, affecting VHFs and AIS quite badly. It's also affecting many other things in different industries. I've always found SH service to be very good.

Thanks for this which gives me some assurance that I'm not going to be waiting forerver!

 

[ProDave]

To get 17V your battery must be fried as well. Even an alternator trying to output 17V connected to a working battery, the battery would limit it to about 14V max. So check your battery is not dead or dry.

If the radio is new, claim on the guarantee, but best not to mention the 17V incident.....

 

[andsarkit]

This is not correct. A diode will protect against over voltage, it will fail "closed", this will have the appearance of a short circuit and will blow as many fuses as you throw at it.

If the circuit in #2 is correct the diode is only for reverse polarity protection. Even the cheapest diode would probably have a 100v rating. It would be better to use a power zener diode such as a Tranzorb TVS which would also provide voltage protection and be robust enough for the fuse to blow before damaging the diode. I always fitted 1500W ones on any PCB that might be subjected to voltage spikes.

 

[Spirit (of Glenans)]

Thanks for response and knowledge. Phew, good to know that the radio hasn't been fried. I suspected that it would be still alive otherwise it wouldn't blow fuses would it?

I've bought a new alternator, since the other one started to emit a hot smell. The new one is yet to be fitted, but immediately stopped using the old one when I noticed the 17v.

You could have brought the alternator to a firm that repairs and reconditions automotive starters and alternators. There's generally at least one in any decent-sized town. e.g. Auto Parts UK is one search result that crops up. There is a firm that does similar for "marine" starters and alternators, but these will be the same items at twice the price.i