Garmin GPSMAP188C

DGR · 10 June 2007, 12:46

I've got one of these, and I've started to get intermittent satellite reception. It seems to just come and go, and it doesn't seem to be dependant on what I'm doing with the boat.

Having looked at the installation, the cable from the aerial goes into the engine box, where it is coiled round and zip-tied to keep it tidy, and then connected (via a BNC connector) to another lead which goes through the trunking and then up to the GPS unit.

I think that the problem is in the BNC connection in the engine box - the connector is quite corroded - so I want to change the connectors and then weatherproof/protect it properly.

Does anyone know whether the cable from the Garmin antenna is coax with a braided outer - or is it one of those foil ones that are a real pain in the butt?

Also - can anyone think of any other reason why the signal might be lost?

Ta!!

D...

jwalker · 10 June 2007, 13:00

In your case I don't know but if it's the aluminium wrap type, there should still be a piece of multistrand sink wire along with the foil. With a bit of fiddling, you will be able to catch this into the BNC connector. However, given that Garmin are using a BNC connector, I'd bet it's a braid inside there. It might have foil too but this can be ignored for connection purposes.

Let us know what you find.

chris123 · 10 June 2007, 13:39

Does the cable outer have any text printed onto it? If it has the letters 'RG' followed by a number (eg RG174, RG58) then this is the cable type, which amongst other things should define the properties of the screen.

You can then search for this cable type (eg at www.rswww.com) and get the full cable details. The RG number will also ensure you get the right replacement BNC connector.

HTH

Chris

DGR · 10 June 2007, 18:31

Thanks for that!!

Today the unit got no signal at all from the antenna - at least yesterday it was intermittant.

The cables are indeed both braded cable - so no problem there. However, the problem does not appear to be the connection!!

Before taking things apart, I connected the antenna BNC directly to the Garmin unit across the deck (missing out the extension lead completely) - and it still does exactly the same, no signal.

SO - I suspect (hope) that the antenna is malfunctioning, and not the GPS unit......

I'll test it with another antenna tomorrow to gauge how expensive the fix might be!!

D...

Pete7 · 11 June 2007, 13:37

Quote:

Originally Posted by DGR

Also - can anyone think of any other reason why the signal might be lost? Ta!! D...

Had three problems with our 188c over 3 years, first the BNC connection became loose and would undo itself so a gentle squeeze with the pliers solved that. Secondly it doesn't like low voltage. 11.2 volts would set off the alarms and wouldn't locate itself with less than 12 volts. Solution for us was to switch it to 24 volt supply as Garmin will run on 12 - 36 volts. You may have slight corrosion in the power supply wires which could be causing your problem. Final problem was complete failure, so Garmin replaced it with a new unit for free.

I have cut and re-made the sounder cable which is foil lined. Wrapped the foil back again and it works fine. Can you not mount the ariel next to the display unit, less cable, fewer joins etc

Pete

DGR · 12 June 2007, 15:07

It looks like its the unit that is at fault.

Everything works fine except that it can't pick up satellite signals. I've plugged in a new aerial direct to the back of the unit, and it still won't see anything - so it's not the aerial!!

It's not setting any alarms off or anything about power - and the sounder is working absolutely brilliantly, as are all the other functions. I therefore suspect that the unit is at fault.

SO - as the unit is 2 years and 9 months old - and now out of warranty (although I've yet to have a chat with Garmin support to see what they say) and now discontinued - I'm bracing myself for a replacement.

Looking at the various offerings, the one that will plug in straight away without any rewiring of plugs or changing of sounders/aerials etc is the GPSMAP 292/298. Does anyone know what the difference is between the two units? They appear to share the same manual - so it's a little confusing.

D...

jwalker · 12 June 2007, 16:37

From memory, I think the 292 doesn't have a sounder facility.

DGR · 12 June 2007, 18:02

Quote:

Originally Posted by jwalker

From memory, I think the 292 doesn't have a sounder facility.

Yes - you are correct!!

After an afternoon of reading online manuals and trying to work out the difference, it appears that the 292 can be integrated with the GSD21 sounder (another £100 ish) to give the same capabilities as the 298. I wish that it stated that more clearly somewhere!!

Right, next question... has anyone bought a Garmin GPS from the States - any pros (like it's half the price) or cons (not supported locally, trouble with getting maps and software updates to load or anything like that).

Also, do you think that my current map source memory card will 'plugnplay' with a new unit, or will I need to get another unlock code to work eith that unit?

D...

jwalker · 12 June 2007, 18:11

Quote:

Originally Posted by DGR

Right, next question... has anyone bought a Garmin GPS from the States - any pros (like it's half the price) or cons (not supported locally, trouble with getting maps and software updates to load or anything like that).

You've pretty much said it. I did and it was fine but I didn't need to claim any warranty so don't know how that would be.

Quote:

Also, do you think that my current map source memory card will 'plugnplay' with a new unit, or will I need to get another unlock code to work eith that unit?

If you purchased it as a pre-programmed card, it will be fine. If you wrote it yourself using mapsource, it won't work but you are allowed a second unlock free of charge from Garmin and you could use that on a new unit.

Pete7 · 13 June 2007, 11:01

Quote:

Originally Posted by DGR

Right, next question... has anyone bought a Garmin GPS from the States - any pros (like it's half the price) or cons (not supported locally, trouble with getting maps and software updates to load or anything like that).D...

I would have a chat to Garmin first, they replaced my 3 year old 188c with a new unit for free last month (although they did quote £126 exchange / repair) before seeing the unit, so they do have stock of the older models.

They have recently moved to a new very posh unit near Totton just outside Southampton BTW from Romsey, so check the address if you are sending it in to them.

Pete

DGR · 13 June 2007, 13:37

Pete,

Have you got a good number for them? The e-mail I got from Tech Support this morning is saying that I need to send it to the US to be repaired.

D...

Pete7 · 13 June 2007, 14:51

I just used the one on there web site. Did you buy it from the states then ?

Pete

DGR · 14 June 2007, 12:34

Quote:

Originally Posted by Pete7

I just used the one on there web site. Did you buy it from the states then ?

No - it came with the boat as new from Ribcraft - so I assume it was a UK sourced unit. I think perhaps the 'query' form I filled in on the web went to the US rather than the UK one - but I've found the UK number on the website and will give them a call and see how I get on.

Thanks for all the help!!

D...