Electrical question…..R80GS paralever

[Mad Hatter]

Question for any electrically minded chaps out there? I need a switched live to power the charging cradle for my garmin Montana. I know I can fit a relay triggered by a sidelight etc to create a dedicated supply, but as the garmin will only draw 2.5amps tops, could I just use the switched feed to the instrument bulb which is redundant on my bike as it has a acewell speedo fitted which doesn’t have separate instrument light. It looks like it could be a very easy solution but I don’t want to risk burning any wiring. Expert advice appreciated…..

 

[DrFarkoff]

Question for any electrically minded chaps out there? I need a switched live to power the charging cradle for my garmin Montana. I know I can fit a relay triggered by a sidelight etc to create a dedicated supply, but as the garmin will only draw 2.5amps tops, could I just use the switched feed to the instrument bulb which is redundant on my bike as it has a acewell speedo fitted which doesn’t have separate instrument light. It looks like it could be a very easy solution but I don’t want to risk burning any wiring. Expert advice appreciated…..

Personally I would just use that instrument light to trip a supply relay Reason being the wiring on your bike is X years old Tripping a relay is totally negligible current and you have a dedicated new feed should you need to fit anything else up front too

BUT also Is the Montana a 12volt or the inline reduced power to 5 volt type USB feed

A few "experts" regretted cutting wires and feeding some of the earlier 5v fed GPS a full 12 volt!!

 

[Mad Hatter]

Thanks Dr. The input voltage is 10-30v, no idea what the voltage is coming out of the little black box in the middle of the cradle wiring loom is, but I don’t plan removing it so there’s no problem there. I just checked the instructions for the cradle and the maximum current draw is only 1.5amps, but….the instrument bulb is only 3w, which if I’ve got my maths right would mean a current draw of 0.25amps, so the cradle would be pulling 6 x more power than the bulb. Probably best to do as you suggest

 

[Greg Masters]

Are you certain that you want a switched supply? The GPS will power off when you turn off the bike.

Even though they power up quite quickly, it's always a pain waiting and the display is never on the page you want!

 

[Mad Hatter]

Are you certain that you want a switched supply? The GPS will power off when you turn off the bike.

Even though they power up quite quickly, it's always a pain waiting and the display is never on the page you want!

The Montana has an inbuilt battery so it can stay on when the bike power cuts out. When the bike switches off it gives you an option to stay on or switch off, and 30 seconds to make your mind up!

 

[Joe Bar]

Anything you can charge via a USB (std, mini, micro, c, etc.) has a 5v operating voltage. The black box on the cable is the voltage dropper. Never cut them off.

 

[mikeyboy]

You should have a white round connector in the binnacle,
This is used for the accessory pods sometimes fitted(tacho/clock)
You could tap into to acc feed there with no problem.
If you wanted to make a tidy job without messing with the wiring,
The mating connector is available from qtech

Rev Counter Plug with Contacts - Q-TECH

P/N: 725.13 Rev Counter Plug including contacts for all G/S, GS made from 1987-'90 and Basic. Fits the existing rev counter plug. This plug lets you connect all basic functions (on-board voltage, ground and rev signal) on electronic speedometers. Contains plug housing and contacts.

q-tech-shop.de

 

[mikeyboy]

Also,if you decided to fit a relay,
The spare connector on the ign switch is +ve

 

[Gelandestrasse]

Echo Mikeyboy - but I found this item on ebay which fits perfectly, too. https://www.ebay.co.uk/itm/132968760102 a bit cheaper and in UK (although all made in China no doubt).

 

[Pukmeister]

If you fit a relay triggered by switched live, be sure to use a cable sizing on the power circuit that can handle other loads. That way, if you want to add other switched feeds in future for other accessories, you can simply take it from the relay with confidence rather than having to add more wiring.

 

[Mad Hatter]

Thanks everyone for the info, I’ll take a peek inside the binnacle tommorow and see what I’ve got.