GARMIN 740S

[Gianni]

Hey guys hope all is well.


I have a garmin 740s...Last year worked well...This year went to power unit on and wont turn on... There is power to the fuse, any other possibilities?


Appreciate the help

 

[DennisG01]

Which fuse are you referring to? Bracket or flush mount? Sure you held the power button down long enough?

 

[Gianni]

Hey, im pretty sure i held down the power long enough.

The twist fuse that comes right before the machine tested for power.



Thanks for response

 

[SkunkBoat]

You checked at fuse. What about at plug in back of unit?

I have had problems with "green" pins in that connector in the past.

 

[Gianni]

The green pins on the machine or on the harness wire?

Unit was fine last year, so confused.

 

[SkunkBoat]

Generally, things always worked before they don't work....
Number one question of troubleshooting is "What did you do in between when it worked and when it didn't?
Rule out that first.


By "green" pins I mean "green corrosion".

Look at the connectors to the unit. Sometimes just taking them off and putting back could make it work.
Try electronic contact cleaner spray.

Check for +12v on the connector. Check the 12v negative (ground) on the connector. Your manual should show the pins for these.

If you have +12 v on the connector and a good ground connection(to 12v negative) and it doesn't work then you probably need to have it serviced by Garmin

 

[Denko]

Yep, check the female side of the connector. The Garmin I have goes out once or twice a trip, I think just a poor design. If you look close at the terminal it's a clamshell and it just spreads out over time I guess. Good luck!

 

[DennisG01]

You pulled the fuse out to check 12V+? Double check the fuse - those little ones are tough to tell, sometimes? As others said, check for the 12V+ at the lug end (the part that plugs into the machine. If there's no markings, don't worry - you won't do any damage if you probe the wrong hole. Connect the negative to any good ground (doesn't have to be the plug on the machine). If you have a bracket mount, this is all much easier, of course. As others said, sometimes just unplugging and replugging does it - make sure it's tight, too. A little bit of corrosion inhibitor is never a bad idea.

Do the same checks for the ground pin in the plug - being sure it's solid all the way back to your ground bus. If you verify 12V+ and Ground are good at the plug, then the problem is the machine's plug or the machine, itself.

 

[seasick]

I suspect that the unit may have died but to be sure you need to not only test for 12 volts at the fuse but also check that the ground is good. I suggest that you remove the unit and wire it directly to a good 12V dc source and see if it boots. If you have a friend with a similar unit ( actually similar power connector) ask if you can try plugging in your unit. That will elimination a bad power cable.
Checking the connectors for corrosion is also a good idea but the female connectors are no that easy to clean or to inspect. Remove and insert eh power connector a half dozen times to see if that makes a difference

 

[Gianni]

I will look into all these tips you guys gave me and post an update. Thank you all

 

[Gianni]

Harmon is sending me a test cable. They don’t service these units anymore. Too old now