540c hardwire issues

misfit

Well-Known Member
I installed a 540c in my buggy for the KOH race and if the gps is on and i start the buggy it shuts off. I do have it hardwired right to the battery thru a fuse. Someone mentioned a capacitor on another site. What are you guys doing and are you having the same issue?
 

DBMETALWORX

Well-Known Member
Yeah ive had the same problem in my jeep.. Whats the deal???
 

clogking

Well-Known Member
What size Battery are you using? How many Amps does the starter draw? Seems you are using all the available power to start the car. On a side note the antennas on all new GPS's use power all the time. Just learned that after chasing a draw on my 1600.If you install the power supply as suggested from PCI it will slowly drain the battery unless you have it on a main battery cut off switch.
 

trent06

Mush
I have the same problem in our stock full and pre-runner, but I never thought it was a problem....? Just turn it back on and it works fine....
 

misfit

Well-Known Member
I have the same problem in our stock full and pre-runner, but I never thought it was a problem....? Just turn it back on and it works fine....
What about waypoints dont they get lost when that happens? Thats why i always have to turn it off my self so it saves them. I also hate when i forget to turn it on and drive about 5 miles and then im missing part of my course.

I am running a 1000 ca red top optima and the starter is a stock starter for a v6 vortec.
 

Tipracer

Well-Known Member
It might be that as you crank the engine over the voltage at the battery is falling below the on requirements of the GPS, could be a sign of a weak or dying battery. We have ours hooked up directly to the battery with a swich in line, I do not recall having this problem.
 

trent06

Mush
What about waypoints dont they get lost when that happens? Thats why i always have to turn it off my self so it saves them. I also hate when i forget to turn it on and drive about 5 miles and then im missing part of my course.

I am running a 1000 ca red top optima and the starter is a stock starter for a v6 vortec.
Hmmmm....We have never had any problems losing any of our ways points when it restarts, or the PCI download we get at the races....So I am not sure...

We use a motorcraft battery that you can get from any Ford dealership...
 

Bajades

Well-Known Member
I installed a 540c in my buggy for the KOH race and if the gps is on and i start the buggy it shuts off. I do have it hardwired right to the battery thru a fuse. Someone mentioned a capacitor on another site. What are you guys doing and are you having the same issue?
Your GPS is shutting off because at cranking your voltage is dropping below 10 volts. Even if the voltage only dips below 10 volts for a fraction of a second, it will shut down the unit. You will not lose any waypoints or tracks, but it might reset your trip meter (if you display that on the screen). Solutions include cranking with your battery selector set to both (on dual battery installations), larger starter cable, or a higher starting current battery.
 

Co-Dog

Well-Known Member
I ran into a similar problem and it turned out to be a voltage drop problem. The negative wire of the power cable was not getting a good connection (it looked like it was fine). If I remember correctly, the unit will continue to operate down to about 6 volts, but a little bit of resistance at the connection points becomes a big deal when the voltage gets down that low, as can happen when cranking the engine. It may also be a problem with the cables from the battery to the starter and to the chassis. To much resistance there will cause the voltage to drop unnecessarily when cranking.
 

y2kbaja

Well-Known Member
What get's lost when the unit powers off is the current trail, trip meters etc. This became a problem in the race car when we would have a side bet on top speed or average speed during the race. Once the unit is powered up it will continue the route you're on but the "bread crumbs" from the last power off are lost. I too would like to know the solution. On my old prerunner I'm sure it was a power loss due to too small battery cable from the back of the truck to the front but the same gps on the race car and it would do the same. I will be hooking the gps up in an 05 Tacoma in a few days with factory stuff straight to the battery, we'll see what happends there.
 

misfit

Well-Known Member
Hmm im still at a loss. I figured it was voltage drop but everything on this buggy is new and i ran large cable to the starter. I will check my connections again. And if i figure out my problem i will let ya know. Thanks for the help!
 

clogking

Well-Known Member
I will be hooking the gps up in an 05 Tacoma in a few days with factory stuff straight to the battery, we'll see what happends there.
Remember that the GPS antenna consumes a modest amount of current all the time!! whether the GPS is on or not.
 

Bantle

Well-Known Member
I started a new thead yesterday about the same problem without knowing this was already being discussed. I have both a 540c and a 7200 wired to the same power source in the truck however, only the 540c turns off when starting the engine. I was thinking it was a voltage problem but why would only the 540c turn off and not the 7200? Very confusing.
 

Bajades

Well-Known Member
I started a new thead yesterday about the same problem without knowing this was already being discussed. I have both a 540c and a 7200 wired to the same power source in the truck however, only the 540c turns off when starting the engine. I was thinking it was a voltage problem but why would only the 540c turn off and not the 7200? Very confusing.
The reason that the 540C shuts off and the 7200 does not is because the 540C has a threshold voltage of 10 volts and the 7200 will run on down to 9 volts. During cranking your voltage is momentarily dropping below 10 volts.
 
Top