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Voltage in dash

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3K views 37 replies 6 participants last post by  LeonardoDaBenz 
#1 · (Edited)
Hi does anyone's R172 specific only can display the voltage in normal menu, as in scroll through?

1. Asking for R172 so if it exists I am searching the data card code for it.
2. Not interested in service or engineering mode display, etc. I want a feature, if it exists to be able to be access whilst driving like the the way you would the trip meter for example.
3. Reply facts pertaining to this car I drive only thanks in advance.
 
#33 ·
My Doodad finally arrived, I almost wrote it off as a China seller put on the extra cheap and slow boat, so after some long waiting since August 2021 about 12 weeks!! It was to my horror I discovered no matter what I did, the voltage stayed at 12.5 volts! I got suspect when there was no voltage drop during cranking, so I took the Doodad apart and discovered the voltage display was not a display but a fake LED bar made to just light up and shows 12.5!!! I mean how cheap and nasty can one get??? Cleaver but nasty to someone wanting a variable gauge ,so this was fake as rocking horse $h1t!!!
The reason i bought it was the price was the same as the permanent fixture ones, so I opted to go the temporary route enabling me if I wanted to use the cig lighter to pump up my tyres or my spare, or use an accessory still!!
Oh well, it looks like I'll have to instal an auxiliary cig lighter socket in the boot and make a more permanent voltage meter like the one Trev5 has.
To be Continued LOL!
 
#4 ·
Thanks, it is more and more looking like an external option, unfortunately if there is no standard option, so ridiculous as you can defiantly access it in service mode, so it can be physically done, we just need some brilliant coder to crack the dash.
 
#8 ·
Keeping an eye on the voltage is useful, but agree it's not available in the standard menu...
Pressing a few buttons before starting the engine can bring up this display:
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I've also used one one these, but have to be careful as some of these knock out the radio signal due to poor design...
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This is what I'm currently using, which includes fast USB charging which is also useful.
Though this conversion does have some caveats, but does look neater and allows the cubby hole cover to be closed:
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#14 ·
100% you are on the same wavelength, its that pre-start up I want to be able access during a drive, I'm sure that there must be a hack for it somewhere just seeing if any of of you guys knew.
Not sure what it is on the R172, but on mine I have two "hidden" menues. One on the original HU - "Engineering Mode" where I can get more details about the car and especially the HU, and one for the center dash, where I get all sorts of information, such as being able to put the car in "Dyno Mode" (no slip etc, but very fun :) ).
 
#16 ·
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This looks to be an awesome option until I can crack the dash, but would you believe mine has a spring loaded cover that would snap shut over it!! Just my luck!!!
I might see if I can remove the trap door without it breaking to replace it later or I'll try find something small and similar that has a slight shoulder to keep the trap door open. I really like yours it looks awesome!
I seen a few that look really bulky and if used cannot shut the sliding door over it.
Worst case I can just open the trap door when I need to see the voltage, might be good in the dark as I can still leave the compartment door open.
 
#20 ·
This looks to be an awesome option until I can crack the dash, but would you believe mine has a spring loaded cover that would snap shut over it!! Just my luck!!!
I might see if I can remove the trap door without it breaking to replace it later or I'll try find something small and similar that has a slight shoulder to keep the trap door open. I really like yours it looks awesome!
I seen a few that look really bulky and if used cannot shut the sliding door over it.
Worst case I can just open the trap door when I need to see the voltage, might be good in the dark as I can still leave the compartment door open.
The cubby hole cover is spring loaded, but should stay open or closed - "Fairly easy to change".....
 
#35 ·
@Turbo haha! Love the angry Emote..... Yeah but I had fun blowing it up, I initially removed the so called voltage display from the circuit board, to test it and then added some voltage, it started to work from about 2.5 volts, that's when I discovered it was fake as it lit up as 12.5 volts, so I did what anyone would do, gave it full song 12 volts and it blew up sending the fake 12.5 facia sky rocketing about 1 foot in the air! so satisfying.
I re-assembled the socket and now I have a plain aluminium sided double USB adaptor, without the fake display so all good!
 
#36 ·
So I'll update--mine fluctuates between 12.2 and 14.5 or thereabouts. The thermometer component, well that one is suspect--at times. I took out my instant read thermo to test when cold and the doodad is ~2o higher so I can live with that--only got that addition as a novelty.

As it's by necessity near the hot air vents, it'll read various temps--up to 35oC so far (the heat coming out of the vent) but as it's temp sensor is only a little antenna, I can't really blame it.
 
#37 ·
So just another update.
@Trev5 Mention for thanks
So I got sick of the temporary Cig lighter voltage guage and installed a USB-3 and USB permanent voltage meter and I can say having the ability to close the door now is awesome, I won’t look back and more than happy that this is permanently done although I did an extra step and got out the hot gun and glued a small 12 volt glass globe in there to run to the plastic light cover for inside the storage tray that dims with the rest of the car.

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