996 GT3 fuel tank resistances/wiring
#1
996 GT3 fuel tank resistances/wiring
Does anyone have the fuel tank resistances for the 996.2 GT3? I'm trying to set up fuel level in my car via the AiM MXS dash.
Also, does anyone have a wiring diagram for the 4-pin connector on top of the fuel pump? The big wires seem to be power and ground, and I suspect that one of the other 2 wires provides fuel level that goes to the stock dash, but not sure which one it is...
Also, does anyone have a wiring diagram for the 4-pin connector on top of the fuel pump? The big wires seem to be power and ground, and I suspect that one of the other 2 wires provides fuel level that goes to the stock dash, but not sure which one it is...
Last edited by T3C; 10-30-2023 at 11:53 AM.
#2
Rennlist
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It’s the violet wire. I take it at the cluster end but it’s continuous to the cluster from here.
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#3
Thank you! Do you also happen to know the resistance values for the tank and/or have a fuel table for the 6.2 GT3? If I can't find a fuel table then will have to figure out which resistor wire I will need.
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T3C (10-30-2023)
#6
I was told that I need to find the resistance of the stock fuel tank in order to figure out what kind of resistor I need... Which resistor do you use for a 6.2 GT3 tank?
Is it linear? I was under the impression that it wasn't based on some posts in the cup car forums.
Is it linear? I was under the impression that it wasn't based on some posts in the cup car forums.
#7
It's not linear...It's been awhile since I did the Iron Canyon gadget on my 996.2 cup but I do recall that. I just added a gallon at a time and measured the resistance after each gallon was added...did this from empty to full and it was amazingly accurate once i go it to "talk" o my AIM dash.
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ProCoach (11-02-2023)
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#8
It's not linear...It's been awhile since I did the Iron Canyon gadget on my 996.2 cup but I do recall that. I just added a gallon at a time and measured the resistance after each gallon was added...did this from empty to full and it was amazingly accurate once i go it to "talk" o my AIM dash.
#9
I do have a voltmeter, too. Do I just tap into the the purple wire on the fuel pump harness and measure the resistance after filling the tank completely?
#10
Rennlist
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From: Durham, NC and Virginia International Raceway
It’s not linear, that’s why you need to measure and create a sensor curve, for each gallon. Also taking into account the fuel that can’t be picked up as the floor.
#11
Per AiM instructions via the below PDF: “To correctly dimension the pull up resistor measure the two resistor values: with the fuel tank full and
with the fuel tank empty. Multiply the highest value by 9 to obtain the pull up resistor value to be used. In case this value is not available on the market choose the first round up value.
Example: if the float indicates 126 Ohm with the fuel tank full and 25 Ohm with the fuel tank empty, take 126 Ohm, multiply it by 9 and you get 1134 Ohm. Such a pull up resistor is not available on the market so choose a 1200 Ohm 1/4W resistor (very prudential power value) with a 5% precision.”
https://www.aim-sportline.com/downlo...el_100_eng.pdf
#12
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Sounds clear to me. Take the measures and do the calculation. The measures won't change (from top or bottom) but you'll get your needed information. If I had a 996 Cup, I'd do it for you, but you have one and you have the right tools.
#13
Looking at the picture of the fuel pump harness in one of my earlier posts—is the purple wire the correct one to tap into?
I’ve also never purchased a pull-up resistor. Where is a good source to purchase them? Could you possibly share a link?
#14
Rennlist
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From: Durham, NC and Virginia International Raceway
Yes. Purple is the signal lead.
Mouser is good. https://www.mouser.com/c/passive-com...ion-resistors/
Mil-Spec Wiring is where I go. https://www.milspecwiring.com/search...word=resistors
Mouser is good. https://www.mouser.com/c/passive-com...ion-resistors/
Mil-Spec Wiring is where I go. https://www.milspecwiring.com/search...word=resistors
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T3C (11-05-2023)