Stock fuel level sender output V / wiring? Integration to AIM MXL??

[MikeE36]

Hey, just wondering if any of you guys have successfully configured / wired up your stock fuel level sender to work with a custom sensor table for an AIM MXL Pista.

I only have my stock dash in place for fuel level, and on my new build I'd like to totally eliminate it and just have the MXL, but I need fuel level. How does one tap into the wiring for the fuel level? Which connector is it, which wires? Anyone with just an aftermarket fuel gauge want to chime in on how they ran the wires to the gauge? I assume it is the left most connector on the stock cluster, but I am not sure which wires to grab. I am not opposed to just running an autometer fuel level gauge if no one has the voltage output table for the stock level sender.

Any help is greatly appreciated!

Thanks,
-Mike

[dallas02E39]

On the E36 it is not voltage but resistance the changes with the fuel level, which can be turn into a variable voltage. Brown/yellow is the sender and Brown/Black is the ground. It is close to 0 ohms empty and 260 ohms when full. None of the aftermarket gauges seem to have anything even close. I actually have the wires run near my center dash and use my ohm meter to check levels between runs. I have been working on a led light array that will show level based on the resistance.

Dave-

[sak335]

Correct, it is the Brown and Yellow wire. You need to solder a 100 Ohm resistor in parallel to this wire, then feed that into a 0-90 Ohm range aftermarket fuel guage. The above gives you a range of 0-72 Ohms which should be close enough.

I'm running an Autometer that you set up originally by pressing a button when the fuel is empty and full, using the above resistor. The meter then uses that range to determine fuel level.

[ScotcH]

I've used this in the past. Works well: http://www.cruzpro.com/tl25.html

[jjvincent]

http://www.apexspeedtech.com/phpbb/v....php?f=1&t=682

[cragg56]

Anyone running one of these? If so, can you send me the calibration data so I don't have to fill the tank to collect it. Thanks

http://www.ironcanyonmotorsports.com...el-sender.html

[ScotcH]

I just got a couple of those ... haven't hooked them up yet though! If you get to it first, post up your results.

[cragg56]

I shot bimmerworld an email. Hopefully they will send it my way if someone else doesn't

[markn91387]

If you have any issues or questions concerning the installation or the calibration process feel free to give me a call or email. I don't hang out here much so email/phone is best.

Thanks,

Mark
markn@ironcanyonmotorsports.com
Iron Canyon Motorsports
(800) 408-1390

[cragg56]

If you have any issues or questions concerning the installation or the calibration process feel free to give me a call or email. I don't hang out here much so email/phone is best.

Thanks,

Mark
markn@ironcanyonmotorsports.com
Iron Canyon Motorsports
(800) 408-1390

Mark. Do you have a calibration file for an e36 fuel tank and sensor so that I don't have to fill the tank a gallon at a time? Bimmerworld did not have anything.

[markn91387]

Sorry. I don't have a calibration curve for the E36. You could always calibrate in increments more than 1 gallon to speed the process up a bit. If anybody wants to send me their calibration data I'd be happy to host the data files and make them available for download. These senders have gone into every thing from Volvo's to Ferraris and I've never even thought of asking for a user to contribute their calibration files. I probably should have started doing this a lot earlier. It sure would make life easier for a lot of people.

Mark

[cragg56]

Sorry. I don't have a calibration curve for the E36. You could always calibrate in increments more than 1 gallon to speed the process up a bit. If anybody wants to send me their calibration data I'd be happy to host the data files and make them available for download. These senders have gone into every thing from Volvo's to Ferraris and I've never even thought of asking for a user to contribute their calibration files. I probably should have started doing this a lot earlier. It sure would make life easier for a lot of people.

Mark

I am surprised that you don't have a bunch of calibration files. Hopefully someone on here can help us all out.

[Steve J.]

Just empty your fuel tank, put a gallon in, look at live data on PC. Put 2 gallons in, read data, repeat. it doesn't take long and then you know you have a very accurate scaling for your specific car.

The ironCanyon setup works great.

[digitalseance]

Correct, it is the Brown and Yellow wire. You need to solder a 100 Ohm resistor in parallel to this wire, then feed that into a 0-90 Ohm range aftermarket fuel guage. The above gives you a range of 0-72 Ohms which should be close enough.

I'm running an Autometer that you set up originally by pressing a button when the fuel is empty and full, using the above resistor. The meter then uses that range to determine fuel level.

Sorry for bringing this back to life, but this seems like the best info from all my google-ing and forum searching...

I picked up this exact fuel gauge (Auto Meter 3310 Sport-Comp Electric Fuel Level Gauge). However I did not put a resistor in between the gauge input and the yellow/brown wire assuming (oops?) that since the just the passenger side sender read correctly.

I've got the ford v8 swap with a carb, so the electrics are fairly simple. I checked the passenger side sender and it reads ~10ohms "empty" and ~250ohms full. I verified that with the power on, the yellow wire into the passenger site sender does have continuity to the power source so its getting power (didn't measure how much). After calibrating the gauge using the yellow/brown wire, it reads error. Since I don't have an easy way to empty the tank again and I really don't feel like pulling out the sender/pump unit, I guess I'll have to try again after running through this tank. I will admit that it took me about 20mins or so to fill up the tank (they don't make 5gal gas jugs like they used to), and the directions never said to cut power to the gauge while filling so I didn't.

I'd like validation on my logic (or lack of knowledge) of how the system works. It appears there's a black/brown wire that goes to the drivers side sender, then a heavier solid yellow wire that goes from it to the passenger side sender. The other wire leaving the passenger side sender is a yellow/brown wire, which is what I attached my gauge input wire to (following quoted logic). This car is a 92 325is so there's only 1 "X" connector under the hood (M50 motor). The only wire getting power (relayed/fused) directly to the "X" connector is is the heavy green/violet wire which powers the fuel pump.

I'm assuming the yellow/brown wire coming out of the passenger side sender is the same yellow/brown wire that would be going to the OEM dash gauge. All that said, I've got a few questions...

-Is this really the right wire to directly wire to the input of the autometer gauge or do I have all this backwards somehow?
-Alternatively, do I need to pull the dash cluster and grab that specific yellow/brown wire only?
-What's the point of the resistor if the gauge supports 0-280ohms? (logic here is that only one sender's resistance is being read, not both?)
-Why can I not get an ohm reading from the outgoing yellow/brown wire when the power is on? (epic failure since this is supposed to go to the gauge?)
-Is there another wire at the "X" connector that should be getting power that would magically solve/help this issue?


TIA

[sab0276]

^Bump. Any more updates or info on this?

[=BA=]

As far as I have read the other posts BOTH of the senders are 280 ohm EACH.

So in that case the gauge you would have hooked on is not the right one. As when both resistors are in series, they will actually read 560 Ohm. So you need to see if there is a 560 Ohm gauge available. Otherwise

What these guys are doing on the MXL with the resistor in between is something entirely different. By adding a resistor and connecting the signal wire between the resistor and the senders, you are actually creating a voltage divider circuit, similar to a potentiometer. So the MXL guys can calibrate their dash against this signal.

[sab0276]

What these guys are doing on the MXL with the resistor in between is something entirely different. By adding a resistor and connecting the signal wire between the resistor and the senders, you are actually creating a voltage divider circuit, similar to a potentiometer. So the MXL guys can calibrate their dash against this signal.

This is actually what I want to do. I have a data logger I'd like to add fuel too. Will adding a resistor and hooking to a data logger mess up the stock fuel gauge reading?

-Scott

[=BA=]

Yes it will if you are trying to hook up both in that manner.