Here's my situation:
Gas gauge doesn't work. Always reads full, and will once in a great while indicate actual fuel level (at least what I'm assuming is actual fuel level) but only once a month or something. Low fuel level light DOES seem to work.
I have an 1988 325is, it's got two fuel level senders. I pulled both of them out individually and checked the resistance, first right side up and then upside down to simulate full tank. The passenger side sender went from about 2 ohms to about 60 ohms. The driver's side went from about 50 ohms to about 150 ohms, although it seemed slightly sporradic. I looked up what they're supposed to be, and from what I could find, people say they should both be 0-60 ohms.
Now when I hook the brown/green wire that goes from the gauge to the drivers side sender straight to ground, it pins the gauge above full, and when I disconnect it, goes to below empty. Then I hook up a 1K resistor and it gives me 1/2 tank almost exactly. If a completely empty tank gives me a total 120 ish ohms resistance (according to the numbers I resarched) and completely empty off of my two measurements gives me about 210 ohms, I should get a similar result if I bypass the two senders and use about 220 ohms in resistors, which is what I did, and it BARELY moved the needle off of full.
Hope I haven't left out anything important.... but what I'm feeling like is that either the gauge is reading incorrectly, or there isn't enough resistance from one or both of the sending units when the fuel level gets low.
Anyone see some flaws in my testing or logic? Anyone know if the values I've found for the two senders are totally off?
Thanks in advance for any help!
Gas gauge doesn't work. Always reads full, and will once in a great while indicate actual fuel level (at least what I'm assuming is actual fuel level) but only once a month or something. Low fuel level light DOES seem to work.
I have an 1988 325is, it's got two fuel level senders. I pulled both of them out individually and checked the resistance, first right side up and then upside down to simulate full tank. The passenger side sender went from about 2 ohms to about 60 ohms. The driver's side went from about 50 ohms to about 150 ohms, although it seemed slightly sporradic. I looked up what they're supposed to be, and from what I could find, people say they should both be 0-60 ohms.
Now when I hook the brown/green wire that goes from the gauge to the drivers side sender straight to ground, it pins the gauge above full, and when I disconnect it, goes to below empty. Then I hook up a 1K resistor and it gives me 1/2 tank almost exactly. If a completely empty tank gives me a total 120 ish ohms resistance (according to the numbers I resarched) and completely empty off of my two measurements gives me about 210 ohms, I should get a similar result if I bypass the two senders and use about 220 ohms in resistors, which is what I did, and it BARELY moved the needle off of full.
Hope I haven't left out anything important.... but what I'm feeling like is that either the gauge is reading incorrectly, or there isn't enough resistance from one or both of the sending units when the fuel level gets low.
Anyone see some flaws in my testing or logic? Anyone know if the values I've found for the two senders are totally off?
Thanks in advance for any help!
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