Wiring newbie question

richcoleuk · May 11th, 2019, 16:56

Hi there - first non-mechanical investigation with the car, so be kind

I'm trying to diagnose a volatile fuel gauge that moves around all over the place. I've found the connections under the back seat to the fuel sensor/pump.

Would it be possible to get some help as to how to work out which wire is which and possibly how to interpret a wiring diagram (such as this - https://cardiagn.com/2007-volvo-s40-...ram-tp-3999202).

So these are the wires I have and the various voltages recorded with a multimeter:

Key position II

Blue/white - 0.06v
Red/white - 2.23v
Green/orange - 0v
Green/red - 11.8v
Orange/black - 0v

Ignition on

Blue/white - 0.06v
Red/white - 2.23v
Green/orange - 13.8v
Green/red - 14.1v
Orange/black - 0.09v

What I'm trying to check is two fold:

1. Is the resistance being sent by the sensor accurate based on the amount of fuel in the tank?
2. Can I check the fuel gauge will do a full sweep from empty to full by "pretending" to have various fuel levels by adjusting the resistance.

Hope that makes sense?

May 11th, 2019, 16:56	#1
richcoleuk New Member Last Online: Jun 8th, 2019 15:23 Join Date: Dec 2018 Location: West Sussex	Wiring newbie question Hi there - first non-mechanical investigation with the car, so be kind I'm trying to diagnose a volatile fuel gauge that moves around all over the place. I've found the connections under the back seat to the fuel sensor/pump. Would it be possible to get some help as to how to work out which wire is which and possibly how to interpret a wiring diagram (such as this - https://cardiagn.com/2007-volvo-s40-...ram-tp-3999202). So these are the wires I have and the various voltages recorded with a multimeter: Key position II Blue/white - 0.06v Red/white - 2.23v Green/orange - 0v Green/red - 11.8v Orange/black - 0v Ignition on Blue/white - 0.06v Red/white - 2.23v Green/orange - 13.8v Green/red - 14.1v Orange/black - 0.09v What I'm trying to check is two fold: 1. Is the resistance being sent by the sensor accurate based on the amount of fuel in the tank? 2. Can I check the fuel gauge will do a full sweep from empty to full by "pretending" to have various fuel levels by adjusting the resistance. Hope that makes sense? Last edited by richcoleuk; May 11th, 2019 at 17:08.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)