Fluctuating Fuel Guage

[xwarlord]

Recently replaced horn airbag frame and subsequently the fuel indicator occassionally goes to empty with warning light activated. Thus far it has returned to normal operation but continues sporadically. Any suggestions?

[Loren]

As your topic appears to be a DIY question (rather than a DIY Tutorial), we have moved it to the appropriate forum.

This is an automatically generated reply.

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[JFP in PA]

Recently replaced horn airbag frame and subsequently the fuel indicator occassionally goes to empty with warning light activated. Thus far it has returned to normal operation but continues sporadically. Any suggestions?

Several possibilities; is anything else acting up? Reason I ask is it could be a wiring issue (often rodent related damage), a bad sensor in the tank, a weak battery, or a bad ignition switch……….

[xwarlord]

Everything else is normal, no damage, only started following frame replacement. Wondering if it could be related to removing negative battery cable as post replacement was first occurance.

[JFP in PA]

OK, let's start with the basics, this is a 986 Boxster, correct? Which year?

Please explain your "frame replacement" comment. Thanks.

[xwarlord]

98, 986,correct

[xwarlord]

I replaced the horn bag airframe to fix a stuck horn. After completion of replacement and reconnection of electrical power, the fluctuating began

[JFP in PA]

I replaced the horn bag airframe to fix a stuck horn. After completion of replacement and reconnection of electrical power, the fluctuating began

I doubt they are related, but there is always that chance.

Usually, when the fuel gauge starts fluctuating, with the low fuel light coming on, it is either a wiring issue with the fuel sender unit, or the sender unit itself. The sender can be tested with a multimeter, but the procedure is a bit messy asaccess to it is under the car's battery tray, so it becomes difficult to set this up as a "road test". As I mentioned earlier, this seems to be a favorite spot for rodent damage (chewed wiring).

One thing you may want to try before check the fuel wiring is to wiggle the ignition key when the fault appears, sometimes these issues are related to the start of a failing ignition switch.

[xwarlord]

JFP, Thank you for the info/diagnosis. Will check out the problem with this guidance.