Battery light flickering on and off

HGSJAKE

MEMBER
2005 MERCURY MARINER
4 CYL
4WD
AUTOMATIC
140,000 MILES

Hello,

I have had a problem with my battery light turning on and off over the last month.

I have replaced my battery, my alternator, the serpentine belt, the belt tension-er, and now a mechanic is telling me that I need to have the fuel system cleaned and my spark plugs and wires replaced, otherwise the problem will not go away.

I am not a professional, but my father-in-law and I cannot seem to figure out why the spark plugs would not be a check engine problem. I have used Seafoam fuel system cleaner, and I will be using it again today, but it just does not make sense to me that the fuel system and spark plugs would trigger the battery light. I am worried that fixing those things will not fix the problem. Is there anything else that could be causing that problem? Thank you.

1 Reply

MHPAUTOS

MECHANIC
31,938 POSTS

The ignition system will not be at fault, you need to get the alternator out put checked you want around 14.5 V and make sure all main earth terminals are clean and tight, as it the alternator main feed wire, also look for any burning on that wire at the alternator, check all battery terminals are clean and tight, the problem is something to do with the charging system, if in doubt about your mechanics ability to do this, go find another mechanic.