Hi guys... I was pulling away from a tollbooth last night and jumped on it pretty good to merge back into traffic. With the RPM's up over 4000-4500 I noticed the battery light (the red one with the + and - on it) flashing at me a few times. It only flashed while the RPMS were way up high as I was shifting out of 1st, then did it again with the RPM's up high while shifting out of 2nd. Under normal driving it never flashes at all, only when the RPM's are up near the 'redline'. Anyone heard of this? I have heard of the check engine light flashing signifying some type of an ignitition issue before such as a miss, but never heard of the battery light flashing. I've got a '98 with a 4.6 with 107k on it and have never seen the check engine light on before. I'm just about to replace the plugs/wires/coil pack (already have the parts, but have not taken the time for the install) so my ignition system is definately ready to be replaced, but I am not expierencing any kind of ignition related issues... Any ideas? Thanks in advance.....

 

Check your belt and tensioner. Could be the belt slipping under heavy load.

Rob

 

I've actually got a new Gatorback belt in the garage I need to install aswell. Had planned to do that along with the plugs, wires, coil pack, and the fuel filter here in the next week or two if it ever cools down... Why would the belt slipping cause the battery light to flash though?

 

As stated, check the tension on the belt first. If a new belt doesn't fix the issue, either the tensioner is shot or the alternator/voltage regulator is going bad.

Check the easy (cheaper) one first!

If the belt is slipping, it won't drive the alternator, and thus a fault is detected in the charging system - giving you the intermittant battery light blinking. Let me guess - your headlights dim a bit too at high rpm when the battery light is blinking?

 

I actually had the headlights off at the time, so I am not sure... I've noticed in the past when idling with my head lights on I can turn the electric windows up or down and the headlights will dim for a second I assume due to the drain on the battery. I will replace the belt if nothing else this weekend and see if that does the trick.... I appreciate the help!

 

I'd run a set of wires from the battery to the cab, and put a meter on them and repeat the prodblem.

It is a swag if the alternator is putting out too little ( belt or tensioner problem ) or too much ( voltage regulator going south ).

Put a fused connection from the pos side of the battery to the cab ( you can even run this under the wiper cowel and through an open window.

Hook up aligator clips on a volt meter, and if you have one with the hold function, set it to hold on the highest reading, and take a hammer down run to see what happens.

This tells you which way to look at the problem rather then guessing it is a too low problem, and start to do repairs, waiting for the battery light to not go on.

For 99+, there is a battery level check that can be done with the digital odometer, but you are SOL on this with a 98.

Good luck, post back what happens for the next member.

Steve