98 Cobra - lights flicker/pulse

[subsGT]

hey everyone...

before I start beating myself up on this, would like a few opinions. I have this car, built 4V, D1SC, 6sp etc...I keep it parked inside and only drive on nice days. I went out 2 days ago to take it out and the battery was dead. It's a new Motocraft, less then a year, and needed a full charge to start it. Put in a red top just to see and the same thing happened. When the car is running, the dome, instrument and headlights all pulse, sometimes a little, sometimes a lot...
Could this be a bad ground? Alternator?? Is it related?

 

[COBRA90GT]

Sounds like it's time to start chasing an electrical gremlin - checking grounds on circuits that have been "altered" isn't a bad idea. You'll have to pinpoint which circuit(s) is draining your battery.

Is it completely drained while it sits for just one night or does it take a few days of sitting for it to drain ?


If don't want to do all that work right now, hooking up an inexpensive battery float charger
(ie - Battery Tender or similar) while the car sits in the garage probably wouldn't be a bad idea.

 

[subsGT]

it'll hold a charge for a few days...I just hate car electrical problems...eckk!
Might pick up a trickle charger anyway...

 

[wmburns]

Just wondering if the battery and alternator have been TESTED? Take it to your local autoparts store and have the alternator tested for correct output and excessive AC ripple. This may be as simple as a bad alternator diode or voltage regulator.

Normally I would recommed having the battery tested. But since it is new, it should be OK. However, are the battery terminals CLEAN, corrosion free, and tight?

As suggested as well, not a bad idea to confirm the grounds. Esp the ones around the battery. Confirm that the engine grounding strap from the left hand motor mounts to the frame rail is in place.

When the problem occurs, what does the battery voltage do (volt range)?

 

[subsGT]

My next step will be to take it to my friend mechanic and put a tester on it, but the battery charger I use indicates the charging system is working properly when running...