Tried searching and didn't really find anything online. Fuses look decent. Traced most of the wiring but wondering if this is a common issue..

At night, turn headlights on and sometimes the dash lights and brake lights cut out completely. It seems as if SOMETIMES I can fix it by jiggling the headlight switch on the steering wheel. Also, at times the headlights will start randomly popping up and down. I jumped the security relay under the dash. Not sure if this could be a security issue. Any help or ideas will be appreciated. I'm wondering if a relay is going bad..

 

CPU #2 (the box in the driver footwell, which controls the alarm system, among other things) has been known to go a little funky when the battery is on its last legs. I would have the battery tested. Or you could simply attach a voltmeter to it.

 

Hmmm.. Well I just started the car up for the first time in seven years AFTER a huge overhaul. Battery is a yellow top Optima and I always check Bar Voltage with the Power FC commander and my laptop/datalogit. Battery has been around 13.9 V for a while now. The battery was weak 2 months ago because it was most likely on a shelf somewhere and then most of my initial tuning was in the driveway for only a few min at a time. Now that I drive her everyday, with an IRP 140 amp alternator, she seems to be fine.

I wonder how often CPU #2 goes bad...

 

13.9V from the battery seems high, particularly if it has been sitting for years. Is that with the engine off? With the engine on you are measuring alternator voltage.

 

No, I purchased the battery within a year. That's with the engine on, alternator output, correct. With it off, it is in the high 11.x V to 12V

 

I have KINDA narrowed it down. Other forums say that it could be the TNS relay by the hood latch or it could be the headlight switch on the steering column. Hopefully not ECU 2... Which is $260.

 

I have some good CPU #2 units so send me a PM if you need one.

 

get the grounds on the front behind the bumper, beside the horns. There are two tabs which are central grounding points. If these are "shady" the lights will go dim, and they will flicker up and down.

 

Check your main car harness in the drives side fender well on the front side.

thewird