Hello folks...
First post to the forum from which I have already learned soo much and helped to make a decision to buy an Excursion to replace my suburban instead of going back to another sub.

Bought a 2001 Excursion Limited, V8 5.4L Triton 4x4 with 135k miles and love it!!! Already put about 15oo miles on it since Xmas and now time to address some issues.

Primary is that I noticed that interior, dash and exterior lights tend to flicker when @ idle, but nothing else so no worries. Well, yesterday, get in the Ex go go home and it doesn't start. Cranks just enough to click - sure si GN battery is dead. Jump start it and drive it to AZ where they check the batt and alt, both which read fine. I buy a new battery just in case the one in the Ex is shot since it was installed in 2009. Drove home no worries. Try to start the Ex today to go to work, and nothing but constant clicking and battery is dead. Replace with new battery and starts on first crank - lights flicker @ idle intermettently. Go to local mechanic shop - tests the alt and says it's good as output even under load is 14v as @ idle. I go to work which is about 2 miles away and as I am backin in the Ex into parking spot, idle drops to almost stalling and lights dim (but no battery light on the dash). I put in park and all is well, just a min amount of light flickering. As a precaution, I get the alt replaced so I know that now I have a new battery and new alt in the Ex...alas, the light flickering is still there @ idle. Gets worse when I turn on the rear defrost @ idle, but is ok when under load/driving.

Ay thoughts as to what could be wrong or what to look into next? The grey fusible links to the left of the battery on the pass fender firewall? What is the "mega fuse" and where might it be located in my V8 5.4L engine bay? We are on the road with kids a lot and I don't like having electrical gremlins in the car, especially when wife drives it with kids, so any assistance would be greatly appreciated.

Thanks in advance!

 

Welcome tirefryer.

Check to make sure all your chassis grounds are clean and tight. Do the same with all your battery terminals, and alternator charge wire connections. Make sure the alternator charge wire is in good condition, along with the smaller wires connected to the alternator. If you're sure they are all good, start working your way towards the main fuse panel, checking all the connections between.

 

Thanks, William_04_x

Would any of the items you stated lead to a drain in the electrical system enough to drain the battery overnight? What's a good way to check for drain? Its been cold (low to mid 20s) for past week, but hasn't been an issue to crank/start the Ex till yesterday. It's been parked since 6pm tonight and will see how it starts up in an hour when I go to pick up sister from airport.

I will make time this weekend to check all them items you mentioned and report back.

 

I think you have a charging problem, not necessarily a drain. I bet something is loose, or corroded. Do you know if the "excite" wire to your alternator is commanding a charge? What is the voltage at the battery with the engine at idle, and at 2K RPM's?

You can throw an amp clamp on your battery to see if you have something drawing power when the truck is off. Anything more than 150ma or so and it's time to start pulling fuses to isolate the problem circuit.

A voltmeter can really tell you a lot. With the truck idling, you should see charge voltage(13.5+) at the battery, with no accessories on. You can then start turning things on one at a time to see if any particular circuit causes a drastic change. Check your voltage while cranking the engine.

 

@ idle and 2k rpm, voltage @ battery were 14.39v and 14.41v respectively, with new batt and old alt - this was done at advanced auto.

I will check connections, grounds and integrity of the wires this weekend.

 

Wonder if you may have a bad dome light switch in the door latches causing the flickering? Then, overnight, the dome light is on all night and drain your battery?

Does the door light come on when the lights flicker?

If so, spray some WD-40 in the door latches to clean it.

 

Niet. No door lights when light flickers, but I will WD40 the latches as a precaution

On a side note, started the car after letting sit for 4hrs @ 22F temp, and it started right up on first crank.... Let's see how tomorrow morning does.

 

I think that the replacement alternator is bad as well.

I had my battery light flicker once only at hwy speed. It was ok on the volt meter at idle. Got a good rebuilt alternator/voltage regulator and problem went away.

 

I have yet to see the battery light come on or flicker on the dash. I am going to test the alt I removed from the Ex and see what I find. Will probably get that rebuilt locally properly and swap it back if the connections don't solve the issues.

Btw, any insight into the fusible links/mega fuse or is that of no consequence?

Thanks!