Hi

I have been very happy driving my jeep during the last few days of vacation
For the first time I drove at night.

I discovered that along with a very slightly up and down idle, the lights in and out of the car are fluctuating.
not very obvious on the video.

seems to disappear when accelerating.

any advice ?


(I appplied Cruiser’ tips in the engine bay)


thanks

 

You cleaned ALL the grounds?

Are you sure?

How fast is your engine idling?

What's your alternator output voltage at idle?

 

I cleaned all of them in the engine bay and added some where recommended.

I will do the tip for the dashboard as well. But headlights are also affected. So I guess the problem is somewhere else.

IDLE : I have no clue but I think it is low. The RPM shown is inaccurate, I know it. « Needles » have been adjusted by hand several time. How can I know ?

Where can I check the different voltage to identify who is liable ? On the alternator ?

 

Just check with a meter at the battery, both with the engine off and at idle. Let us know the results of each, please.

You need to get an accurate RPM measurement. Perhaps you can rent a tachometer?

 

Sounds like bad connections BAtt to Alt, or grounds, possibly bad Alternator. Voltage should be steady because the battery is like a connected load to a charging alternator. Voltage should be steady, it obviously isn't. Clean the connections and tighten them up and have the alternator checked.

 

Here are the data
car was parked for one full day and a half.
measurements directly on the battery.

- engine off (cold weather) : 12.65v
- engine off + lights on : 11.88v
- engine on (cold, idling probably a bit low) : 15.18 to 15.21 (fluctuating a bit)
- engine on (same conditions) + lights on : about 15.20

after 5 minutes, I Remembered to get additional results withe the engine is revving.

- engine off was now : 12.19v
- engine on : 15.13v, increasing slowly (fluctuating)
- revving the engine : measurement lowering towards 15v when revved really hard. (The faster, the closer to 15.0v)


hope it can help diagnose the issue.
and maybe solve some others

 

As stated before, have the charging system and alternator checked at a big box store like Autozone.
**After thought, it could be your only problem is a bad battery. Regulator is charging at max to compensate

 

Hi,

I know it would be better to go to a dealer and get the alternator checked.
But is isn't like that down here in europe. At least where I live.

What I can do is book a meeting. I'll have to leave the car for a few days so a mecanic (a trainee?) will look at it.
I'll be charged 100$ and be told that the car is old, no parts are available (...).
At best they will tell me the cost would be 1000$ so that I don't disturb them anymore.

I did read that over 15v is NOT normal, but yes, maybe the alternator tries to compensate a somewhat weak battery.
Or it overcharges and this is why the battery is dead.

Any other way to know ?
- I added grounds (according to Cuiser's guide) is it possible that I did something wrong causing these values (over 15V) ?
- There is a circuit breaker on the ground coming from the battery. It is new and looks goods, can it be a source of issue ?

 

Thanks Grand4.0

I moved the discussion on the battery / alternator / regulator to another thread.
To make answers easily findable for the other members.

I'll continue here if solving these doesn't solve the dashboard ligths issue.
(I will refresh the grounds of the dashboard soon)

 

Here in the good old USA USA USA we can just drive to a parts store, and for free, they put a computer tester on the car and check battery condition, as well as alternator diodes, regulator etc.
I suspect a bad battery and maybe alternator. Do you have a volt ohm meter? As stated, you could watch the voltage at the battery while running the engine and see if it fluctuates with the flickering dash lights.

 

"Here in the good old USA" ...

 

Comment allez vous, and stuff.

 

 

.

 

Outstanding! I see the image from my email but it has trouble loading on the thread, ..great pic is that a real army jeep? Nice boys too..Tres Bien!