Interior, headlights and rear lights flickering..

What to check ???

 

Alternator

 

I tried to reach the plug but I need to remove the alt bolts first.

How to check the alt ? Don't tell me I need a new one

 

Also check for a bad chassis ground.

 

Could also be bad ground in your instrument cluster

is it "all" your lights or just the ones in the digital dash?

 

My 93 did the same thing when I bought it and replaceing the alternator was on the list of things to do. The first project was to change the top post battery to a side post. It looked like one post was very close to a bracket and I thought it could short the car out. The battery was replaced and cables cleaned and reconnected and the problem was solved and that was two years ago. I know thats not going to work everytime but this time it was most likely a bad ground on the battery. Once in a while it's the simple fix to a problem but unfortunately not often enough .

 

Check all your grounds first. Any starter / alternator shops in your area? They can test it. I know you don't have an Autozone on every corner like we do, but if you have a place that rebuilds starters and alternators, they can test it. May be a flaky diode in the alternator.

 

All interior lights and headlights


There are many places that work with alternators , but I want to check it by myself , what's the procedure for that ?

 

Unless you have a diagnostic tester I suggest driving the car over to an equipped shop or removing the alternator to have it tested. It's prob the internal voltage regulator that's causing the issue.

 

FWIW I took my alt out 2 days ago, got it tested at Advanced Auto Parts (for free) and ended up buying a new Duralast Gold with Lifetime Warranty for $130-$10 core.

 

Not sure if the op can get that deal in Saudi Arabia

 

check your engine to frame ground strap

 

UPDATE :::

Checked the alt , engine off : 12.5 , engine running : 14.8- 15.0

I didn't find lose wire and I don't know the location of the ground wires .

I found the left knock sensor wire was cut !!!


Is there any info where can I find all the grounds ?

 

There is a steel braided ground strap that attaches to where the tranny and bell housing come together....then there is one in the back that attaches to the D36/D44.

They are flat and braided

 

"Ripple" is the term referring to voltage fluctuations on a DC circuit. If the voltage regulator is not working, there can easily be enough ripple to cause the symptoms you are describing.

Two common faults of AC ripple are a fault within the voltage regulator circuit itself, or a problem with the field connection. Grounding connections are also important, but the alternator gets it grounds from the block which is connected by a large cable connected to the negative terminal of the battery. Usually, a ground fault on that link will cause problems with the starter, etc, LONG before it will result in a charging issue. But! Never assume!



Right off the bat, the voltage is a bit out of the normal high side of the regulation window. As a rule, the voltage \is typically around 14.5-14.6 (cold engine, or low as 13.5 on a hot engine that has been running for a while). The key (again) is that ripple.

Is the voltage steady or fluctuating a few tenths? You say 14.8 to 15.0, but is that steady, or is it constantly varying between the two?

I don't have a figure for what is normal, far as ripple goes, but if you're seeing it in the dash and the headlights, it will have to be upward of a half a volt or more. (I'll get back with more info on that)

Most meters, but not all, will read fluctuations or "ripple" on a DC source. Usually, one simply selects the "AC" (~) mode when measuring the DC voltage, and some meters have a dedicated DC/AC combination function, and some digital meters also have bar graph - usually at the bottom of the screen. (The bar similates an analog measurement by displaying amplitude. It should be steady, or toggling no more than a single segment. (Note: Digital meters break an analog voltage into incremental steps. If the analog voltage is right at the threshold of one of the increments, a tiny fluctuation will cause the next higher step to toggle on and off according to "noise" on the analog voltage.))

In the mean time, check the field connection on the back of the alternator - clean it if necessary, and if negative connections on the block and both the connections on the battery are cleaned, and the problem persists, my money is on the voltage regulator in the alternator.



Obviously, the knock sensor wire should not be cut. The question I have is "why?".

As for most of the peripheral circuit grounds, the grounds are usually found on the bolts that hold the belhousing or transmission to the block. They "might" be a bitch to get to.

More later.

P.

 

I'm having the same flickering problem. Its more noticeable in the dash lights though. Alternator is the loudest part on the serpentine belt system though.

 

on the passenger side of BH, and mine was pain to replace