eaglevision993

Hi there,
I am hunting a little electrical problem here and need some input:

Recently my digital dash is slightly flickering/pulsating which is mostly visible at night. Just a slight dimmer/brighter pulsating.

This occurs only with the engine on! I already checked the connectors and installed a new alternator and battery with no change.

I donīt think it is ground related because it is only visible with the engine running.


Any ideas?
Thanks in advance

dukeallen

I'd check the plugs and wires for any shorting too. But I bet you get lucky and have to pull the dash

mazdaverx7

often times you can pull the cluster and repair the unit by resoldering faulty solder joints or a faulty ground. sometimes its more extensive and you will need to send your cluster in for a rebuild. all too common my friend.

uptown193

Maybe your bulbs are about to go out.

mazdaverx7

its an LCD dash, no bulbs

C422

The LCD's backlight is a bulb. And all the other lights are bulbs. There's no such thing as a light emitting LCD.

eaglevision993

Yes it is bulb illuminated....The bulbs are the ones that flicker, not the LCD display element.

mazdaverx7

you guys are totally correction that. for some reason i was thinking you were referring to it as being a standard type dash. my fault totally.

eaglevision993

OK, UPDATE:

I removed the digital cluster, disassembled, cleaned, and resoldered every suspicious place.
Still the same. So I did a few more tests.

I recently replaced my alternator because of the flickering, battery is also new so I ruled that out.
But I noticed that the flickering only occurs with the engine on. With the engine off, the dimmer and everything works just as it should.

So I did the following. I attached jumpstart cables on the Vette and my other car (Cadillac Seville STS). Started the Cadillac and only had the Vetteīs ignition on, not the engine. So I simulated a running/loading alternator state. With this setup the problem is still not there so I am leaning towards the new alternator being faulty....

Any thought before digging in the alternator once more?

uptown193

Ok, so did you change any of the blubs in the cluster as I previously mentioned in my post from yesterday? I am not saying this is the problem but it may have something to do with it.

eaglevision993

Hi,
no I did not change the bulbs as I did so last year when one was bad.
But as they flicker all at the same time, I think they are fine.

Iīll have to investigate the alternator though even if it is new...

tbirdsps

I can't wait to find out the answer. My 90 does the same but it does it at a pretty slow and intermittent rate. It seems to only do it when the headlights or driving lights are on. I certainly would not have suspected the alternator. Mine only does it when driving so I suspected a loose ground or other connection. I've never noticed it when driving with no lights during the day time.

Willymo

I had the exact same problem as you did. The car would either be at idle or driving and every light in my car would flicker. I looked into the grounds and battery as well and didn't find anything wrong. A few days later I was driving home and the fan on my alternator blew apart while I was driving about 45mph and it almost punched a hole through my hood. When I replaced the alternator, the flickering disappeared and I haven't had a problem since.

eaglevision993

Thanks for the input. When I have some time in the next couple of days I will check the alternator.
Best regards

Midnight 85

See if the parking lights also do it, if they flicker just like the dash it is most likely a bad regulator in the alternator, even a new alternator.

sk1faninpa

some times the dash lights will be on,and when it's real hot they are out with the turn signal lights on. then you can be driving and they come on, was thinking of replacing or send it in for repairs. has anybody have the same problems with there dash lights?

eaglevision993

That sounds like a ground problem, maybe due to a cold solder joint....Look on bateeīs website for ground problems.

As for me, the interior and exterior lights donīt seem so flicker as significantly as the dash does. But I still think the problem is to be found in the alternator direction....Iīll check that out soon.

Cliff Harris

The alternator output can be really low at idle. You can see this on the voltmeter display. It is actually an AC (alternating current) output that get changed to DC (direct current) by the diodes in the alternator. It is still pulsing slightly, which is partially filtered out by the battery.

Try increasing the RPM slightly with the gas pedal (in neutral -- 1500 RPM should be enough to get you up into the upper 13 volt area) and see if the flickering goes away.

I find that my dash flickers at idle when a turn signal is on.

eaglevision993

ok, UPDATE and SOLUTION!!!!

Finally after some days I found the time to dig into the matter: I rechecked the battery and alternator again to no avail...

Then I disassembled the digital dash, cleaned it, resoldered everything, added the additional ground wire per batee.comīs instructions and.....nothing....same.

Today I did not plan to work on, just wanted to get something to eat and as I tried to start the engine: totally dead. Everything came on as I put the ignition on but as I went to start the engine every electric device just quit.

No lights, no crank, no dash...

I disconnected the battery and reconnection solves the problem for 2 more cranks then again totally dead while trying to start.


Long story short, I kept a closer look at the battery cables and the negative clamp was the problem. Not the screw that holds it to the battery but the part where the thick cable goes into the clamp itself. The screws were lose!

So the car had an intermittend ground and that is what caused all the problems above!

No more flickering, starts fine, stable voltage.
Problem solved, at least I hope so...

Thanks for all your help and input. At least I now know how the digital dash looks and works inside....

Best regards
Benjamin

Willymo

Great news