Question] Dashboard light dimmed and not stable...

Undefined

Junior Member
Messages
78
Hi,

Noticed some problem with my 3200 in these few days, appreciate anybody could give out his view on what I should look at.

In recent days, I noticed that after a few minutes started and then turn on the light, the light on the dashboard sometimes got dimmed and not stable, but after the car ran for a few moment, the light is ok; and I didn't turned on the a/c.

Then, I used my car again today, after I started the car and then, turned on the light and a/c (since it's raining), I noticed that the light on the dashboard got dimmed sometimes, even not just after the few minutes the engine started. When I was driving on a highway, I could see the dashboard light dimmed like it didn't have turned on for over 10 seconds. I noticed that there is a very minor movement in the voltage meter (the movement was so small that I really need to look into it very carefully to observe it moved), and not even at the level that trigger the warning light.

While the dashboard light dimmed, it seemed not affecting the headlight or other electronics; and so far seems like other things go fine. Fingercrossed!

Is that something about the alternator or the rectifier? Or any relay should I look into the problem?

I will try taking the video of how the the dashboard light dimmed; but I will be out of town for a few days, so, may post a bit later.

Appreciate for your help and advice! Thank you very much!

Best regards,
Michael.
 

CatmanV2

Member
Messages
48,543
Check your battery connections and the condition of your battery would be my start.

Might be the alternator / regulator as well, or some other bits, but simple stuff first :)

C
 

LORENZ-GS

Junior Member
Messages
412
Im thinking that its not a battery or alternator issue. If it was the headlights would be dimming to...however whenever theres an electrical issue its always nice to double check the charging system so i would check it
 

CatmanV2

Member
Messages
48,543
Im thinking that its not a battery or alternator issue. If it was the headlights would be dimming to...however whenever theres an electrical issue its always nice to double check the charging system so i would check it

Yep, I hear you. Xenons won't dim though. Might be just enough to keep the arc sustained.

Ahhh, did the 3200 ever come with Xenons?

C
 

LORENZ-GS

Junior Member
Messages
412
Zenons not dimming may be a possibility. If thats the case, when this dimming occurs in the dash lights, check the door lights , interior dome lights or even the rear lights to see if they dim to. Maybe that will give some indication of things. But id still put a volt meter at the battery to check the alternator
 

Undefined

Junior Member
Messages
78
Thanks all!

My car has Xenon headlight... although I was told by my mechanic that it is an aftermarket one... so, if Xenon light won't dim due to the voltage fluctuation, it may not be a good indication.

I had a brief check on the battery connector, they should be tight.... well.... maybe a good idea to disconnect them, cleaning them and reconnect it when I get back a few days later.... will see how the door and interior lights dimmed together as well....
 

davy83

Member
Messages
2,809
What exactly is dimming? its not clear from your message? If the instrument illumination is the problem have you tried wiggling the black brightness control on the instrument binnacle? It is prone to being a bit flakey and if you twist it around a bit it may just recover. If its warning lights then which ones?
 

Undefined

Junior Member
Messages
78
What exactly is dimming? its not clear from your message? If the instrument illumination is the problem have you tried wiggling the black brightness control on the instrument binnacle? It is prone to being a bit flakey and if you twist it around a bit it may just recover. If its warning lights then which ones?

Just return from my trip....

It is the instrument illumination, no warning light pops up so far.... Let me check it out when I have to getting to the car.... Thanks!
 

Undefined

Junior Member
Messages
78
Managed to do some test on the car... well... noticed that the room light will dim together when the dashboard light dims. Used multitester to check the voltage at the battery connector while the engine was running, noticed that sometimes the voltage was not so stable... most of the time was above 14v and sometimes it dropped to 13v and the lowest one I got was 12.99v and the lights dimmed when the voltage dropped....

Tried to disconnect the battery, but the connector seems clean and tight.... Seems like for now, it is something that I may need to go asking the indy to help...
 

CatmanV2

Member
Messages
48,543
Yes. That sounds more like something's putting a sudden drain on the battery, but 12.99 I would think would be OK.

To the Indy

C
 

Undefined

Junior Member
Messages
78
Sent the car to the indy to check. He also suspected that is the alternator or the regulator inside the alternator caused problem. He had experience with a Ferrari had the similar problem and solved by just changing the regulator, not the whole alternator, by a specialist in car alternator.

However, he called me today and said that the specialist told him that he checked my alternator and doesn't found any problem with it. Of course, my indy told me that the specialist may not have all the tools to test the alternator with simulation of different loading... So, my indy said that he will check the other items for me again, including the connections to the battery, battery itself (had been checked before), testing the voltage directly from the alternator, etc.... He also advise me, if I can get another alternator to test, that could help to confirm whether it is the alternator's problem... Well... to be honest, for now, I tend to believe that is not the alternator's problem since it had been tested and my indy told me that the alternator looks pretty clean and new.... Really dunno what else I can check....

Please find a video that I took for my car's problem.. I just used my car (the car was hot) and parked at my car park without switching off while I was taking the video and I didn't touch any button or switch at that moment... but you can see the lights going on and dim and even off....

http://youtu.be/N_CXR2HWG3Q

Had anyone experience this before?

Thanks!
 

Contigo

Sponsor
Messages
18,376
If this was an alternator issue wouldn't the battery voltage meter on the dash also show a fluctuation in the output too? I see yours is stable and doesn't move at all during the flickering. Also what about the AirCon centre console backlights? Do they flicker too? I would look more at the actual Binnacle as having an intermittent problem . You could disconnect the binnacle, clean all connections with contact cleaner including the plug and retest.

The alternator's on these cars are Nippon Denso units and are usually pretty much bullet proof.

Check the battery connections too around the positive terminal, the voltage should be between 13.7V and 14.7V with the engine running so also check this.
 

Undefined

Junior Member
Messages
78
Thank you very much! Well.. I noted that the interior lights (including the Air Con console backlights, and the light at the boot, I noticed the bright and dim of the light at the boot while I was measuring the voltage at the battery....) go bright and dim at the same time as the dashboard lights... I am asking my mechanic to have a check on the connection... well... hope that they can find that out....
 

highlander

Member
Messages
5,214
not experienced anything like it before but looks like a short to me.........but would have expected your indy to find that if that was the case:unsure:
 

Undefined

Junior Member
Messages
78
My indy told me that, he believes that sudden drop in the voltage that he and I measured was because of the start of the A/C fan, and the drop of the voltage doesn't not drop down too far and would be get back to normal immediately, so, he believes that is not the reason causing the light dimmed.

However, bad news, he told me that he turned the knob on the dashboard that supposed to adjust the brightness of the light on the dashboard, and he said the it doesn't work and, now, eventually, most of the time goes out..... So, probably he said that I have to change the rheostat on the dashboard! He also said that from his experience, the room light doesn't go off together with the dashboard light... could be just at that moment, I have some fluctuation in the voltage during the engine was warming up and caused the issue.

Oh! Goosh! I don't really mind paying for the rheostat, but, the problem is, I have to wait for the parts (even the local dealer said that it needs 3 weeks for the parts to arrive) and for the time being, I may not be able to see the dashboard while driving at nite...

I though of asking my indy to just short the circuit since, in fact, before he told me today, I don't even know that knob was to turn the brightness of the dashboard light! LOL. However this still got some efforts in taking off the dash, which could be quite a tough job... in this case, may still be better ordering the parts and change the parts...

In fact, are there any substitution for this parts?

Thank you very much!
 

Undefined

Junior Member
Messages
78
Miracle happened!

While I was waiting my indy to order the rheostat from the local dealer ('cos the cost is almost the same if I am going to order from Eurospares after adding the shipping cost), I used my car with the dashboard light off all the time... A few days before, I sent my car to my indy again since my coolant hose to the turbo failed... that was an easy fix.

When I picked up my car from my indy, he said that while he test-drove, he turned on the light (since it was dark), and the dashboard light come alive again.... and the rheostat was working normally to turn the light dim and bright.... So, for now, probably is no longer the problem with the rheostat... my indy suspect that was the switch that turn the light on/off... but, to be honest, I doubt it, since if that was the switch, the headlight should be affected as well....

Just wonder whether there are any thing that would affect the light of the dashboard? Would there be any relay in between? Thank you very much!
 

Grinzzz

New Member
Messages
925
If it's a true rheostat as opposed to a potentiometer then what might have happened is that the coils of wire get a surface corrosion on them. Moving the control back and forth can clear the corrosion as the arm/blade wipe the coils. Unlikely but perfectly possible. Use it more often!