Very dim dash lights

**byoung16** · 02-24-2010, 11:42 PM

Hi,

I'm looking for some help getting the instrument panel lights to glow brighter on my 65 Riviera. The speedo and idiot light modules are a little brighter than the A/C & heater controls in the center console (which are so dim that I can barely tell the lights (4 new ones, are on). The clock light doesn't work at this time, I haven't pulled it to check yet. I've checked for all of the grounds, they are good. All other lights are good. I've added a ground wire (jumper wire) to the control box frame and the light behind the face is still just barely visible, with no improvement. I've changed the bulbs and I can see them all lighted up on the face, but very dim. When I had one of the 4 bulbs out of its socket hole in the control box, it looked like there was plenty of light coming from the opposing bulb to light up the face. It almost seems like the face is 2 thicknesses or extra darkened on the inside. But, the speedo/idiot gauge modules are too dim also, just not as dim.

One option the car does have is the automatic headlight dimmer, but I don't think it is connected to the instr. panel light circuit. I've got a genuine Buick shop manual with wiring diagrams. Like I said I confirmed all of the grounds, but there does not appear to be a ground wire specifically for the HVAC control box.

All courtesy lights are very bright. Instrument Panel fuse was replaced with a 5 amp fuse, it had a 10 amp, stock is 3 amp. I saw no change between the 10 amp & 5 amp.

Your help will be greatly appreciated,
Bill

**njlimbaugh** · 02-25-2010, 06:48 AM

The dimmer on your headlight switch may have dirty contacts, or stuck in the dim position somehow. To confirm, try jumping around the switch to see if the lights get brighter. If so, the switch is at fault. If not, the car may have acquired a lot of dirt and dust behind the light covers over the years.

**WildKitty** · 02-25-2010, 07:20 AM

the push/pull on/off headlight switch is also a reostat; a coil of wire with a contact rod that slides clockwise/counterclockwise to increase/decrease the power getting to the dash panal lights.

there could be a broken wire in the coil or the contact frozen in place.

Techtronic spray cleaner would clean dirt, corrsion from the contacts - or, if the lights are bright after you do the jump as mentioned above and that works, maybe just replace the switch.

Butch

**byoung16** · 02-25-2010, 07:29 PM

Thanks very much for the suggestions. The headlight switch reostat does turn and change the brightness, just doesn't get the job done fully. I've only owned this car for 4 months, but having been an Okla. & Colorado car, the corrosion I've found so far has been minimal. Almost like it was kept in a heated & cooled garage.

Anyway, I will be jumping the light switch to see the result.

Thanks again for your replies; very helpful.

**byoung16** · 02-28-2010, 05:40 PM

Hello again,
I bypassed the headlight switch and still have the dim HVAC control boxes in the center console. So, I tried to take the face off to clean, but the glass fronts are crimped onto the control boxes. I don't see anyway for dirt to get into the lighted area, the bulbs have dust covers.

**njlimbaugh** · 02-28-2010, 07:19 PM

Try running a wire directly from your HVAC housing to ground. I made a jumper wire that's about 15 feet long that I can connect to anything and run right to the battery. If you've got a grounding problem it will show up immediately with this method. Separate ground wires within the wiring didn't start to show up until they started using a lot of plastic in car dashboards and light housings.

**byoung16** · 03-01-2010, 06:32 PM

Thanks, I did hook up a ground wire direct like is mentioned (after I got the suggestion) and the control face letters did not light any better than before. However, now that I have the outer frame off the controls, I can clearly see that the lights are pretty bright. Their light is leaking around the outside edge of the glass front that is normally covered by the outer frame.

**byoung16** · 03-02-2010, 09:23 PM

Hello again,

I'm a member of the Riviera Owners Association and they have archived all of the issues of their newsletter. Access to the info is tricky, but I have a CD of their first 18 years of newsletters (with photos). As I was browsing the "Index", I saw the "Dim Dash Lights" heading.

To fix dim dash lights on 63-65 Rivieras replace the one candle power bulbs (#161) with two candle power (#194), this would be in the speedo & idiot light pods. Then replace the HVAC controls & clock 2cp bulbs (#1893) with 3cp bulbs (#1816). Also replace the 3 amp fuse for the "panel lights" circuit with 5 amp. I haven't done this yet, but it sounds right.

I apologize to the people that spent time trying to help me with this problem and I thank you very much for your kindness.

I forgot I had the "Riview" newsletters 18 years on CD. It was cumbersome until tonight I transferred it to a memory stick and it's like a new world.

**telriv** · 03-03-2010, 06:17 PM

The only problem going to higher candle power bulbs is that they run HOTTER! This may not be a problem if you don't do much night driving, but if you do you could start to melt the plastic that is surrounding the bulbs. One reason why some are changing over to the LED bulbs, but these also present their own problems.
Just my thoughts.

Tom T.

**byoung16** · 03-03-2010, 09:11 PM

Tom T., your thoughts about the heat are appreciated. Your point is well taken. I don't think the heat will hurt the HVAC control unit because the housing is metal and the light sockets ground to it & the lenses are glass. However, I'm not sure about the speedo & idiot light housings but the lenses are plastic. I assume the housings are metal since the light sockets also ground thru the socket hole.

I'm also calculating how much night time driving I might do.

Thanks,
byoung