Dash Lights??

They're not ever very bright even if everything is in perfect condition. Obviously there is no valid reason for a dimmer switch with such weak bulbs so it is best to pull out the switch, remove the wires going to it, connect the two wires together in a good manner (solder etc.), insulate the connection and re-install everything. If you see any improvement in brightness you will also know that the dimmer switch was a contributing factor.

There are also some threads about installing slightly brighter bulbs in the instrument panel. Easier to try the dimmer bypass first and see how things are then.

 

There are three things you can do about this:

1. Replace the bulbs (as eulk328 said)
2. Disconnect the rheostat and jump the two wires together (as eulk328 said)
3. Install new fuse blocks

You'll then have dash lights that do a decent job. There are several threads on this, and it's all pretty easy to do.

 

I've done all three, and have seen a 'slight' improvement - the Tach is still dark, however. You're dealing with a circuit that does not have a lot of voltage or current dedicated to it, so you'll have to live with what you get after you replace the bulbs and bypass the rheostat.

 

I'm not sure if the dash lamps are the same for 328's but I changed mine to these brighter lamps on my 308qv and did not even have to bypass the dimmer to get decent brightness. I do have the Birdman style fuseblocks though.
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Tom has a 328 so the fuse block/relay panel should not be an issue (improved over the 308). By chance I had mine completely apart today to look inside. It is quite well made. No signs of overheating or corrosion on any terminal. While I had it apart I applied copper based grease to all terminals. Before that it was really hard to pull out any of the fuses, relays or plugs. The electrical contacts are very tight/strong (a good thing).
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I have an 83 QV
I replaced the bulbs
I jumped the rheostat
I have birdman's fuse blocks.

Did not make a significant improvement.


What DID make an improvement is cleaning the contact switch blades & receptors thoroughly in the wiring harness.
I can once again easily see my Speedo & the rest of the gauges at night.

BTW: Some of the placement for the bulbs in the gauges just plain stinks. Take them apart & you'll see.

 

you can change them all with LED very bright low W no burden for the wires but the dimmer wont work. most new cars have LED lights so you can get them anywhere.

 

It really depends on the application. LEDs are much more directional in their light output. May not work well at all with instrument lighting. Also, the are by no means always bright or brighter than a standard bulb. The dimmer will still work but in a much more limited range.

 

Here's the whole procedure if you'd like to try it out. I swapped the bulbs but the tach is still dark. I may bybass the dimmer next time I'm in there.

http://www.nwrfca.org/faq/dashlights.html

 

Hi please when you'll bypass the dimmer do some pics so I can understand how you do and where are the wires.
Many thanks.