74 dash lights
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Either the grounding wire for the dash electricals has a problem (dirty connection; decaying wire; etc) or the main light switch is getting corroded terminals. When your headlights are on for some amount of time, feel the dash pad around the light switch. If it is getting fairly warm, that is a signal that the contacts are not "clean" and current is being dumped due to that corrosion. Problem is, the repro light switches aren't built nearly as well as the originals. If you pull your old one out, you might want to see if you can clean up the contacts and re-use it.
The ground wire is the more likely cause for weak dash lights.
The ground wire is the more likely cause for weak dash lights.
Le Mans Master
Joined: Aug 2006
Posts: 7,427
Likes: 1,560
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
That just might be normal...
There are 3 ground points, one for the speedometer, one for the tachometer and the one for the center gauges which is a black wire on the center terminal of the water temp gauge.
Those wires attach to the frame just below the headlight switch.
For a test you can jumper from the "Courtesy light fuse" to the "Instrument light fuse" and see if the lights are any brighter. If yes then the rheostat in the headlight switch has to much resistance. If the same then that's as good as it gets.
Those wires attach to the frame just below the headlight switch.
For a test you can jumper from the "Courtesy light fuse" to the "Instrument light fuse" and see if the lights are any brighter. If yes then the rheostat in the headlight switch has to much resistance. If the same then that's as good as it gets.
Last edited by Peterbuilt; Aug 13, 2013 at 03:35 PM.
Instructor
Joined: May 2013
Posts: 143
Likes: 0
From: Carrollton TX
If you sort out all the wiring and it isn't bright enough for you you can switch them to LED bulbs, it is the same installation process as putting in the conventional bulbs - but you will lose the ability to use the dimmer.
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Burning Brakes
Joined: Apr 2012
Posts: 1,084
Likes: 96
From: Bowmanville Ontario
Oh MAN,
I am in the process of switching over to LED's and this is the biggest PITA job I have ever done. so far.
Who ever's idea was it to wrap that massive wire harness over the top of the guages was a MORON.
I have dropped 6 bulbs inside so far, last night I gave up at 10:00 after reinstalling the guages for the 6th time. I will try again tonight to get the bulbs in.
The only way to install these bulbs is to do it from the floor looking up.
I tried to replace the indicator bulbs with LED's but they don't work correctly, so I pulled them back out and put in the regular bulbs for now. I think there is some relay that has to be changed as someone on the forum posted.
On a lighter note...the dash is starting to look amazing with the LED's in. Nice and bright and clear.
I am in the process of switching over to LED's and this is the biggest PITA job I have ever done. so far.
Who ever's idea was it to wrap that massive wire harness over the top of the guages was a MORON.
I have dropped 6 bulbs inside so far, last night I gave up at 10:00 after reinstalling the guages for the 6th time. I will try again tonight to get the bulbs in.
The only way to install these bulbs is to do it from the floor looking up.
I tried to replace the indicator bulbs with LED's but they don't work correctly, so I pulled them back out and put in the regular bulbs for now. I think there is some relay that has to be changed as someone on the forum posted.
On a lighter note...the dash is starting to look amazing with the LED's in. Nice and bright and clear.
Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
DC
