Originally Posted by
throttle jockey
Mechanical or electric vaccum/boost gauge? If it a mechanical gauge then the gauge's abilty to display vaccum/boost does not need any electrical source to operate and it also has nothing to do with the electrical source needed to illuminate the gauge.
With electric gauges you need a switched source to power the gauge for operation and a separate power source for the gauge lightning. The lightning should be tied into the dash light dimmer switch so the aftermarket gauge illumination can be dimmed with the factory gauge cluster. Pull the headlight switch housing out of the dash and use a test light to find the dimmer switch to identify the correct wire. Since you're using and add-a-fuse you should be able to draw power from the dash light fuse but I am not certain if this will allow you to dim the aftermarket gauge(s).
It's a mechanical gauge but as stated in my OP the problem isn't with the vacuum portion of the gauge (that's working just fine), it simply won't light. I previously had an AutoMeter gauge installed and loved it however it needs to be re-calibrated and I was looking for a change so I got something new. I had the AutoMeter installed exactly as you described however this new gauge requires a 12v constant (un-switched) source as well as a 12v switched source so unfortunately the dimmer wire won't work. Nevertheless I appreciate the reply. Hopefully I'll hear back from the manufacturer tomorrow as I'm really starting to think I may have just received a bad gauge. I just figured in the meantime I'd post up here in case there was something that I had done wrong or was missing that was blatantly obvious to others and I was just missing
'02 Dark Shadow Grey - #2679
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