I just got a 5in Tach for my Firebird and I'm trying to get it wired but I have to connect it to the dimmer switch but I don't know what wire that is and I can't get the hush panel under the dash off. Any help or ideas?

 

Are you trying to achieve the tachs light to turn on with the headlights? If so, tap into the "Hot" wire for the light bulb in the HVAC unit. Thats what I did. Use a T-Tap to make a clean connection.

 

Pueblo huh. I was stationed at Ft. Carson back in 2000-2004. Good times.

 

I will see if I can figure out which one is the hot wire tomorrow. Yeah that's just a 30min drive away. I was just up at that base not to long ago visiting some friends.

 

That's easy. If you have a voltmeter, just turn on the headlights and remove the hvac bulb. Then probe the metal tabs inside the connector. Piece of cake.

 

Yeah that doesn't sound to bad. See I can wire up speakers but I've never done tachs so it's all new to me haha. I have another quick question. Where did you hook up the power? I know some people hook it up in the fuse box but in what slot?

 

If you can't access under the hush panel, you can also tap into the "hot" power lead of the stereo. It's a lot easier because you can easily access that wire and not have to make the tach wire longer.

 

Alright so I couldn't get my hands in behind the hvac to find the wire but I was able to get the hush panel off can you remember what wires to hook the (red) power wire up to, (white) the dimmer wire up to, and (green) the tachometer wire up to?

 

The stock white tacho signal wire goes to the plug on the back of gauges
Google for a pinout of the wire configuration on the plug

 

I have everything else hooked up and I can set the shift light and everything and I hooked it up to the only white wire hooked up to the back of the gauges but nothing. I tried looking on google but nothing

 

So the white wire is tapped into the white wire and your not getting an rpm reading?

 

The green wire is tapped into the white wire and I'm not getting a reading but I did run across this and it says it's on the passenger side? http://www.austinthirdgen.org/mkport...ter_pinout.jpg

 

http://forums.chevyhiperformance.com...h-not-working/

There is a wiring diagram here for you to follow.

 

In my 86 IROC, all the wires needed was just there. I ran a positive wire and tapped into the main power lead of the stereo. The illumination I tapped into the 194 lightbuld wire just behind the hvac unit faceplate. Ground was tapped into the stereos ground. The green wire was tapped into the white wire under the driver side dash.

 

That may be it. I don't know. Between 86 and 92, the wiring changed. But it's worth a shot.

 

Well right after I posted that comment I went back out to my car and was looking at it and the wire is a smaller gauge and so the connector I used didn't break through to touch the wires so that's why it wasn't working but I got everything working now at 1:00a.m. haha Thank you for helping me out!

 

Everything works great

 

Good job man!!! Glad it all worked out. Sometimes it's the small things that we all overlook. Also, you have one cool look tach man. I'd use more explicit words to express how cool the tach looks, but these threads are "Rated G". Hahaha