Trans Temp Gauge light on dimmer

Installed an AutoMeter Trans Temp in my 97 3.4 4WD auto. Trying to connect the back light to the dimmer, so it can dim with my dash lights. Tapped the + lead of the socket on the gauge to the lead that I found that dims from the dimmer switch, but the bulb on the temp gauge dims opposite of the instrument cluster, meaning when the instrument cluster is at full brightness the temp gauge bulb is at it's dimmest and vice versa. Also, when the temp gauge is at full brightness, it is hardly visible at night.

Any suggestions?

 

Sounds like the polarity is reversed . Strange on a 12 volt set up mind you

 

That's what I am thinking. Was thinking of switching it to see if that's the case, next chance I get.

 

Off topic but where did you place the temp prob and what temp reading are you seeing fully warm and driving?

thanks and yeah try reversing the polarity and have a good clean ground.

 

I haven't connected the gauge to the sender, yet. Need to go to the Tranny shop and he will bead the sender into the pan for me. Hoping will be doing it next weekend.

 

Got the sender installed and gauge working on Saturday. My tranny guy put the sender on the trans pan on the passenger side on the side of the pan. Will post a pic of the sender when I can. Today, was the most I have driven since getting the gauge all hooked up and the temp was at about 205*.

 

I am doing something similar and have the same problem? Was the resolve by reversing the polarity of the bulb? Thanks in advance if anyone can help me with the same/similar problem.

Happy Wheel'n

 

https://www.tacomaworld.com/threads...rtmr-5-relay-no-blue-sea-spod.336590/page-105
Here is a lil info on your illumination being backwards. Gotta sift through some of it, but...

Long story short, ya gotta use the W-G wire as your ground and the G-R as your positive. Then you wont have the opposite dimming effect. There should be two wires off the dimmer switch, some models have three i think but itll be the same solution reguardless. Use the W-G off the dimmer for ground. Then anywhere in the dash harness that has that G-R will and can be your positive. But that empty unused connector that a couple of us have(pictured in that thread i linked) thats right there next to or around the back of the dimmer is the easiest was to go. That unused connector also has the W-G & the G-R to use if you like as well, so both wires(+ &-) will be on that empty connector. With your test light itll seem like both those wires are hot, but the ground has power too because there has to be somewhere for the power to go that is being unused when dimming and "throwing away" power.. hope that makes sense, hard for me to explain, i barely understand it myself so...but thats why you get the opposite dimming going on. Youre tapping into only one side of the dimming circuit then running a plain ole ground to complete it. It needs to be tapped into "above stream and down stream" of the dimmer knob.

 

YOU my FRIEND are AWESOME!!! I will read/sift through the link. I know about the wires that you speak of. I just unscrewed the potentiometer and measured voltages (btw, mine has 3x wires connecting directly TO the potentiometer... it's a Reg Cab 2.7L 4x4 Automatic). I started the truck (i.e. so I didn't have to hear the buzzer/beeping), turned the headlights ON, measured voltages, and one wire was a constant approx 14Vdc, the second wire was approx 14Vdc but went up/down in voltage as you turned the potentiometer, the third wire seemed to be GND (off the top of my head, I think it was a W-B, White/Black-stripe wire). This seemed to be, by far, the easiest way to tap into the dimmer switch and very easy to get to without having to take the whole cluster gauge assembly apart from the dash. Anyways, thank you very much and I will start reading.

Happy Wheel'n

 

UPDATE:
On my lunch break I was able to TEST the dimmer switch with the gauge lamp:
Power (red) wire for the lamp --> Green-Red wire
GND (black) wire for the lamp --> White-Green wire

Turn the dimmer control knob and your gauge lamp should go bright/dim at the same time as your instrument panel lights. Thank you very much for your help!!!

Happy Wheel'n

p.s.
Now to wash that engine bay finally!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Is it just me or does anyone else do multiple "projects" on their trucks and finishing them LITTLE-by-LITTLE