AEM Gauge Install

[Plastique_synthetiX]

I am currently in the midst of installing a pair of AEM gauges in my truck, but have not been able to find any definitive answers as to where the dimmer wire should be hooked up. Most posts that I have read say that when wired up to the stock "rheostat" (which I believe is actually a PWM) the aftermarket gauges are at full brightness when the dimmer is turned all the way down, and vice versa. Has anyone come up with a solution to this?

 

[Gadget]

Toyota normally uses a reversed ground system on many of their systems where the dimmer is on the ground side of the circuit and not the supply side. This means that the buss voltage will always be the same and the brightness is controlled by limiting the access to ground.

You can try measuring the voltage to the instrument lights and then finding a hot source of the same value and then running your ground wire into the circuit and see if it blows up or works.

G

 

[justin13703]

Usually hooking anything to the factory dimmer is a bad idea. What you will need to do will depend on if the gauges are meant to be variable dimmed (like your gauge lights) or if they have a preset "dim" level that they go to (like an aftermarket radio)

If its the second one it's easy, just hook it up to any wire that shows 12 volts when your parking lights are on. I believe you can get this at the headlight switch, the fuse box, and behind the radio. This will tell them the lights are on, and to drop to the dimmed brightness.

If they can be variably dimmed, you will need to find out weather they need a positive or negative signal, and then you will need to find a correct wire in the vehicle to tap to. Not all dimmers work by varying the power sent to the lights, some work by varying the ground side of the circuit. And then like you said some are a type of pulse signal.

All my aem gauges had a light sensor built in them to automatically dim. What is the model of the gauges you have?

 

[Plastique_synthetiX]

Thank you for your replies. The gauges that I have are models 30-3132 and 30-3133. Anyway, I believe that I have found the solution here: http://www.surrealmirage.com/vrg3/dimmer/