Aftermarket Gauges Dim, why?

[Mark2]

I bought a 89 supra that has gauges installed for boost, EGR and Fuel Pressure. If I have them lit fully, then my stock gauges (eg. speedometer, rpm) go dim. If I put full lighting to the stock gauges, then the aftermarket gauges go dim. I'm using the dial that controls the dash lighting to do this.

Is there anyway to have both sets of gauges at full brightness. I have a feeling they may be wired up incorrectly.

Thanks,

Mark

 

[Mk3runner]

sounds like something is pulling too much juice.. a single 12 v source for all gauges... too much maybe.

 

[sneakypete]

yea sounds like they are all wired up to the same source. try wiring them up the the light around the ciggarette lighter illumination
-pete

 

[GC89]

wired wrong there should be a hot, a ground and a neutral. one wire will dim opposit and one will dim and brighten correctly when using the correct "ground source" play around with a test light, it will all make sense

 

[jdub]

LOL...this is as old as I am

The Supra dash lights are dimmed to "0" and the aftermarket gauges are dimmed to +12 volts...that means you have to vary voltage to the aftermarket gauges to get them to dim. If you wire them straight to 12 volts, they will not dim...if that's what you want, go for it. Otherwise, you will need a rheostat specifically for the non-stock gauges.

 

[GC89]

LOL...this is as old as I am

The Supra dash lights are dimmed to "0" and the aftermarket gauges are dimmed to +12 volts...that means you have to vary voltage to the aftermarket gauges to get them to dim. If you wire them straight to 12 volts, they will not dim...if that's what you want, go for it. Otherwise, you will need a rheostat specifically for the non-stock gauges.

My HKS gauges worked and dimmed perfectly :dunno: maybe Im just lucky with my guage type though

 

[jdub]

Perhaps I should have said "most aftermarket gauges to +12 volts"

In any case, the ones he has are doing exactly what I said...this problem has been around for a long time.

 

[mischief7m]

i have my aftermarket gauges wired to my light by the cig lighter (which is also connected to the stock rheostat) and they dim perfectly with the stock gauge lights.

they are leds' though (may make a difference idk)

 

[jdub]

It's great you guys have gauges that work with the stock dimmer wiring, but you are missing the point:

Aftermarket gauges bright = Stock gauges dim
Stock gauges bright = Aftermarket gauges dim

That is where I got my ID of the problem.
The only way a comparison is valid is if the gauges are the same as the OP...anything else is just adding confusion. That is unless he wants to replace his current gauges with ones that work the same as stock.

 

[Mark2]

LOL...this is as old as I am

The Supra dash lights are dimmed to "0" and the aftermarket gauges are dimmed to +12 volts...that means you have to vary voltage to the aftermarket gauges to get them to dim. If you wire them straight to 12 volts, they will not dim...if that's what you want, go for it. Otherwise, you will need a rheostat specifically for the non-stock gauges.

That is what I want. I want them to stay at their brightest all of the time. Would the light near the cigarette lighter be sufficient as a 12V source. Sorry, I'm clueless when it comes to wiring of any kind.

Thanks for the help guys.

 

[jdub]

The cig lighter light is wired to the stock dimmer...that will not do what you want. However, the wire powering the lighter itself will.

 

[Mark2]

I took the wire powering the cigarette lighter and used that as my power source for the gauges and it worked perfectly. Now the gauges are nice and bright.

Thanks!