Volt meter in boost spot

[Mk3 TurboS]

Ok so the title pretty much says it all, I know the topic was covered in the old SM but it hasn't been done here. As 90% have got aftermarket boost gauges I wanna replace the stock Boost gauge with the volt meter out of a NA. Now I know there was maybe a link or thread or write up on exactly how to do this but does any one know what it was? Danmcboost has the mod and im just curious as how hard, easy it is? Cheers :drink1:

 

[Idealsupra]

its not hard...it should fit perfectly in the boost location...and them simply hook up a constant 12v when the key is on...and your done

 

[keo]

sorry to bring back an old thread, i've search and this is the only thread that came up.
i want to do replace the factory boost with a n/a volt. i have a few good/junk clusters taking up space. lolz might as well do something useful with it.

anyways is it a plug and play, or do i have to rewire/reconnect some wires in the back of the cluster.
thanks for you help.

 

[got_boosted]

From my SF build thread.

I became unlazy enough today to pull my gauge cluster and swap my factory boost gauge for a volt-meter since yesterday I installed my -30 to +30 mechanical boost/vac gauge. It was easy enough.

Poor Supra.

The one closest is my original 91T cluster, and the other is a 90 N/A cluster that will be donating the volt-meter.

Volt-meter out!

I remember reading in the past that the volt-meter was a direct replacement for the factory boost guage, like all that needed to be done was pop the old one out and put the volt-meter in. Not so. The boost guage has this control box mounted at the back of the cluster that sends the signals to the boost gauge (white and yellow wires). This must be removed.

The printed circuit board was also slightly different. The positive signal to the guage was unchanged but the ground circuit was different, and I had to add my own. (Green wire)

And the finish product!

HTH

Collin

 

[KeithH]

Yep... very simple... Here's my writeup...

http://supras.org/keith/voltmeter.htm

 

[keo]

i will try that, thanks for all your help guys.
No wonder i come here more than Supraforums.(here is more helpful)

 

[RedGT]

I did the same on my car but I dident use a ground jumper at all.... Just removed the boost gauge box and plugged in the volt gauge... It works perfectly fine, you guys sure you need that jumper in there???

 

[KeithH]

Without the jumper you get no ground. No ground = no reading on the voltmeter. You had to do something.

 

[got_boosted]

Without the jumper you get no ground. No ground = no reading on the voltmeter. You had to do something.

I've heard others say this too. I'm wondering if some turbo boards had the ground built in like the N/A? I've only looked at 89+ boards so far.

Collin

 

[KeithH]

Take a look at the area around the lower point of the jumper wire in the pics above. There are no paths leading to or from that point. This is one of the two connections for the voltmeter. If you don't create a full circuit then you won't get a working voltmeter.

 

[RedGT]

I've heard others say this too. I'm wondering if some turbo boards had the ground built in like the N/A? I've only looked at 89+ boards so far.

Collin

Oh! thats probably it, I think I may have used the N/A circuit board on the back. I did a N/A-T swap and just made 2 clusters into one... And by the way, I do know a thing or two about electronic circuits, I am ASE master tech and L1 certified. I just dident realize the turbo and N/A boards were different. Sorry for the mixup!

 

[gtsfirefighter]

On my 87 turbo cluster, I dropped in a voltmeter from my 86.5. I did not have to do anything special to make it work. No jumper wire...nothing.

 

[A70BoosTFienD]

i did this for my 88 T but no dice, was gonna try the jumper next

 

[akito]

Did that to my 91 last year, forgot the jumper cable and no, it didn't work.

 

[MarkIII4Me]

I did this mod a few years ago on a 90T and used the jumper wire. It seems to work just fine except that the gauge jumps from 12-13, back and forth, when the turn signals are on. Does not fluctuate otherwise. I've taken voltage readings at the battery with and without the flashers on and there's no change. Any ideas?

 

[A70BoosTFienD]

im thinking its ground related. thats the only thing that comes to mind.

I just added the jumper and it works fine