TGP Cluster Idea

[RareGMFan]

I don't know if this has ever been brought up, or suggested, but I certainly don't remember coming across it, and nokicker's cluster pic reminded me, so here it goes. Between it being a pain to find a TGP cluster with a functioning speedo/tach for these cars, and wishing there was a voltage gauge, I thought of a different approach. Since the boost gauge that we loose the volts gauge for is useless, and people wined up going with aftermarket boost gauges in the pillar pods anyway (which I plan to do if I keep the car), what if I used the cluster from a regular GP? Hopefully, I'm right in assuming it would just take swapping a wire in the pin-out, or something, to get a voltage reading. And while they still have similar issues, I'm sure it would be much easier to find one with a functioning speedo/tach than a TGP. And then I'd get a graphics place to make me up a new faceplate with the same "Turbo INTERCOOLED" insignia so I could still retain that. Can't go around not having that thing light up at night.

 

So what do you think? Feasible? Logical? Any problems that might arise from this?

[digitaloutsider]

Don't the TGP clusters have like a whole additional plug with a blue wire for the boost gauge?

[Jeff M]

But do we know that the standard GP analog cluster is any more reliable? Quick look at the back of each gauge cluster circuit board markings would give a better idea if they were made by the same manufacturer, and having someone that frequents the pure W-body side enough to know what appears to be thought common here as in gauges a problem for the majority .

 

Shawn Linn has a very detailed web page on simple repairs to correct inaccuracies with the gauge cluster, might be less work. Do the repairs work for everyone??....no real confirmation yet as no one reports back that it worked or not, seems once fixed they got what they wanted?

 

Jeff M

[RareGMFan]

Well, I partially addressed the realiability issue:

 

And while they still have similar issues, I'm sure it would be much easier to find one with a functioning speedo/tach than a TGP.

 

Since I'd have the pick of the litter with regular GP clusters, I'm sure I could come across a fairly accurate one. Though I don't recall seeing too many regular GP owners complaining about the speedo/tach.

 

I've seen a fix for the "check gauges/low fuel" lights problem on Shawn's site, but I don't remember anything about the accuracy of the speedo/tach. As for the other fix, from what I've read, that seems to cure it most of the time.

 

But even if the clusters didn't have these problems, there's the issue of the pointless boost gauge. If you want any kind of accurate numbers, you need to go aftermarket anyway. And that pointless gauge sitting there cost us the volts gauge, which I'd love to have. So I thought this was the best way to cure MULTIPLE problems in one shot. More accuracy, a more usefull gauge (volts), and all we'd be loosing is the useless boost gauge. A few bucks to recreate the faceplate for this cluster, but with the same "Turbo Intercooled" insignia, and it will still have a clean, factory feel/look.

 

Digi - I'll have to check the wiring diagrams on what goes where, and see where the volts wire is located on the ordinary cluster.

[Dark Ride]

I made a topic about this prolly about a year ago now

 

I took a Regular GP cluster, removed the circuit board and swapped the circuit boards with one from the TGP, plugged the Regular Gp Cluster with the TGP Face(Including Intercooled Turbo Logo) and woo hoo I now have a functioning cluster with a voltmeter. However, I tried to take the voltmeter section of the face off the Regular GP and put it into the TGP and tried to make it look factory but it didn't work so well. The Only other foreseeable problem is swapping the faceplate(the piece that peels off that says everything on it) is that you have to take off the knobs, and when I did this with oil pressure and volts they were off horribly and I had to calibrate volts with an actual voltmeter and i just guessed for oil pressure. I figured I worry about it once I actually get close to driving this car.

 

I am extremely interested in Getting a good, working, calibrated gauge cluster with the Intercooled Turbo and Premium Unleaded Fuel Only. If Someone could make a good gauge faceplate then that would be an excellent place to start. I'm curious to see where this goes.

 

-Mitch

[Crazy K]

I made a topic about this prolly about a year ago now

 

I took a Regular GP cluster, removed the circuit board and swapped the circuit boards with one from the TGP, plugged the Regular Gp Cluster with the TGP Face(Including Intercooled Turbo Logo) and woo hoo I now have a functioning cluster with a voltmeter. However, I tried to take the voltmeter section of the face off the Regular GP and put it into the TGP and tried to make it look factory but it didn't work so well. The Only other foreseeable problem is swapping the faceplate(the piece that peels off that says everything on it) is that you have to take off the knobs, and when I did this with oil pressure and volts they were off horribly and I had to calibrate volts with an actual voltmeter and i just guessed for oil pressure. I figured I worry about it once I actually get close to driving this car.

 

I am extremely interested in Getting a good, working, calibrated gauge cluster with the Intercooled Turbo and Premium Unleaded Fuel Only. If Someone could make a good gauge faceplate then that would be an excellent place to start. I'm curious to see where this goes.

 

-Mitch

interesting! the boost guage would be an unmarked voltmeter if you did not chnge the markings.

but does it change the guage calibrations?

[GOT2B GM]

swap in a 88/89 GP digital cluster. THAT would be cool.

[GutlessSupreme]

eh I'm not a big fan of the digital GP clusters.

 

i've thought about this same thing for a while though.. I just didn't want to lose the lit up Turbo Intercooled logo

 

[RareGMFan]

eh I'm not a big fan of the digital GP clusters.

 

Me neither. If it was ENTIRELY digital, like the 6000 STE, I'd be all for it. But I'm not a fan of the way they designed the GP digital cluster.

 

i've thought about this same thing for a while though.. I just didn't want to lose the lit up Turbo Intercooled logo

 

Precisely why I'm having a new faceplate made. They do it all the time for aluminum, or white gauges, etc, so I'm sure just replicating the regular GP faceplate, except with the Turbo Intercooled insignia would be a breeze. That would be the last thing to hold me back from doing this. And since Dark Ride got his to work, I'm pretty much positive I'm going this route if I keep the TGP. But....do you really need to change the circuit boards? I would think it would just be plug and play, minus finding the correct pin-out/wire for the volt gauge.

[Dark Ride]

 

i've thought about this same thing for a while though.. I just didn't want to lose the lit up Turbo Intercooled logo

 

Precisely why I'm having a new faceplate made. They do it all the time for aluminum, or white gauges, etc, so I'm sure just replicating the regular GP faceplate, except with the Turbo Intercooled insignia would be a breeze. That would be the last thing to hold me back from doing this. And since Dark Ride got his to work, I'm pretty much positive I'm going this route if I keep the TGP. But....do you really need to change the circuit boards? I would think it would just be plug and play, minus finding the correct pin-out/wire for the volt gauge.

 

There isn't a pin-out for the volt gauge, it gets the reading off of one of the three hots that go to the cluster, I thought it was IGN, but it could've been INDIC. Thats why I had to switch circuit boards. If You Get a new faceplate made you should get two and ill buy the second one.

[digitaloutsider]

swap in a 88/89 GP digital cluster. THAT would be cool.

 

Okay, Ross.

 

 

 

 

 

 

 

[GOT2B GM]

Hey now!

 

But seriously it would match the car well.

[89GP_SE]

a guy on clup gp did a swap from his analog gauges to digital. im pretty sure that the pinouts are different

[Dark Ride]

I Really Like The Look of the GPs Analog Gauges

[Addicted To Boost]

I Really Like The Look of the GPs Analog Gauges

x2

[GnatGoSplat]

Shawn Linn has a very detailed web page on simple repairs to correct inaccuracies with the gauge cluster, might be less work. Do the repairs work for everyone??....no real confirmation yet as no one reports back that it worked or not, seems once fixed they got what they wanted?

 

I have heard back from a handful of people that actually tried it and managed to fix their gauge inaccuracy. I forgot who they were though, it's been a few years!

 

I had once thought that I would just fine tune the boost gauge to make it accurate, then add a small digital display in the cluster for a voltmeter.

 

[Dark Ride]

What Exactly Needs To Be Done to get our speedos and tachs to be accurate? Also, I'm really curious about getting a new gauge overlay.

[Q-Ball]

I swapped my regular 92 GP guage for a 89-89 Digital. Everything works, except mines stuck in MPH (I need KM) Same thing with the HUD. But everything does work though.

[digitaloutsider]

There's a wire you need to ground. That'll switch it to metric. At least, that's how the HUD's work. I'd imagine the clusters are the same way.

[Q-Ball]

Yeah thats what I've been told. I guess I would have to ground 2 wires to the ground? 1 for Cluster and 1 for the HUD? I was also reading in my car's manual a while back and it said to change the hud from mph to km is done in the DIC. Only problem is, I dont have my DIC connected. When it comes to my car's wiring, I really hate it.

[gimper]

Hello,

 

The repair on Shawns page works in regards to low fuel/check gauges always on. I actually remade ever solder on the board - sure brute force but it worked. It didn't solve the problem with the speedo/tach although.

 

Shawn you said you adjusted fixed your speedo/tach -- do you have a description / picture etc?

 

Cheers Gimper

 

Shawn Linn has a very detailed web page on simple repairs to correct inaccuracies with the gauge cluster, might be less work. Do the repairs work for everyone??....no real confirmation yet as no one reports back that it worked or not, seems once fixed they got what they wanted?

 

I have heard back from a handful of people that actually tried it and managed to fix their gauge inaccuracy. I forgot who they were though, it's been a few years!

 

I had once thought that I would just fine tune the boost gauge to make it accurate, then add a small digital display in the cluster for a voltmeter.

 

[GnatGoSplat]

Shawn you said you adjusted fixed your speedo/tach -- do you have a description / picture etc?

 

I thought I had a writeup on the site, but I checked and didn't find it. I guess I must have dreamed it!

 

Anyway, there is a white ceramic 14-pin(?) chip. It's not really a chip, but just a piece of ceramic with a black resistor painted on it. If you look carefully, you'll see a cut line in the resistor. That's how it was fine-tuned, the deeper the cut, the less the resistance. Laser-etched resistor I think it's called. Anyway, my theory is over time, the resistor degrades and the resistance increases. The way I fixed it, was I attached a 1-megohm (or was it 10-megohm?) resistor across the original laser-etched resistor in parallel. Basically, one leg of my resistor I soldered to the pin connecting to the laser-etched resistor, and the other leg of my resistor I soldered to the other pin of the laser-etched resistor.

 

That gave me perfect accuracy. At first, I thought it might be better to use a tiny adjustable trimpot for fine-tuning, but the fixed resistor I used worked perfectly. I'm not sure if the same value will fix most peoples' dashes, maybe I just got lucky.

 

I'll see if I can dig up pics. I'd like to think I took pics of the actual mod, but not sure if I did.

 

[gimper]

 

I thought I had a writeup on the site, but I checked and didn't find it. I guess I must have dreamed it!

 

yea its always easier to dream it, I wish I could dream fix my car. Definitly less dirt under my finger nails that way...

 

Anyway, there is a white ceramic 14-pin(?) chip. It's not really a chip, but just a piece of ceramic with a black resistor painted on it. If you look carefully, you'll see a cut line in the resistor. That's how it was fine-tuned, the deeper the cut, the less the resistance. Laser-etched resistor I think it's called. Anyway, my theory is over time, the resistor degrades and the resistance increases. The way I fixed it, was I attached a 1-megohm (or was it 10-megohm?) resistor across the original laser-etched resistor in parallel. Basically, one leg of my resistor I soldered to the pin connecting to the laser-etched resistor, and the other leg of my resistor I soldered to the other pin of the laser-etched resistor.

 

Makes perfect sense, both your theory why it gets inaccurate and also the fix. Hmm maybe you could clean the oxidation off the original resistor although I doubt that it will work but it’s worth a shot. The fix is a definite fix, since R = 1/(1/R1 + 1/R2 …) when you parallel two or more resistors the resistance will always be less than the smallest resistor. Hence it can be a good idea to messure the resistance on the original and then get a pot that you can adjust from say 1/2 old R to nearly old R.

 

 

That gave me perfect accuracy. At first, I thought it might be better to use a tiny adjustable trimpot for fine-tuning, but the fixed resistor I used worked perfectly. I'm not sure if the same value will fix most peoples' dashes, maybe I just got lucky.

 

I'll see if I can dig up pics. I'd like to think I took pics of the actual mod, but not sure if I did.

 

 

Pretty sure your value will not give anybody else oefect accuracy. I mean they have different amount of inaccuracy and they are also most likely finetuned differently when new. It could although be interesting to know since it will give people a clue what kind of pot to buy.

 

Cheers Gimper

 

PS: Pic would be nice but I know what component you are talking about -- but it might help other w-body folks.

[TurboGTU]

From the Sunbirds boost and Tach...they used the same Driver(chip)and pointing gyro, only the circuts are different. SO you can't just plug the volt guage to the map sensor. It'll keep reading less than 9 volts. I'll look at it closer. It uses different resistors and a capacitor. Just change the less than $5 of resistors and caps.

[Dark Ride]

Shawn you said you adjusted fixed your speedo/tach -- do you have a description / picture etc?

 

I thought I had a writeup on the site, but I checked and didn't find it. I guess I must have dreamed it!

 

Anyway, there is a white ceramic 14-pin(?) chip. It's not really a chip, but just a piece of ceramic with a black resistor painted on it. If you look carefully, you'll see a cut line in the resistor. That's how it was fine-tuned, the deeper the cut, the less the resistance. Laser-etched resistor I think it's called. Anyway, my theory is over time, the resistor degrades and the resistance increases. The way I fixed it, was I attached a 1-megohm (or was it 10-megohm?) resistor across the original laser-etched resistor in parallel. Basically, one leg of my resistor I soldered to the pin connecting to the laser-etched resistor, and the other leg of my resistor I soldered to the other pin of the laser-etched resistor.

 

That gave me perfect accuracy. At first, I thought it might be better to use a tiny adjustable trimpot for fine-tuning, but the fixed resistor I used worked perfectly. I'm not sure if the same value will fix most peoples' dashes, maybe I just got lucky.

 

I'll see if I can dig up pics. I'd like to think I took pics of the actual mod, but not sure if I did.

 

Thanks, i was really curious as to what was involved in fixing it, Once It warms up outside i'm gonna take a look at it, I don't understand a lot about resistance. So the more resistance added the faster or slower the speedo reads?