Upgrading to an Instrument Cluster with a Tachometer

[someotherguy]

92-94 are direct swaps. If you want the redline on the tach to be correct it'll have to come from another 454 truck. Otherwise just be sure it comes from another V8 gas engine truck.

If you want to calibrate the speedometer then you can easily modify your DRAC module behind the glovebox liner. That's where the configuration happens on 92-95 models (except 95 it's underneath the PCM bracket; a little more work to get to it.)

Richard

 

[cc333]

If you want to calibrate the speedometer then you can easily modify your DRAC module behind the glovebox liner.

OK, that seems easy enough. How do I program the DRAC module? Are there jumpers I set? DIP switches?? What does it look like???

92-94 are direct swaps. If you want the redline on the tach to be correct it'll have to come from another 454 truck. Otherwise just be sure it comes from another V8 gas engine truck.

OK, that's what I surmised, based on what I've read. I don't mind terribly if the redline's not in the right spot, but at least it'll read correctly otherwise (does the 454 have the redline at a lower or higher RPM?)

So, to do the swap, I undo the 4 torx bolts holding the bezel on, then the maybe another 4 or 6 bolts holding the cluster in place, then swap the wiring harness?

Thank you all for bearing with me, as I'm new at this!

c

 

[someotherguy]

Pretty much correct. If you're an automatic trans then be careful pulling the cluster away from the dash as there's a thin string attached from the shifter "collar" up to the gear indicator in the cluster. You simply unclip it from the shifter collar, note how it wraps around it, then it's pretty easy to re-install when you put the new cluster in. Adjusting it takes a little trial-and-error; I go for setting it to correct position in (OD) (key off, parking brake set, duh) since that's where you'll spend most of your time. The rest will be correct if OD is correct.

Also, be careful moving the dash bezel away from the dash, as the headlight switch is attached to the bezel, and the screw posts for it are almost always cracked or broken. Very fragile area so just take care. There's ways to repair those posts if needed...I used DevCon "plastic welder" epoxy squeezed into little forms I made from cut-up drinking straws, put the switch into place and installed the screws and let the epoxy set around 'em.

The DRAC module is a small circuit board inside a white plastic clamshell, little smaller than a deck of cards. It will have one or two banks of jumpers in it depending on the version. I find it best to replace those jumpers with DIP switches so it can be reconfigured at will, great for really getting it accurate (try several settings) or for tire size/gear ratio changes later.

Here's a pretty decent page describing the DRAC modification and settings: https://harristuning.com/Tbi/vssb-drac-calibration/

Richard

 

[cc333]

Oops! Reposted an old post for some reason.

I got the cluster from the 5.6 V8, so we'll see how it goes when I get it.

c

 

[cc333]

OK, I got the cluster, all dirty and stuff. It cleaned up nicely, but now I want to upgrade the backlighting.

Anyone know what kind of bulbs I need?

c

 

[cc333]

Hi all...

After a nearly 6 month absence, I'm back!

I'd moved house since my last post, so never had a chance to get back to this project because I was busy loading all our stuff into storage units....

I figured out the bulbs I need (there's a kit on eBay), now I need to figure out a couple things before I install:

1: How do I know if the gauges are properly zeroed out? If thery're not, is there a way to do it (probably pulling the needle off and replacing it in approximately the position it should be in, I guess?) Also, Is it possible to like rotate the gauges counter clockwise a rotation or two to zero them out? Or does that ruin them?
2: If when I install it I find that most of the gauges read inconsistently wrong such that simply placing the needle where it should be isn't enough, is there a way to fix them without getting another cluster, like with De-Ox-It or something?

I'm hoping to get to it to it sometime in January, once this rain stops; we here in California went from being historically dry with almost no rain whatsoever to historically wet with a seemingly endless stretch of rain starting later today and lasting possibly through New Year's, which makes it hard to do anything outdoors!

Oh, well, I'll take rain over fire any day!

c

 

[Lowstature]

I read this post and got all excited. I went to the local yard and saw a gauge set with a tach in it and the mileage was only 200 miles different from what my actual mileage was…/ a match made in heaven (so I thought)…. There was no engine or trans in the truck and I neglected to notice the diesel only written at the fuel gauge. Can’t believe I did that..:: yard doesn’t do returns, so I’m out 75 bucks for a gauge i can’t use. Lesson learned, check the fuel gauge BEFORE pulling.

 

[GoToGuy]

Does the diesel fuel level operate a great difference in impedance?

 

[Lowstature]

I'm not sure, but it would drive me nuts seeing that and knowing it's not correct. I think I read somewhere they were not interchangeable but even if they were I still wouldn't do it. There are a few things I'm a little critical of and that would be one. I can just see one of my teenage kids pump the wrong fuel in it because they don't ever listen to what I tell them. The joys of parenting.

 

[someotherguy]

Does the diesel fuel level operate a great difference in impedance?

I would wonder more if the tach signal was an issue.

Richard