Re: 67-72 Electric speedo
 

Finally got this speedo completed! After reading through this thread about 100 times no exaggeration, and asking tons questions I have it completed! A couple things I did a little different was powder coating the tins since I have the equipment and cutting a hole for the tach and clock and welding a trim ring to keep the factory look.

I haven’t put the ls engine in my truck yet and I’m going to wait until the engine is in to install the new cluster. To check my work before installing, I unplugged the factory plug from the cluster that is in the truck now and used alligator clips to connect from various pins in the factory plug to the lights and gauges in the new cluster. The only thing that I haven’t tried is the speedo which is most important. So super excited to try it out. Thanks to Eric and Tom for answering all of my novice questions! I was disappointed in my painting skills, a couple of the numbers didn’t turn out the best, I should have took the decal off sooner. This project defiantly tested my patience!

Re: 67-72 Electric speedo
 

Another helpful thing I found was this diagram of the color of wires in the factory plug. Also a pic of the cluster light up with LED bulbs

Re: 67-72 Electric speedo
 

Just checking in if anyone has this swap working with a Gen IV engine? I've got an 09 4.8 going into my 72 C20 and was contemplating this gauge swap, but saw that it might not work. Thanks from social distancing in Toronto.

Re: 67-72 Electric speedo
 

I have not personally messed with a lot of GenIV engines, other than one L99, but from what I have read, they don't have a dedicated speed signal going to the instrument cluster as its all on the CAN bus. When I did the L99 harness I believe there was a place to add a wire for a speedo but you needed to have it programmed to work, which we didn't do. So unless you can figure out that way to get that signal out of the ECM, then I am going to guess that this wont work for you.

Re: 67-72 Electric speedo
 

Not directly a solution but good info none the less.


http://automobileman.com/wp/?p=842

Re: 67-72 Electric speedo
 

If your setup uses an e38 ECM, VSS out is pin 57 on connector 1. By default, it’ll be 128k PPM (originally went to the antilock brake controller), but it can be changed to 4K PPM in the tune. The 4k signal will work fine with the S10 speedometer.

Re: 67-72 Electric speedo
 

Thanks for the info dayj1!

ls1nova71 - are the kits still available? I sent you a PM but haven't heard back. Thanks.

How can you get the mileage to match current speedo?
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Re: 67-72 Electric speedo
 

I'd be interested if lens kits are still available.

Thanks

Re: 67-72 Electric speedo
 

I am currently working on the wiring for my speedo swap and it appears in the photos that a relay is used in conjunction with the volt meter. Is that required?

As to Prodjays question about the odometer I just reset mine yesterday. It's a little tediuos but it's not that diffucult.

Re: 67-72 Electric speedo
 

No relay is required for the voltmeter. That relay in the pic was part of an automatic headlight set up that truck had.

I don't really know how to explain it, but you just kind of have to mess with it a bit. Once you take it out and play with it, i think you'll see how its done.

Re: 67-72 Electric speedo
 

Thanks to Ls1Nova71 I have started on my Squarebody swap to digital, even though I don't need it yet. Look at how close the S10-Speedo lines up with the Squarebody speedo bezel. Looks like the only thing I will have to modify is the odometer hole as it is a tad too small for the Odometer out of the S10.

The screw holes to mount the digital speedo even line up!

Re: 67-72 Electric speedo
 

You should be able to move the numbers for the odometer over by sliding them on the shaft they're mounted on. Just have to be sure the gear on the end still makes contact with the drive motor. If it doesn't, you can add another gear to it.

Re: 67-72 Electric speedo
 

Would the scale/ratio be correct?

Re: 67-72 Electric speedo
 

Not to step on lutronjim's question but I need help. I just completed my conversion and was able to bench test my dash lights, volt meter , etc. I couldn't bench test the speedo. So, today I layed my new cluster in the seat hooked 12 volt ignition, a ground and the wire coming from the PCM to the speedo and took it out. Nothing. The needle didn't move at all. I then disconnected everything and hooked my meter to the wire from the PCM and test drove it. At idle 0 volts. As I drove the voltage increased to a max of 6.6 volts at appx. 35 m.p.h. Any thoughts? Thanks

Re: 67-72 Electric speedo
 

Probably not, that's why i had to redo the face. 60mph needs to be straight up.

So all the other gauges work? Did the odometer work at all? If it did, then the stepper motor for the speedo needle could be bad, or if you painted it, it could be stuck to the stopper the needle rests on when the ignition is off. Did you put the needle on with the ignition powered up so you know the needle is resting at 0mph?

Re: 67-72 Electric speedo
 

Thanks for the suggestions.
1. I did not drive it far enough or even think to look at the odometer
2. I did paint the needle but it was off for at least a couple of weeks before I reinstalled it.
3. I did not install the needle with it powered up but when I received the S-10 cluster from E-Bay the needle wasn't at zero so I powered it up and it went to zero. Before I insalled the C-10 needle I powered it up and watched to see if I could see the shaft turn. I didn't see any movement so assumed it was zeroed, if that's a word, out.

So, I'll check all of these things out and get back. Perhaps when I powered it up and didn't think I saw movement of the shaft it is so slight that I couldn't see it move and then when I disconnected power it went back.

Again,

Thanks

Re: 67-72 Electric speedo
 

It's absolutely imperative that you install the needle with the speedometer powered up. You likely won't see the shaft of the motor move since it's small and the movement isn't a lot at times. Even if it was at zero powered off, just the act of installing the needle could move it enough for the needle to be off by a bit. Also, when installing it powered up, there's a chance you won't get it right on the first try, so it takes some trial and error to get it perfect.

As for painting the needle, for some reason it doesn't always matter how dry the paint is, it can still stick to the little needle stop if there's paint on the needle at that spot, because the stepper motors don't have enough power to overcome it even it is only slightly stuck. What I do is carefully take a razor blade and scrape the paint off the needle at that spot so it can't stick to it.

Re: 67-72 Electric speedo
 

Update time. After implementing your suggestions I have made a little progress, I think.

1. Both the regular odometer and trip odometer are working

2. The needle will move up to about 5 mph and that's as far as it goes

3. After coming to a stop the needle will not return to zero.

4. With the truck idling, in park, if I remove the needle, reinstall the needle at zero it does the same thing. Moves up to about 5 mph stops and doesn't return to zero.

Anymore ideas?

Thanks

Re: 67-72 Electric speedo
 

Is the needle hitting anything? Even something small can stop the needle. Make sure the needle goes through its full sweep without touching anything.

Re: 67-72 Electric speedo
 

Success!!!!!!

You were spot on. The new speedo overlay was covering up part of the hole where the needle goes thru and the needle was ever so slightly rubbing the "Shaft" of the needle. I used my Xacto knife, trimmed it back , powered the cluster up, reinstalled the needle and took it out for a test drive. It swept up smoothly and returned to rest just shy of the stop.

Now if I can install the cluster in the tub and bezel without screwing it up I'll be happy!!!!LOL

Again, THANKS !!!!

You are the MAN.....

Re: 67-72 Electric speedo
 

Cool! Glad you got it working.

Re: 67-72 Electric speedo
 

As a new '78 Squarebody owner, I am very interested in knowing everything that's going on here. Please let me know.

Re: 67-72 Electric speedo
 

Well I thought some people might be interested in a update. I have completed my electric con version and it works great!!!! My biggest disappointment is in the way I painted the numbers on the face. LS1Nova71 was very clear about painting the numbers and doing light coats. I did light coats but using the "If a little is good a lot is better" mentality, the heavy coats resulted in some paint bleeding under the stencil on a few numbers and they didn't come out as crisp and sharp as LS1 Nova71's.

Also, on the temperature gauge I ended up adding in I think 7ohms of resistance to get the needle to read in the normal range at normal operating temperature.

So, all in all I really enjoyed working on it, it works great (and accurately) and love it when a few people that has seen it says "I didn't know these trucks had a 120MPH speedometer" LOL!!!

Again thanks to LS1Nova71 for all of his help and I'd do another one if I get the chance.

Re: 67-72 Electric speedo
 

I want a speedo decal.

Re: 67-72 Electric speedo
 

Thanks for the update and kind words. Glad you got it done and working. :metal:

PM sent

Re: 67-72 Electric speedo
 

do you have any more kits if so i would like 3 of them Thanks

Re: 67-72 Electric speedo
 

Hello, Eric (and others who have contributed to this thread). It is getting close to 10 years since Eric started this and guys are still doing this conversion! What a great thread!

Eric, if the face and stencil stickers kits are still available, I would like to have 3 of them. Pleas let me know. Thanks.

Re: 67-72 Electric speedo
 

Wow, kind of hard to wrap my head around the fact that this thread is almost 10 years old! Geez, time flies!

I sent you a PM

Re: 67-72 Electric speedo
 

Hi Eric,

I would be interested in buying 2 of your overlay, stencil, and template kits if you have any available.

I just checked and it was 2013 when I bought one of your cruise control / turn signal levers for my '71. With that part and your "LS factory cruise control hook up" posts, I've had "factory" retrofitted cruise working in my truck since. Probably one of the best upgrades i ever made to it.

Thanks,
Don

Re: 67-72 Electric speedo
 

Hey Eric, I could use a decal set also...Thanks Ed.

Re: 67-72 Electric speedo
 

Glad to see this thread still alive. I am starting to work on project again - lost my wife and am having a hard time getting anything going.

I am old with tremors and I knew I could't glue the S10 shaft onto C10 needle. I took a different approach. I drilled thru the cylinder where you attach the needle through the top with a drill the same size as the s10 stepper. I then drilled through the top with a drill sized like the C10 needle shaft. I then cut off the shaft to make a 'coupling adapter'. Put it on the C10 needle with a dab of glue.

This keeps the C10 with its correct counter weight. When I put it on the S10 speedo, it appears to have about the same space from the plate as the C10.

I ordered the red led from Radio Shack for the high beam indicator. They must have a different China supplier. While the mount appears to be the same as the thread pictues, it is too long to go between the odometer mechanism and plate. I have some small short red leds that I am going to have to come up with some way to mount.

Re: 67-72 Electric speedo
 

This looks like a good alternative to epoxy holding the center in place. Thanks

Re: 67-72 Electric speedo
 

I'll take 2 more sets, if available

Re: 67-72 Electric speedo
 

Would a 1995 S 10 speedo work? They are listed as being the same from 95-97 from what I can tell.

Re: 67-72 Electric speedo
 

Page 17 if it's a 100 mph speedo it will work.

Re: 67-72 Electric speedo
 

I'm back in town now and put an order in for more stencils and gauge faces. I will let everyone know when I get them. Thanks.

Re: 67-72 Electric speedo
 

I need a gauge face too? I just got my S10 speedo and will start on this soon. I suppose I could use my 2014 GMC to check and see if it works?

Re: 67-72 Electric speedo
 

I started my dash and was having trouble lining the speedo numbers up to the marked locations. I could get 120 and 60 to line up decent but the MPH was off a hair and the 0 was way off. I was using a repop dash lens so I found a used lens to help locate the sticker. It was actually pretty easy after that because I could see the numbers without holding it to the light. I laid the number sticker on the new lens and set the old lens on the top. I aligned both lenses edge to edge and then aligned the numbers on the sticker to the old lens. The trickiest part was lifting the old lens to tape the sticker without moving it but I simply laid it back on top to make sure it didn't move. The 0 on the repop lens was off by at least 3/8 of an inch. Hope this helps someone else.

Re: 67-72 Electric speedo
 

I would like to purchase 2 sets when available, Thank you!