Tachometer Question

[ABK1500]

Hey guys, this is my first post here, great site!

I don't own an S10, but I do have a 1998 K1500, which came from the factory with the 4.3 v6:confused: .
Anyway, I swapped in a 350 from another truck, and the tachometer isn't right. I was wondering if there was any way to get it to read right? Does anybody know how far the tach would be off?

Thanks for all of your help!

[spacecadet]

There is a diode for the tach to fix the tach being off. I think its in the Parts Store here on this site. If not the JTR site should have it.

Space
Bythe way welcome to the site!!!!

[355V8S10Tahoe]

Welcome to the site...

It should read 33 percent to high, 4,000 RPM would be around 3,000 RPM according to the JTR manual, and if the tach is similar to the S10 tach a polyester film capacitor can be changed on the circuit board in the tach to recalibrate it for a V8 but it depends on the year and if it's a digital dash, digital can't be re-calibrated in this way...

[harleyboy]

welcome to the site and enjoy your project, thats the reason I went with after market

[wild572s10]

Welcome to site. I also went with Auto Meter gauges. you may want to up grade membership so you can post more than once a day

[ABK1500]

I would like to try to get the stock tach to work if possible. So I have to wire in some resistors somewhere? Do I wire them into the wire, or do I have to do something to the cluster?

Any help would be appreciated.
Nice site too!

[Melonhead]

Try this.
http://www.s-series.org/htm/how2/recalibr.htm

[ABK1500]

Melonhead, great link. I guess my main question is, does anybody know if the s10 clusters and the fullsize clusters are the same. Or at least the tach wiring? I'm going to try to pump this out htis weekend.

[355V8S10Tahoe]

Your going to have to pull the gauge cluster to find out if no one can answer your question about them being the same, match the tach circuit board up to the pictures in that link Melonhead posted and you can find out for yourself, good luck with it being the same... That link was a better version of what I was trying to tell you before...

You could also just go to a junk yard, pull a gauge cluster out of a V8 truck similar to yours and yank the circuit board...

[ABK1500]

Okay I pulled the cluster today and it looks like this

http://i668.photobucket.com/albums/vv44/ABK1500/tacj.jpg

It looks like it says 510 ohm or something ike that under the resistor. Does this look familiar to anyone?

[Melonhead]

That resister looks like it goes to ether side of the battery light.

[ABK1500]

That resister looks like it goes to ether side of the battery light.

Yeah, my mistake. I just have another question. I was wondering if these resistors that need to be wired in, can I add them anywhere in the line (like by the distributor), or do I need to take apart the cluster?
I'm going to try to knock this out this weekend, does anybody have the size resistors in their head?

Thanks!

[Melonhead]

Check with Current Performace. They make a module to correct the tach on their wiring harnesses. They may sell the module to you at a price.