csramsey640

Does anyone know if the Isspro tach harness for the 93's will work with any other tach than an Isspro? I think the Autometer is easier to read

wannadiesel

You could just get the AutoMeter 2888 (alternator tach). That's what I'm running.

csramsey640

what is the best location for those? I dont have an optical tach, so i wouldnt have much to go on. Are they easy to setup?

MBolivar

The only thing about Autometer tach #2888 is that the sensor probe is pretty particular about its placement. Works best at the 8 o'clock position along the middle of the alternator. Any diesel shop has an optical tach so you can calibrate it. I slipped on an available Autometer green bulb cover to match my stock gauges on the dash.

wannadiesel

Yeah, they are a little touchy about probe placement, but once you get it figured out they work well. I used a scan tool to calibrate mine, one of the nice things about '92's and '93's.

I mounted the tach on top of the column, as far right as possible. It blocks the high beam indicator and the numbers over 80 on the speedo.

MBolivar

Hey Dave,
Once your doing over 80, who cares?

wannadiesel

That's what I figured. If I can't see the needle I'm gonna get a big ticket no matter how fast I was going.

GreatWhite91

I was thinking about getting the alternator tach. Do they need to be calibrated, or is it just a clean install? I'm sure I could handle the installation, but haven't the slightest idea when it comes to doing a claibration.

How exactly does it measure the engine speed? Is the alternator spinning as fast as the engine, or is there an increase or decrease of the alternator RPM's due to different pully sizes.

Thanks for any comments, you guys are more than helpful

MBolivar

GreatWhite91,
The Autometer tach #2888 is a pretty straight forward installation. As mentioned earlier in this thread, probe placement is critical for it to work. Strap it at the 8 o'clock position along the middle of the alternator. The sensor probe picks up pulses from the alternator to get its reading. You will need to calibrate it after installation. Any diesel shop or automotive shop should have an optical tach. They'll put a piece of inductive tape on your crank pulley and use the optical tach like a timing light. A small precision type slotted screwdriver is what it takes to adjust a screw behind the Autometer tach itself to calibrate it to the same RPM as the optical tach. Typically, the shop tech will run the engine up to 1800-2200 RPM to get a more accurate calibration. Adjusting it at idle is not as accurate. Hope this sheds light on the subject.

GreatWhite91

Thanks a bunch! It was really bothering me that I didn't know how it worked. Makes total sense - going to order it.