Pennock's Fiero Forum
  Technical Discussion & Questions
  sunbird tach mod

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
sunbird tach mod by vette7584
Started on: 12-15-2014 10:45 AM
Replies: 2 (618 views)
Last post by: Irrationable on 12-15-2014 01:28 PM
vette7584
Member
Posts: 504
From: schaghticoke ny usa
Registered: Jul 2014


Feedback score: (3)
Leave feedback

Rate this member

Report this Post12-15-2014 10:45 AM Click Here to See the Profile for vette7584Send a Private Message to vette7584Edit/Delete MessageReply w/QuoteDirect Link to This Post
can anyone help, please? i want to install the sunbird tach into my 1988 with 3800sc. what i need to know is what i need to modify the tach. i have seen threads that say 1meg ohm trimmer pot, well i went to the local radio shack and bought what i thought was the right part, was told its not. thats fine, i do not know or pretend to know anything about electronics. i have looked on a website for a place called frys, well, theres thousands of listings, so what i am asking is can anyone just please give me a part number on the part they used? i would really appreciate it. thanks
IP: Logged
PFF
System Bot
Irrationable
Member
Posts: 406
From: Raleigh, NC
Registered: Dec 2014


Feedback score:    (15)
Leave feedback

Rate this member

Report this Post12-15-2014 01:22 PM Click Here to See the Profile for IrrationableSend a Private Message to IrrationableEdit/Delete MessageReply w/QuoteDirect Link to This Post
I JUST finished installing a sunbird tach myself. The resistance needed to properly calibrate the tach is around 200,000 ohms, or 200kohms. A variable resistance trimmer aka potentiometer is needed to fine tune this resistance so that your tachometer reads exactly as it should.

1 meg ohm is equal to 1,000,000 ohms. So, a 1 meg trimmer can be adjusted from 0 to 1million ohms. Basically, you need any trimmer that exceeds 200k.

For my tach, I ordered this trimmer assortment off of ebay. Both the 1meg and 500k timmers in this assortment will fit your needs. I opted to use the 500k as it gave me a greater degree of adjustment to fine tune my tach readout. Each trimmer has 25 turns between full resistance and zero resistance, the closer the resistance is to what you need, the greater degree of adjustment you'll get for each turn of the screw on the trimmer.

------------------
"The Twins"
'87 GT 3.4 pushrod daily driver
'88 GT 3.4 DOHC swap in progress

IP: Logged
Irrationable
Member
Posts: 406
From: Raleigh, NC
Registered: Dec 2014


Feedback score:    (15)
Leave feedback

Rate this member

Report this Post12-15-2014 01:28 PM Click Here to See the Profile for IrrationableSend a Private Message to IrrationableEdit/Delete MessageReply w/QuoteDirect Link to This Post

Irrationable

406 posts
Member since Dec 2014
This is the how-to guide here on the forums that I used to install my tachometer. https://www.fiero.nl/forum/A...130314-2-110302.html

Also, a helpful tip that I learned the hard way: when you solder the leads to your trimmer. solder them to the FIRST and SECOND pins of the trimmer. If you use the first and third pins, you get full resistance with no adjustment. It took me almost an hour to realize what I had done wrong when I was installing mine.

------------------
"The Twins"
'87 GT 3.4 pushrod daily driver
'88 GT 3.4 DOHC swap in progress

IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock