73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Interior & Equipment => Instrumentation => Topic started by: RGSMS on February 17, 2018, 01:33:00 PM

Title: Wiring a Tach on a TH400
Post by: RGSMS on February 17, 2018, 01:33:00 PM

Just got a new gauge cluster and it has a tach on. It (my old one never had one). I was wondering how to wire it from trans to gauge.


Sent from my iPhone using Tapatalk

Title: Re: Wiring a Tach on a TH400
Post by: Rapid Roy on February 17, 2018, 01:56:33 PM

Welcome to the site

Title: Re: Wiring a Tach on a TH400
Post by: bd on February 17, 2018, 02:06:05 PM

A tachometer (tach) registers engine RPM so has no connection to the transmission.  Pink to 12-volt ignition, black to ground, brown to the negative terminal of the coil (the TACH terminal of the distributor if HEI).

Title: Re: Wiring a Tach on a TH400
Post by: RGSMS on February 17, 2018, 09:08:24 PM

Ok awesome thanks guys


Sent from my iPhone using Tapatalk

Title: Re: Wiring a Tach on a TH400
Post by: 75gmck25 on February 18, 2018, 07:38:38 PM

Most auto parts stores sell the correct terminal that plugs directly into the tach connections on an HEI.  You need a connector similar to this one.  https://www.amazon.com/American-Autowire-500205-Distributor-Tachometer/dp/B003VXLOSU

You can make a female spade terminal work if you have to, but it is only kept in by the friction of the metal tab.

Bruce