Printable Version of Topic
Click here to view this topic in its original format
914World.com _ 914World Garage _ 914/6 Tach not working
Posted by: Joe C Feb 29 2020, 04:48 PM
Does anyone know when Porsche stopped using the inline resistor for the tach on a six?
I have a very late production original '70 and I cant get the tach to work. I'm pretty sure there isn't a resistor on the relay board. Trying to determine if they went to the internal resistor in late '70 production.
Posted by: ClayPerrine Feb 29 2020, 06:38 PM
There is no resistor in a70 six, but there is a tach amplifier. It is located on the relay board. The amp was used to raise the CD box output to a level that would trigger the tach They were used in 70,but not in 71. Porsche got new circuit boards for the tachs in 70,and they used them in 911s first.
You can fix it by buying a tach for a 911SC, and transferring it's guts to the 70 914 tach. Then open the tach adapter and installing a jumper wire to bypass it. It will look stock, and the tach will work.
I can take pictures when I get home if you need them.
Posted by: Joe C Feb 29 2020, 07:10 PM
There is no resistor in a70 six, but there is a tach amplifier. It is located on the relay board. The amp was used to raise the CD box output to a level that would trigger the tach They were used in 70,but not in 71. Porsche got new circuit boards for the tachs in 70,and they used them in 911s first.
You can fix it by buying a tach for a 911SC, and transferring it's guts to the 70 914 tach. Then open the tach adapter and installing a jumper wire to bypass it. It will look stock, and the tach will work.
I can take pictures when I get home if you need them.
Pics would great, and thanks for the info!
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)