I have a 70 E Type ots. The tach has died. Is there anyway to test before pulling it out.
Can anyone recommend a reliable, reasonably priced rebuilder?
Thanks
GFB

Submitted by alan.barc@veri… on Sun, 01/15/2012 - 16:13

That's correct Gerald. Break the continuity of the white wires and the coil gets no power. This can be a very convenient circuit for installing an anti-theft cut-out switch.

Submitted by SW01-44661 on Sun, 01/15/2012 - 13:06

Ralph,
Thanks for the input. I have a impulse tach. Doesn't seem to be a test. Did note that the engine wouldn't start with the tach out unless the white leads were jumped.
Gerald.

Submitted by ralfecanelle@y… on Thu, 01/12/2012 - 17:55

this may come a little late...bu there is a testing process described in my manual where the tach is referred to as the revolution counter.the series one consists of an a.c. generatorfitted to the rear end of the camshaft with an indicator head mounted to the side facia panel. to test use an a.c. voltmeter to check current across the terminals of the generator at the rear of the right hand camshaft while the engine is running...when electrical current is evident check the continuity of the two leads by attaching the terminals to the generator and connecting the voltmeter to the opposite ends of the cables after removal from revolution counter. if when the engine is running continuity is evident, it can be assumed that the insturment is unserviceable. series 2 is described as an impulse tachometer with transistors and a printed circuit..the pulse lead--white-being wired with the s/w terminal on the ignition coil and the ignition switch. testing process is not mentioned specifically for this type of revolution counter.

Submitted by SW01-44661 on Mon, 01/09/2012 - 18:27

David, William,
Thanks for the input. The tach is now on its way to CA. Hope this the last time I have to Pull the top off the panel.
Regards,
Gerald Brinton
70 E-type OTC
Tucson, AZ

Submitted by bonnettoboot@e… on Thu, 01/05/2012 - 22:26

It would be helpful if folks asking these types of questions stated the city in which they live. I've been using West Valley Instruments, in Reseda CA, for over 30 years and recommend them

Submitted by DavidBarnes71@… on Thu, 01/05/2012 - 20:14

The tach in my '68 FHC is an inductive type that I think works off the "pulses" from the ignition system wiring. (I think the tach on the earlier cars works off a tach generator on the back of the cam). I do not see anyting in my book that talks about a way to test the inductive tach. My tach was way out of range when I bought my car in 2000. I sent it to Palo Alto Speedometer 650-323-0243. I think they rebuilt it for around $125 back then

David Barnes
'68 FHC