[jciwolf]

My 1970 GTO/400 is equipped with a HEI distributor, probably modified by 2nd owner, and it had a wire from the cap "B" terminal going through, what once was the clutch pedal hole on the firewall, to the downshift switch on the steering column. The switch was also disconnected and jumpered across. I can only think of this was one way of getting power to the "B" terrminal. The same "B" terminal on the distributor cap has 12volts on it at all times without the key in the switch, which I understand should not be. Can anyone help me figure out why this was wired this way or which way it should be wired. I have been advised to wire a inline 25 amp fuse to the fuse panel on the engine side but no diagram or hint as to where. I realize this is pretty winded of a question but I don't know how else to put this on email. thank you jciwolf

[Txbobcat]

Run a wire from an extra terminal off of the fuse box that is hot with the key on and off when key is off. No way to figure why a nut wired your car this way

[jciwolf]

thank you for the advice. I will give this a try and let you know. While I have you, I also found a pair of wires black and blue with a 150 ohm resistor across them on one side of the connector, just tied off to the firewall. Any idea what these where for? The cars runs without them connected to anything? thanks again jciwolf

[Txbobcat]

Sorry dont know the answer to that

[jciwolf]

thanks anyway, it's great to have honesty and knowledge, which you seem to have both.

[jciwolf]

back to my HEI distributor. Does any one know what the "T" terminal is for on the distributor cap? I am guessing it means tach but I haven't as yet found anything specific
, such as what and why. I appreciate all the help. By the way the relay wiring for the "B" terminal worked fine. thanks all

[george kujanski]

T is for tach.

George

[jciwolf]

I thank you for the reply. I still don't know what the purpose of this terminal if. Does it give out a graduated voltage for RPM reading or what exact purpose is it for and how do I hook it up.

[Ollie]

Some models have a tach, or optional tach. Trans Am's for example. The in dash tach connected to that terminal.

[jciwolf]

I thank you for the response but how do I connect to this terminal? Obviously with the proper 1/4" connector and wire, but what do I connect it to. Is there a voltage or millivolt signal from this or is it strictly any tach out there would work? Sorry to sound like a dummie but this is my first rebuild and I want to get it right the "first time". Thanks

[george kujanski]

The signal is a pulse train whose frequency increases with rpm. A tach take this signal. And coverts it to a current that drives a meter

tachs have a tach input where this signal is connected.

George

[jciwolf]

Thanks George, I will try this out, hopefully the tach I have on a shelf works. By the way I lived in Des Plaines until the early 70's