Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, there is shown a block diagram of a remote automobile starter system incorporating a diagnostic circuit. FIG. 1 shows various remote automobile starter elements whose outputs are fed into a control logic circuit 70 of a remote automobile starter unit. These various remote automobile starter elements include a voltage regulator 10, a tachometer 20, a hood sensor 40, a brake sensor 50, and a neutral safety switch sensor 60. Also input into the control circuit 70 of the remote automobile starter unit is a remote control input 30 which receives a signal indicating that the car is to be remotely started. An output from the control circuit 70 is fed to a set of output relays 80 and to the diagnostic circuit 90. The set of output relays 80 is also connected to the diagnostic circuit 90. The output relays 80, then, are connected to the appropriate automobile circuits.
FIG. 4 details the unique "tach" LED circuit of the present invention. This circuit is designed so that the LED is off at 1000 rpms, glows dimly at 2000 rpms and is at full brightness at 3000 rpms. Thus, when the car is running, the installer can push the gas pedal down and quickly verify that the remote automobile starter unit is reading the correct rpm rate.
A third object of this invention is to provide a novel manual car self-disablement circuit which causes a remote automobile starter to self-disable itself if it sees that it has been installed in a manual transmission car.
The tach input for a remote automobile starter unit may be an inductive pick up arrangement that clamps around any one of the spark plug wires coming from the distributor. This inductive pick up will have a coil of wire with one side going to ground and the other side going to the remote automobile starter unit at the tach input point. This inductive pick up outputs a high voltage pulse every time a spark plug fires.