I don't know about "correct", but the use of a cube relay over a Ford relay
will be a better solution to overcome the
actual deficiency that causes the clickies. Over time, the purple wire circuit develops resistance that causes a voltage drop to the point that the circuit can't carry sufficient current to pull-in the solenoid.
There are three components to Ohms Law in play here. Resistance, Voltage, and Current. Voltage will be a nominal 12V, but the lower it is, the higher the current. Resistance is also basically constant. The fact the circuit's resistance has
increased over time is why the clickies develop. Amps is the amount of "work" required. The lower the Amp draw, the "better" the cure.
I went out and measured the resistance of the Ford solenoid in my Super Duty. The coil is 2.4 Ohms. A cube relay on my shelf measures 88 Ohms.
Using an
Ohms Law Calculator The Ford solenoid requires 5 Amps @ 12 V to "pull in". The cube relay requires .136 Amp to pull in.
5 Amps is a heck of lot more energy than 136 Milliamps. The idea of the purple wire mods is to minimize the 'amount' of energy needed to be passed through the circuit to 'pull in' the coil. The cube relay requires ~1/50th the amount of energy the Ford solenoid does. This is what makes the cube relay a 'better' solution than the Ford relay.
A cube relay draws 1/50th the current through the purple wire that the Ford solenoid does.
I had a thought on this too. I've owned several non-SyTy S-series, and I've never had to install a clickies relay in any of them. 2 of these truck have gone over 300K miles. So why do SyTy develop this malady, and regular S-series never do? Here's my thoughts:
A: There's an additional ~10 feet of wire in the SyTy because of the floor shifter and Neutral switch location. This adds resistance.
B: Regular S-Series
don't have a P/N safety switch. This P/N function is achieved with mechanical lockout depending on column shifter position.
The switch becomes increasingly more resistive with time in service.
C: Battery cable length. Because of the SyTy turbo and exhaust configuration, the battery cables are both almost 3X as long as they are in a regular S-series. This extra length increases resistance.
The key take-away is that there is a point where there's too much resistance in the purple wire circuit to pass the needed current (amps) to energize the solenoid coil. This resistance increases as the truck ages. When it reaches the magic point, clickies result. Reducing the amount of energy required, is what solves the clckies. The relay over the Ford Solenoid is
50 times more effective at achieving the desired result: No more clickies.
But both methods "work".
:2cents:
DaveP
