To IS or not to IS
That IS the question
IS there a control board
OR IS there NOT a control board?
Look, the word CONTROL means not-expected operation. Most bi-directional units have a threshold voltage. If this one solenoid switches on and off with the key what are the chances of having a control board fail in that particular mode?
I have seen a lot of rigs where the dual throw rocker switch, momentary one side was neutered and changed to IGNITION B because starter motor current inrush blew the solenoid contacts to East Jesus. When in the opposite position permanent on, the system did nothing, the switch just sat there are grinned at you. Pressed for "Emergency Start" that grin did not change. Not functional.
Control function is supposed to allow the chassis battery achieve 13.2 volts whereupon the SMART solenoid enables both banks in parallel.
Conversely
When the HOUSE batteries achieve 13.2 volts, the solenoid will parallel both banks.
The engine alternator thusly ends up charging both house and chassis batteries
The converter or inverter ends up charging the chassis battery. 99.999% of Mopar ECU voltage regulator problems do not occur within the ECU. They occur at the wire termination of the field to ECU connection. I should know. I own one of the millions of misfits.
Alternator to external voltage regulator harnesses must be constructed near bulletproof and the regulator must not be contained in an ECU located right at the engine battery. MoPar chose to ignore this.
So an overwhelming majority of today's alternators are housed within the alternator to minimize a crappy quality but expensive harness to go bad. Stupidity to cure shoddy construction practices.
But BIRD units do not have to live in a 220F environment. They can be integrated into a tower type ESSEX solenoid. compared to the standard garbage metal solenoid the Essex is like comparing a Rolls Royce to a Ford Pinto.
Potting the entire works except for male faston terminals used for chassis ground makes the potted unit far less trouble prone. For mechanical strength I used 12 gauge wire, solder and glob of grease to make the chassis negative wire less vulnerable.
I then mounted that six dollar Ford starter solenoid above or below the Bi-Directional relay, and THAT wire ran to the dash switch.
I must have installed 40-50 units this way (Armando learned how to do this right and I supervised) and after insisting the 200-amp separator be used, I NEVER had one comeback in what? Ten? Eleven years? There is no strain on solenoids if they are not overtaxed for engine starting duty. Use the right component for the right job. An 800 ampere rated Ford solenoid can withstand tantrums from the most dysfunctional malfunctioning starter motor.
Yes, a person "could" reharness a functioning remote control type BIRD then use Essex type tower solenoid(s) and achieve a decent setup. But laying in a good length of critical grade chassis harness is not inexpensive nor quick. It involves using cross link XT wire, soldered connections and stout protection like nylon cable spiral wrap. And Adel type clamps to secure the entire harness to chassis tie points.
Why bother with all that when there are good units out there like the Blue Seas and Sure Power integrated sealed units? Even a cheapo online Ford starter solenoid works great for emergency jump starts but I would grind off the cad plating around one mounting hole and SOLDER the necessary ground wire running from the Ford solenoid mounting bracket through a quarter inch ring terminal, to a 12 gauge wire (again for mechanical strength then to a secure frame ground. Then a glop of chassis grease was slopped over the frame connection.
Silicone grease was applied to all exposed terminals, especially fast-on type. Terminals were tweaked to very firm push on effort then strain relieved with an adel clamp.
Do it once, do it right and go on to bigger and better things. To bad this cannot be done with converters and cranky electro-chemical sensitive batteries.
By connecting
