Boosting voltage for alternatorless ecomodders

[Daox]

Okay... so this was a total failure haha. I got the dc-dc converter installed tonight. However, I really just didn't think this through. I cut the wires right in front of the ignition coil... but those don't carry a constant 12V. The ECU fires the ignition signal to them as needed. Well, the dc-dc converter just won't work under those conditions. It needs constant 12V. The engine wouldn't even fire up with the dc-dc in the circuit. Looks like I'll have to boost the voltage to the ECU if I want to do this. That probably means I'll need a higher rated dc-dc to fully supply the power the ECU needs. I'll look into that.

So, it sits like this with some electrical tape around it. I'll solder it back up and get some shrink warp on it later on.




However, I still have this dc-dc converter and I have another just like it laying around. They're rated for 80W, and I think they'd probably do a good job running power to the headlights. So, I think I'll use them there instead.

[Gasoline Fumes]

I think the positive feed to the coil is constant with the ignition on, you should be able to boost that.

[Daox]

Perhaps that is it. I just put my voltmeter on the two terminals and got nada with the ignition on. I figured there is a mosfet in the ECU that fires the 12V signal. I can't imagine there being something on the other side of the coil where you'd have to deal with the 40,000V.

[2000mc]

have you checked that your headlights are getting the voltage you do have? Do you know what the voltage drops are to your lights? In effect I boosted my headlight voltage by about a volt by adding relays to the ground/control side of the circuit.

[oil pan 4]

Yes, the OEMs will run 10 amps through 10 feet of 14 gauge wire for your head lights and you will get some voltage drop.
Running a fused wire straight off the battery or alt and slaving the old wiring to run a relay will brighten them up a lot.
(not a problem if you have LEDs)