wont run while engine on

**cybermob2** · 04-26-2004, 09:40 PM

got all my stuff installed. did all my testing, everything works great.

using pw70a w/relay setup (no ITPS)

problem is, it will remain on through starting the engine, but w/in 5 seconds it shuts down and will not restart (i guess thats a brownout)

what gives?

**god_of_cpu** · 04-26-2004, 10:12 PM

What does your voltage read on the lines for power? When engine is off and when on.

**cybermob2** · 04-26-2004, 10:39 PM

engine off, ACC on = 12V

engine on = 14.5V

cranking = 9.5V

**cybermob2** · 04-26-2004, 10:41 PM

specs on ituner say 12Vin = 12 +/- 15%

is that right?

that would be the problem then, cause that would mean it accepts 10.2V - 13.8V.

**god_of_cpu** · 04-26-2004, 10:54 PM

Can you turn it on manually after the car is on and the voltage is at 14.5v? If you can then you probably just need a tank circuit that will keep the voltage up during crank. If it still doesn't work after the car has been started for a while it's got to be that 14.5v is just too much for it, you'll have to put a voltage regulator before it, theres been a bunch of other posts on here on voltage regulation.

Also, make sure your running your power line directly to the battery with at least 10 guage or better wire.

**cybermob2** · 04-26-2004, 11:25 PM

it will NOT turn back on after it shuts off.

i'm running 10ga wire, less than 12' of it.

i haven't finished soldering the wires yet (they are just twisted) but i dont consider that a defining factor in the problem.

about the regulation, i'm going to try running the PSU off a laptop adapter w/12Vout. see if it makes a difference.

like i say, it stays on during crank. basically wont start or run while the engine is on.

**wizardPC** · 04-27-2004, 12:05 AM

I had that exact same problem
14.5V = No Go for pw120?

never solved it. I ended up buying a morex case w/ power supply

**cybermob2** · 04-27-2004, 11:17 PM

i ran my battery dead today (oops). turns out with the computer running and the stereo cranked i only get about 10min.

anyways... after i charged it partially, the computer started to run while the engine was on! however, about 5 min on the highway it restarted, then 3 min later shutdown.

i'm guessing the running voltage was lower cause of the mostly drained battery, but as the alternator charged it, it got closer to full.

i'm going to try a laptop dc adapter w/12Vout in before the pw70 and see if it is better.