Power cuts out when cranking

[ssenay72]

Did the painless 20114 harness, terminator x and Dakota digital over the winter. Everything works and today i tried to start the car (first time since the changes) and the motor turns over just fine, but the power cuts out everywhere else and the gauges and terminator x reboots (looks like total power loss when cranking). Battery is new and on a charger all the time.

Any ideas?

 

[73Z L92]

Haven't done the Holley stuff but a number of LS swaps. You need 12 volts in start and run. You may have 12 volts to the starter but not anywhere else when cranking. I've used the Painless wiring harness on a few swaps. I'm sure there is a wire that has 12 volts in start and run. Maybe more than one.

 

[ssenay72]

It has more than 12. It’s not a Holley issue. Something in the wiring I think. Everything loses power. But the motor keeps turning over

 

[grzewnicki]

What 73Z L92 is saying is: Certain circuits are not energized when the key is turned to crank, heck even modern cars you see that the radio and the gauges temporarily lose power during crank. It is designed this way to provide the most power to the starter and ignition system during cranking. I had the same issue with my Sniper system, the Sniper display would go blank during cranking and it would not start. I rewired the power wire to a circuit that was still energized with key in crank position. What color wire are you using in the Painless harness to provide power to your terminator? If you having a hard time understanding, look at this diagram: underdash wiring. Top right hand corner is the ign switch, the legend next to it tells you what happens when turning sw to start, run, and acc. During start grd 1 and 2 are grounded and ign1 bat 1 and SOL are connected. In run the following connections are made: Ign 1 & Bat 1 / Acc & Bat2 and Ign and Bat 3. So you see the common terminal that is hot in both start and run is IGN 1, which is a pink wire coming out of ign switch and going to fuse block: I followed the pink wire on this wiring diagram Fuse block diagram. It goes into the fuse block on the left side to terminal 39, if you follow the curvy line (which represents a 10A fuse) down to bottom left of fuse block you can see where it is connected to terminal 3 and comes back out bottom left of fuse block as a pink and black wire. Also the IGN spade terminal on the fuse block is powered by the pink wire. SO you can run a wire to that terminal and power your Terminator (which is exactly what I did). Did you have the terminator system working with your old harness?

 

[ssenay72]

I have a painless fuse box. I’m going to have to run a test on the accessory ports to see if they are clean when cranking. I had a feeling that could be it.

 

[ssenay72]

New install of terminator and painless at the same time, my old stock fuse box was working with my sniper system. I can’t remember how that was wire.

i have the red/white wire in one of the switch acc ports on the fuse box. I watched the ecu as i cranked and it goes dead so thats the issue. Ill have to find a hot/crank port to use.

 

[grzewnicki]

Just move that wire from the acc port on fuse block to ign port and that should work.

 

[Twisted_Metal]

You need an ignition source of power rather than an accessory source.
Accessories go dead during cranking.

 

[ssenay72]

Problem is painless doesn’t label them ign. Just acc and batt. Fuse tap might be easier at this point

 

[grzewnicki]

I know on my stock harness I have an un-used pink and black wire sort of behind the ashtray, just ends with a plastic connector covering the terminal. No idea what "option" it was there for originally. Even my M & H replacement harness has it. If your painless harness has that same thing you could connect there.