Sniper efi wiring to RF stock harness

[Brave Salmon]

My Sniper system has been replaced because I was having issues getting it stable. One lingering issue is that the snipers pink wire needs to be connected to a +12vdc wire that remains hot while cranking. They call this switched ignition. I have used the tan electric choke lead from the standard Ron Francis harness. The choke line stays hot while cranking perfectly. However, the handheld device reboots itself frequently while cranking the motor. This prevents me from getting an accurate log showing the entire startup. Anyone have any idea why this is happening? I have rechecked the wiring and it is intact. Test lite shows that the wire stays hot while cranking but the handheld reboots. Help please.

[JOP33]

Check your handheld wire connection to make sure it is snug and not vibrating loose. Check to make sure you have no areas for potential shorts in that connection either. I have mine wire the same way and have had no issues with it rebooting.

[Brave Salmon]

Thanks for the input. I had the entire unit swapped out under warranty. I just finished the re-install when I discovered this problem still existed. Holley support is non existent so I am at a loss. I plan to replace the original harness assy tomorrow and see if that changes anything. That will be the last piece of the entire Sniper system. That choke lead stays hot in crank and run. I checked it at the 7 pin connector and it stays hot there. From the 7 pin, it goes directly to the ecu in the Sniper. Damned thing has me rethinking everything I know about wiring.

[MonstaS4]

You need to check the voltage with a multimeter on the choke wire while it's cranking. My guess is the voltage is dropping below ~9v while cranking which is causing the Sniper to reboot.

Either your battery charge is low/faulty cell or there is too much volatge drop from the battery to the RF harness. Checking the voltage at the battery while cranking will tell you which is the problem.

[Brave Salmon]

MonstaS4-Thabnks for the idea. I checked it and the voltage at the pink wire dropped to 8.2vdc while cranking. I have the charger on the battery overnight and I will try again tomorrow. I'm kind of surprised to see such a low voltage since the motor cranks really well but what the heck. thanks again. Ill update tomorrow

[TxMike64]

Try connecting to the starter solenoid instead of the choke.
132764

[Brave Salmon]

Try connecting to the starter solenoid instead of the choke.
132764

Hi Mike, thanks for your suggestion. In my case, I am using a different solenoid entirely. The choke lead is the perfect point to connect the switched ignition wire since it remains hot while the motor cranks and while in the run position.

[Brave Salmon]

Ok, 10 points to the MONSTA64 wizard. Last nite I checked voltage at the fuel pump relay where the pink wire goes and it was reading 8.2vdc while cranking the motor. I put the charger on the battery overnight and checked it this morning. The voltage while cranking was 11.6vdc and the handheld did not reboot. I'm guessing that the ECU which drives the handheld shut down for that short time the voltage is low and when the key is released, the ecu fires up and restarts the handheld. In order to do a good log of the startup process for the Sniper, you need to turn on the key and start logging before you start the motor. It is apparent that you MUST have a fully charged battery in order to do this log process correctly. Thanks to all who chimed in for saving a few of my gray hairs...
NOTE to Johnny McD at Blue Print Engines: Thank you for your excellent support.

[MonstaS4]

Good news Brave Salmon! I have an electrical background which comes in handy at times.

[House Money]

My RF harness - 35 truck but pretty sure they are the same - has a EFI crank wire, I was thinking I would use that wire when I get to that point. I'm using the GM LS3 crate not the Sniper.

Gary

[MonstaS4]

I'm also using an LS3 House Money. I don't think the EFI crank wire is suitable - it's only powered when the starter is active. The GM loom needs an ignition switched signal. I connected the pink wire from the GM loom to the RF loom orange wire labelled 'EFI or Coil'. I had it running a few weekends ago so can confirm this works.

[House Money]

I'm also using an LS3 House Money. I don't think the EFI crank wire is suitable - it's only powered when the starter is active. The GM loom needs an ignition switched signal. I connected the pink wire from the GM loom to the RF loom orange wire labelled 'EFI or Coil'. I had it running a few weekends ago so can confirm this works.

Thanks for that info!!

[wrp]

I am wondering what effect the 11 volts has. I start getting an alarm at 12.5

134241134242

[Brave Salmon]

If you only have 12.5 volts reading on the handheld and your cts reads 183 I assume you've been running for a while, correct. That leads me to the alternator. Some one wire alternators, like mine, will not switch on until they hit 12-1500 rpm. If you have the one wire setup, give the motor a quick shot of throttle and see if you get the 14 or so volts you should be seeing. If not, get you charging system checked out because 12.5 will NOT charge your battery and you will find yourself on the side of the road before long. please send an update when you figure it out.