Liberator221,

Surprisingly, I've got what appears to be a #4 hot and ground wire running to the helm in my boat. It's an '02, so maybe they got with that at some point prior. It is a bit unnerving to have a hot 12v buss bar completely exposed as it is, even if it is under the dash, relatively protected. I feel better having covered it with a couple layers of duct tape. They do daisy chain the 12v and grounds for all the switches and gauges and such, and it does look like the hatch lift is, indeed, powered from the dash. I'm not so concerned about that as I am the voltage drop from the bilge blowers. To be honest, I don't think I've ever looked at the voltage gage while running the hatch up or down. Will have to do that, as well. It just seems odd that such a small draw (blowers) drops the gage that much, given everything else that is drawing on the system as well. It's really the fact that I don't recall it being that much of a drop on the voltage gauge, if any, prior to the rebuild. That's what really got my attention. I think separating the power for them from the dash via relay will ease my concern here, but it won't alleviate an actual problem if there is one.

Part of my concern also stems from the fact that we are now charging both batteries at the same time (assuming the ACR is functioning as prescribed), whereas, prior, we were only charging one at a time, and that this may be why I'm not seeing the voltage I think I should. Is this not of relevant? Nobody has addressed this specific point.

Thanks. Brad.

The pump in question is a used older version, correct? May be time for a rebuild. One of mine failed. Before it failed it was considerably different sounding than the other one. Weldon dude told me that even though it is a "marine" pump, the body (top cap and screws) are not watertight or even have a seal. WTH? Said he recommends it be sealed when I get it back. Apparently, they can get moisture inside and have no way to drain out the water and rust up. Mine is mounted up high enough where there is no way in hell it would get that wet unless the boat sank or you sprayed it with a garden hose all the time. When Weldon inspected mine yep it was full of rust which was the cause of failure in my case. Looked perfect from the outside too. So ya, there is that which may explain your excessive noise. Don't think it should be as loud as you say over the exhaust.

I`ve never heard of, even on the holley tech forums, an ECU "dumping" the tune if the battery is low.
Neither was it ever mentioned at the Holley class I took.

I had a switch at the dash that would actuate a relay and combine both batteries. Came that way from cig. Helps with starting and full voltage. or switch to "all" when starting.

Hook this up to the battery directly and youll get a read out and charging ports, I use these a lot.

There`s always a diferent reading at the dash , mine will be 11v even thou the batteries are at 13.5v .

I had the A-1000`s pumps and they are loud.
Holley pumps were pretty quiet .

Whomever told you that is speading misinformation , must be a democrat..


There is no direct evidence from the provided references or general knowledge that a Holley HP ECU will automatically delete its tune due to a low battery. However, a low battery can cause issues with the ECU's operation, which might be mistaken for a tune being deleted. Here’s a breakdown based on available information and reasoning:

1. ECU Behavior with Low Battery Voltage:
   • A low battery voltage can cause the Holley HP ECU to malfunction, as it requires a stable power supply (recommended to be connected directly to the battery terminals) to function properly.corvetteforum.com
   • Issues such as the ECU not syncing, failing to recognize sensors, or shutting down during operation have been reported when power supply issues occur, as seen in a case where an ECU became unresponsive and would not sync with a computer. These issues could be misinterpreted as a tune being "deleted," but they are more likely related to power supply disruptions rather than the tune itself being erased.offshoreonly.com
   • The Holley HP ECU has non-volatile memory, meaning the tune is stored in a way that does not require constant power to retain the data. A low battery would not typically erase the tune unless there was a catastrophic failure or corruption of the ECU’s firmware, which is not explicitly documented in the provided references.
2. Related Issues from User Reports:
   • In one instance, a user reported their Holley HP EFI setup shutting down and failing to restart, with symptoms like no fuel pump power and a crank-no-start condition. They noted that the ECU was still communicating with a laptop (indicating the tune was likely still intact), but the system wasn’t functioning due to potential power or ground issues. This suggests that low voltage or poor connections could disrupt operation without necessarily deleting the tune.forums.holley.com
   • Another user reported the ECU becoming "totally blank" and unresponsive, but this was attributed to a potential hardware failure (e.g., a bad chip or connection) rather than a low battery explicitly causing a tune deletion.offshoreonly.com
3. Holley’s Recommendations and Safeguards:
   • Holley emphasizes the importance of connecting the ECU directly to the battery to ensure a clean and stable power source, as the battery acts as a voltage filter. A low battery could introduce electrical noise or insufficient voltage, potentially causing erratic behavior, but not necessarily tune deletion.corvetteforum.com
   • The Holley HP ECU includes features like internal data logging with 2GB of memory, which is non-volatile and retains data without power. This further supports the idea that a tune would not be deleted due to low battery voltage alone.summitracing.com
4. Possible Misinterpretations:
   • If a low battery causes the ECU to reset or fail to boot properly, it might appear to a user that the tune has been "deleted" because the system isn’t functioning as expected. In reality, the tune is likely still stored but inaccessible due to power-related issues.
   • Firmware corruption or a failed update could potentially lead to a loss of tune data, but this would require specific conditions (e.g., interrupted firmware update) and is not directly linked to a low battery.offshoreonly.com

Conclusion: There is no conclusive evidence that a low battery will cause a Holley HP ECU to delete its tune. However, a low battery can lead to operational issues, such as the ECU failing to function properly, which might mimic symptoms of a lost tune. To avoid problems, ensure the ECU is connected directly to a healthy battery, as recommended by Holley, and check all power and ground connections if issues arise. If you suspect a tune has been lost, it’s more likely a symptom of a power issue or ECU malfunction rather than an automatic deletion caused by low voltage. For further diagnosis, connecting the ECU to a laptop to verify the tune’s presence or consulting a Holley EFI dealer for support is recommen

Good to know they address the power concerns on the newer models.
Just a suggestion; make two temporary jumper wires. Disconnect volt gauge and connect jumpers from buss bats to gauge. Run boat at idle and 2000 with blowers on to see if readings change. You’ll know if you have a problem or just bad reading.

Dan,

Don't think he's a Democrat. He's into way too many things that Democrats hate.

I'm just passing along what I've been told by someone that deals with Holley ECMs on a daily basis. Literally. He does a full tune at least once a week. If he tells me he's seen it happen, I'm inclined to believe him. I didn't ask him what that voltage was. Hell... It might be something pretty crazy low. He also indicated it had only happened because someone had tried starting the engine while the batteries were already really low. If I had to guess, I'd say it didn't "dump" the tune, but rather the file had gotten corrupted. I know I had thumb drive lose files this way when power went out and I had it plugged into a computer. Flash memory is vulnerable to power flutter. Besides, He wasn't trying to scare me. I had my concerns about it, and his intention was to reassure me it wasn't something I'd need to worry about. It is just something that has been in the back of my mind since noticing the low voltage readings. My antennae are getting sore from trying to stay aware of everything that could go wrong with this engine after the rebuild.

It's all good. I think DiamondDave can rest easy on this topic.

Good to know on the A1000's. That's what the builder was recommending when we were in the process of the rebuild. Tuner tells me the difference between loud and quiet is "gear pump" and "turbine pump". My Weldon is a gear pump. I thought the Aeromotive was a turbine? Yes/no? Genuinely don't know.

I don't see a volt readout on the USB port widgets you posted. ???

Thanks. Brad.

Liberator221,

"Buss batts"...? You mean from the battery to the gauge?

Thanks. Brad.

Buss bars sorry. Your #4 power and ground feeds you said we’re at the helm from the rear.
other than these little gremlins are you happy with the report/rebuild?

I’m thinking your ok just bad readings on gauge but I know the thought of dead battery in middle of Cumberland isn’t good

Liberator221,

Wouldn't that give pretty much the same reading, unless you're just trying to jumper past the wire already going from the buss to the gauge?

Overall? Yes, in the fact that I've got my boat back and the piston failure didn't cost any real boating time (the weather has sucked up until the last month or so). I'm down on power, when I really thought we'd be up by a good bit. Increased valve lift by .030", roller rockers, modified intake, removing plenum for better airflow and a smaller blower wheel. All signs indicated we'd be up in power and I'd be looking for a 30P prop to crack that 80MPH mark. But we're barely cracking the 70 mark, as I'm about 2500RPM off pace. Tuner says it's because the original build, with the ProCharger, didn't pull the timing like it should have (ProCharger doesn't address the ECM at all). We were running NA timing at ~3lbs of boost (most likely the leading factor in the failure), and now we're at a conservative boost timing at WOT. I think there's some room for improvement, and the tuner is willing to play with it, but he's a little apprehensive, given the stock iron heads. A couple of individuals in the know have told me we could go 3-4° more advance and recover most of what's missing pretty safely. We are going to try and get back together after this weekend, a handful of new plugs in hand, and work on it.

Thanks. Brad.