another stupid issue... truck floods out when I turn on a light

Ok, so ive been was having a problem where my truck would flood if it sat idleing too long. recently it started flooding out when I turned on the head lights or even the dome light. the alternator is charging at 14v and I'm getting 13.3 on the back side of my isolator (dual battery setup). this system has been inplace and working for 3 years. both batteries test good and fully charged. I'm going to look for a loose ground tonight. I always thought it was funny that it would run a bit rich at night. could this be an issue with the injector latency settings even though I haven't messed with them other than copying the ones from the vehicle I got the injectors from? anyone have any ideas if it isn't a grounding problem?

Could be? Kind of a weird issue? Latency is usually fairly flat around 13 to 14 volts. $0D does have battery voltage and fuel pump voltage IIRC to watch in data log. Pump ground could be an issue.

Make sure scantool voltage reading is close to accurate. If it's only seeing 10-12V when the injectors are seeing 13+ there could be problems.

I took all the main grounds loose and cleaned them. none of them really jumped out at me as not making a good connection, but I didn't have a problem last night so keeping my fingers crossed. I need to nip these stupid issues in the bud by Wed. before I get it on the dyno. renting by the hour gets too expensive to be chasing stupid stuff around insted of what you originally came to do.

this is starting to get annoying. worked fine for a week. now its doing it again but not all the time... the only thing I can think of is my main battery has steel tips insted of copper, maybe the one at the frame end is rusting between it and the frame. thoughts anyone.

Alternator! My sons Toyota truck would run fine then have a dead battery, charge it, load test, charging system test, fine! Few days later same thing... finally we were watching charging system and turned everything on and it was charging, then stopped!

You could data log and watch for voltage issue?

looking at the logs voltage never drops below 13. I'll look to see if i have another alternator I can toss on there and see if there is a difference.

If you never see a drop in voltage it's probably not the altenator... since it seems to be at night with lights on maybe do a data log at night with lights on only, let it idle and see if voltage is changing?

Alos look for going open loop when this is happening?

Then back to those battery cables, connections, grounds...

I'll start with the the stuff I can do first. I'm going to toss my maintenace charger in the truck and let it sit on the battery for a few days until I get time to put the TB back on it.