So ever since I got my e fans installed and properly fixed to run right.. I’ve started experiencing issues with my battery voltage dropping. I do have a factory 105A alternator running it and the fans positive lines are connected straight to the battery. Also if it helps someone figure out why this is happening my battery is from 2022. But before when I had an issue with the fans not shutting off when the truck was off, the trucks voltage was perfect and didn’t drop. I’m asking because ever since I’ve experienced the voltage drops I’ve been having a slight stutter feeling when I start from red lights using more than half throttle. I replaced spark plugs, plug wires, and coil packs thinking it was a misfire but I never got a code for that. I also replaced my MAF and MAP sensors but still had the stutter. I than upgraded to a 255A alternator but that was overcharging my battery so I took it out and put the factory 105A back in and it did bring my volts back down. If anyone could help me figure out what’s causing this I’d really appreciate it!! Thank you.
Battery voltage issues??
- Thread starter robvilla
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
- Joined
- Feb 23, 2025
- Posts
- 171
- Reaction score
- 116
Sorry to tell you this, but the fans can’t go direct to the battery, that creates a parasitic draw, which will eat your battery. Now you need a new battery and to wire the fans properly. Your other symptoms may well be related to a bad battery.
- Joined
- Aug 2, 2018
- Posts
- 10,270
- Reaction score
- 14,870
Something is going on there for sure. I'm mystified by your statement that the larger alternator was overcharging your battery. If your charging system is working properly, it should not matter what size alternator you run. The charging system should regulate the charging of the battery and not overcharge it.
What year and does it have RVC? (Regulated Voltage Control)
Probably not if the stock alternator is the 105A version.
Probably not if the stock alternator is the 105A version.
swathdiver
Full Access Member
Yeah, might be time for a 160 amp alternator.
Is this an electric fan conversion, having had a clutch fan from the factory? Starting in 2005 most of the OE alternators were 160A. Your 105A one ain't going to cut it for electric fans.
