Manifold Heater connections

[JKellis]

I was doing my annual battery terminal cleaning today. On the driver side positive terminal there is the main cable to the starter, the cable to the passenger side battery, the cable to the fuse block, and the two wires to the manifold heater relay. I was wondering if it would cause any problems if I moved the manifold heater wires to the other end of the cable to the fuse block and attach them there? It would make the battery connections easier to maintain. The short cable to the fuse block appears to be more than large enough to handle the amp load of the grid heaters.

 

[Ozymandias]

I wouldn't do that, the gridheater pulls down the voltage a lot, if you connect that to the fuseboxes inlet you'll pull down the whole cars electric/electronics.
On the Gen3 it is exactly the same setup, the ECM and everything else runs from the left battery, the gridheater runs solely from the right battery.

 

[JKellis]

Yea, when my grid heater cycles on while the truck is warming up in the driveway, my voltage drops to around 11 volts, the headlights dim, rpms drop about 100, even the fuel pressure drops about 2 psi. As soon as it cycles off, everything returns to normal. I just thought since everything running off the fuse/relay box is seeing the voltage drop anyway, it wouldn't make much difference.