leathermaneod

Hi everyone,
I am new to this forum and somewhat new to cummins diesels. I recently purchased an 01 cummins with 250,000 miles. I am trying to figure out if a fusible link is necessary between the battery and grid heater Solenoids? When I bought the truck I didn't know how that cable was supposed to be set up And it had two separate cables going to the grid heater relays instead of the stock setup(two cables spliced together at the battery). As it turns out one of the cables had been replaced with a 4 awg premade cable from autozone and the other was spliced and reduced to 12 awg. This didn't seem right to me so I replaced it with another 4 awg premade cable. It looks nice and works great. However, I was reading forums and realized that it is supposed to be a fusible link as an over current protection setup. My question is, how important is the fusible link? Do I need to order a new factory cable for this or am I fine without any over current protection on this?

cougar

Each grid heater draws about 95 amps, and you have 2 of them. So yes, some type of circuit protection is necessary. The FSM calls for a 12 gauge fusible link to each relay. A fusible link is a special wire, DO NOT replace it with regular wire! You can replace a fusible link with an equivalent "slow blow" fuse. Any other type of fuse may not protect the circuit properly and is not recommended.

leathermaneod

Wow thanks for the reply! So I do need to change it. Would a 12 awg fusible link be the 8awg spliced to 12awg fusible link wire then or how is that set up exactly?

cougar

On mine, the fusible link is connected at the battery as it should be, then it connects to a larger standard wire to the relay.

KATOOM

Here's some information you may find useful. Ram Diesel Manifold Heater Problems

leathermaneod

Thanks for the link KATOOM. Based on the schematic on that page would you say the fuse link portion of the cable should be 12 AWG and the main portion 6 AWG? That's what it looks like to me, I'd just like a second opinion in case I end up needing to make this thing myself if the dealer can't get it.

DIESELWRKS

Do ur self. I paid primo at the dealership.

leathermaneod

dieselwrks, do you happen to have the part number for that fusible link? I waited a week trying to get it from the dealer and they got the wrong part. they got the wires that go from relay to grid heater instead of battery to relay. I was going to make it myself but no parts store around me carries 6 awg wire. Everyone is telling me to just get it from an electrical supply store but i don't know if that is as good since its house wiring not auto wiring??? anyway at this rate ill be spending just as much to do it myself as it cost from the dealer.

leathermaneod

ok so I decided to go with a 4 gauge cable to each grid heater relay. Each with a 100 amp fuse inline. Anyone see a problem with that? The reason I'm doing this is because it is extremely hard to find 6 awg cable here in Watertown, NY so I can't replicate the factory setup. Any feedback is greatly appreciated!!