I worked all afternoon and evening putting in a Kim Hotstart heater in the #1 truck. It’s going to be a cold week. I need a better heater. I was nearly done tonight with the swap and found that there is a 5/8″ heater hose that has to fit on a 3/8″ barb. There was a smaller piece of hose adapting the two together, but I nicked it with the knife as I was removing it. The stores were closed by the time I figured this out. So the truck is not going to drive me to work in the morning.

The coolant bottle also had to be rotated 180 degrees because it would be in the way of the air conditioning hose that goes around the firewall, when I add the AC that is. So a couple more holes had to be drilled.

Hopefully the Kim Hotstart heater will have decent longevity. It’s a 240vac 1500w heater running at 300-400vdc. That’s about 2700w. At least the plastic body helps get rid of ground fault potential.

Here is the Hotstart heater before it has one of the mounting tabs shortened. Next to it is the wiring that I add to make it easy to test and remove if needed. The small connectors at the end of each of the wires are from the Hotstart. The high voltage connector with the green and blue 10ga wires, has 4 positions with two of them empty between the pins to help prevent arc-over. The 3 position connector with the 2 yellow wires is for the temperature sensor. The pump motor shown in other images, has a 2 pin connector. This keeps connectors from being confused during reassembly.Hotstart Heater.

This #1 truck was built very late in the program. 1996. So it has some improvements. Tonight I found that the hoses attached to the pump and the heater had a large diameter stainless spring inside to keep the hoses from collapsing. This could be helpful.[/caption]

The Z shaped hose that connects the pump to the heater, tends to kink at both ends. These stainless springs took care of that. I should retrofit the #2 truck with the same hose springs.

As soon as I can adapt the 5/8″ hose to the 3/8″ barb, the truck will be ready. I also pre-primed the pump by adding coolant to the heater and the pump with a syringe, then spinning the pump before it will be put back into the truck.

I was not able to test the original heater output before the swap, to generate a temperature versus time plot.