[Guy]

We went from summer to fall in one day here. On my list of to do's for winter is to investigate why the block heater is drawing more than 20 amps, when it used to draw 10. With age do they degrade and have more resistance? It had been tripping the inverter ckt it is on, so I plugged it directly in to shore power, and it cooked my 15 amp 12 gauge ext cord after 60 minutes. I can't see where it enters the block, but it is in the passenger side lower block area. I think I am going to have to get greasy on this one!

[Fulltiming]

Likely the block heater will have to be replaced. Keep it turned off until you can replace it. It could be the wiring but is most likely the block heater element itself.

[77newell]

On the 84 vintage block in my 77 coach the heater was low on the passenger side of the block towards the rear as the engine sits in the coach. Given the additional amps it is drawing, the heater element is the only possible cause since the wiring would go up in flames absorbing that much power.

One caution I was told by my DD dealer was to be sure the power to the heater is shut off prior to starting the engine. At start, the are times when a big slug of air gets pumped through the engine and if the power is on there is nowhere for the heat to go and it toasts the element.

[Guy]

Thanks guys ! I am going to get on it. After all , ' How hard can it be ?"

[bestgenman]

It’s likely to be a KIM hotstart unit.  They do have a screw-in element but are difficult to remove because both threads are aluminum.  The wiring can also be suspect as the insulation suffers from the heat.  It might be easier to drop the coolant and do repairs or replace.

[Guy]

Thanks Gordon. I will be stationary for winter for 16 weeks in California. I will put on my big boy pants and do it then. I don't want to have an issue putting things back together while on the road. I believe you are correct about the unit being a KIM. In addition to that, I can see that a previous owner has two 120 v cords tie into one cord and terminate into one 120 v 15 amp plug. I may find I have two jerry rigged block heaters.

[Richard]

Guy, not to add to the list......
But if you are draining the coolant, it might be the right time to evaluate the age of the coolant and the condition of all the hoses.

Just sayin.

[Guy]

Yes I agree 100 percent.  I have 20 gallons of the replacement coolant in the enclosed trailer which always follows us. I am debating should I replace the existing coolant- water mix before I put on 3k miles going west for the winter, and do all the related work at one time?  Or should I change it now, and then recover it when I do the other work over the winter 

Things to consider are I know the coolant has been diluted by me with 7 gallons of distilled water over the past years. I  think I will escape any freezing temps. I am paranoid of engine cooling system damage. Btw, I am changing out the unknown green coolant that the Detroit Dealer put in. When I contacted them,they were not sure what was put in at the time of rebuild. I am putting in the Peak Final Charge pre-diluted extended life coolant, unless a guru tells me not to

I head west  Wednesday, so no more procrastinating for me ......

[HoosierDaddy]

I would get some coolant test strips and if it checks ok I’d run it until I was ready to change the heater and hoses etc.

[Richard]

What Dean said.......