12 Volt Bay Heater Problem

[wigginsjsr]

YC1, I would be interested in you showing how I could replace the heater and still have the indicator light function when the heater comes on.

[harris155]

If you look at the drawing that YC1 provided you will see that the first indicating lamp is turned on when you arm the system by the ON/OFF switch. The Heater in service indicating light is turned on by the external snap disc thermodisc. You will have to do nothing if you replace the heater with a different one and the instrumentation will still work.

[Dr4Film]

Originally Posted by wigginsjsr

I would be interested in you showing how I could replace the heater and still have the indicator light function when the heater comes on.

I did exactly what you are asking, and it is posted back on #7.

Your wiring harness will have a connector with three wires. One RED, one WHITE and one BLUE.

The Red and White wires are the 12 VDC positive and negative to drive the heater and fan. They are heavy gauge wires. The Blue is the SIGNAL wire coming from the SNAP disc.

If you remove the heater, the SNAP disc still operates and the switch and indicator light will light up when operational.

Read Post #7 to see the type of 12 VDC heater I installed. Since it did NOT have an internal relay like what the Cargo Heater has inside to turn the heater and fan on and off, I had to buy one from NAPA and wire it into the circuit. You can see that in the photos.

The operation is very simple.

When you turn the SYSTEM HEAT switch on, it arms the system but the cargo heater will NOT come on until the set temperature of the SNAP disc is reached. When the SNAP disc closes, it sends a 12 VDC signal to the relay which then causes the relay to close and allows the positive 12 VDC to start the heater and fan.

Your tank pad heaters operate completely separate from the bay heater. If you look at the electrical schematic, you will see that there is a separate relay just for the tank pad heaters. There is no SNAP disc for the tank pad heaters. When the System Heat switch is ON, the tank pad heaters are always on. It is only the Bay Heater that has a temperature control.

Dr4Film ----- Richard

[YC1]

My lips never moved and you have excellent answers.

If you don't mind Richard, I am going to copy and save your very complete answer for future reference. And it will keep me from reinventing the wheel. So if you see it posted again, and you will, I will try to acknowledge that I did indeed steal it.

It would be fun to get a broken heater and find out the suppliers of the parts. This thing could be made much cheaper and way more reliable.

[Dr4Film]

Originally Posted by YC1

If you don't mind Richard, I am going to copy and save your very complete answer for future reference. And it will keep me from reinventing the wheel. So if you see it posted again, and you will, I will try to acknowledge that I did indeed steal it.

It would be fun to get a broken heater and find out the suppliers of the parts. This thing could be made much cheaper and way more reliable.

I don't mind at all. I believe in sharing all that I know and have learned before I leave this earthly place. What good does it do anyone if the knowledge is not shared with others.

Those service bay cargo heaters are WAY too expensive and have been over-engineered. There are numerous 12 VDC heaters in the market to choose from. The one that I am trying is called Road-Pro 180 Watt Dash Heater. If for some reason that one craps out, I will search for another one until I find one that will hold up to the demands.

All that is really needed is the high amp relay to turn the heater/fan on or off depending on the status of the Snap disc, and a good heater too.

Dr4Film ----- Richard

[roscoesdad]

Harbor Frieght has a 12 volt heater that is very economical. 12V Heater w/ Fan I have no info on this heater but it is cheap enough. Would be simple to wire the relay and put ends on the connections so the heater could be pluged into existing wiring.

Amazon has the Road-Pro even cheaper. http://http://www.amazon.com/Roadpro.../dp/B000IXTGHW