How do you run a 115vac heater off a 12vdc battery?

 

One is for the cigarette lighter and the other is for burning out the trip computer.

 

To funny buick!!!!!

Lets not forget we are talking DC NOT AC!!!!

 

Ummmmmm, big inverters?

Yea, I didn't THINK so! ;-)))

Pop

 

They are not 115v AC, they are 115v DC. And the 'ramp up' of voltage is done with a voltage regulator usually containing a zenor diode and voltage divider resistors, it is possible to run the voltage up to hundreds and even thousands of volts from a 12v source, with a coresponding drop in the amperage as the volts increase.

 

The glow plugs are 115v heaters running on a 12v system.

Anyone with a Chiltons, Haynes or Ford service book can look that up for you.

 

And what "module" on our trucks is responsible for doing this trick?

The only 115 volt heating element on our trucks is the block heater.

Pop

 

Partially correct. Oil pressure does drive the fuel injector via the IDM (Injector Driver Module) which sends a 110 volt pulse-width modulated signal to the injector solenoid. 110volts is made available to the IDM via step up transformer (for lack of a better term). All transformers take volts to create amps or vice versa. In this case, we have 12volts at the battery yet need 110 volts at the IDM. Assuming the IDM needs about 6 amps to operate the solenoids.....the battery needs about 550 amps to fire the injectors plus whatever is needed to turn over the starter.

I am just guessing about the amps the IDM require. All I know is when my batteries went bad.....my engine cranked and cranked like nobody's business, just like a gas engine would if the spark plugs were removed. So I know the compression isn't all that hard on the starter, the engine did not fire because there was no fuel getting in the cylinders because there was not sufficient voltage to operate the injectors. Connect up a jump start, and the truck fired right over....no black smoke, no excess fuel out the tail pipe. If the injectors were operating, there would have been a major cloud coming out my tail pipe when the engine finally started.

 

The 115v AC heating element does not use the vehicles DC system, it uses your house wiring.

The 115v DC is provided by a voltage regulator.

 

Yup. The block heater is run from shore power. But the fact still remains that the only heating element on our trucks that is 115 volts is the block heater. The glow plugs are 12 volts. Incidentally, the block heater COULD be powered by 115 volts DC just as well, as it is strictly a resistive load.

And that "voltage regulator" would be located where?

Pop

 

Am I just guessing, or are some folks "just guessing" here?

Pop

 

[QUOTE=gchavez]Partially correct. Oil pressure does drive the fuel injector via the IDM (Injector Driver Module) which sends a 110 volt pulse-width modulated signal to the injector solenoid. 110volts is made available to the IDM via step up transformer (for lack of a better term). All transformers take volts to create amps or vice versa. In this case, we have 12volts at the battery yet need 110 volts at the IDM. Assuming the IDM needs about 6 amps to operate the solenoids.....the battery needs about 550 amps to fire the injectors plus whatever is needed to turn over the starter.
QUOTE]

We have a little bit better conversion than that, because it is 110-115v DC, less amps lost in the conversion. But essentially you are correct, I'm sorry if it sounded like I meant the injectors were negligable, they do have a draw, but then we also use electricity for fuel pump and when you start to add all that up... it adds up to the same thing, we need 2 batteries!

 

I looked it up myself in my Ford Factory service manual. The Glow plug system on the Powerstroke diesel is entirely 12 volts. There is no voltage regulator, no diodes, no resistors. Only the batterys, the relay and the powertrain control module, except for california trucks and Excursions, which emply a glow plug control module....wich is also a 12 volt system.

 

Like I said..... guessin'.

Pop

 

I'll scan and post the info when I get a chance.