Carrier ignition electrics

[Pedr]

It is critical with 6 volt system running original Ford coils that there is an ignition resistor in circuit, as the original coils are 4.2 VOLTS, failure to install one or maintain it as servicable will ensure that the coil will overheat and leak, ergo...dead coil.

Daryl, am currently at work and don't have manuals on hand, will check tonight the status of the wiring to the inspection lamp point. The previous owner may, as you have suggested created a hotwire system utilizing the switch, but other than that, I can see no reason for that switch to be in circuit. However is it "constant live", that is to say, doesn't require the ignition to be live to use the lamp. ( this is merely speculation on my part, without suitable documentation to support the theory )

Perhaps one of my learned brethren could offer some pearls of wisdom....Tony?, Rick? Others

Regards,

Pedr

[Big D]

Gidday folks,

Thanks for the replies.

cletrac - yes, I am not familiar with the resistors at all so couldn't say for sure whether this is the right type. The voltage does appear to be stepped down correctly but it is how it is being done that has me curious.

Pedr - I have looked over the circuit diagram in the workshop manual and I don't see any link as such between the inspection lamp and the resistor. I will check the voltage across the inspection lamp switch with the igntion off and see what that is. That might help to narrow down what is going on. I'd be interested in what you thought though after looking at the circuit diagram.

Cheers.
Darryl

[Mike K]

Hi Darryl

That looks like one of my wiring jobs .

As Pedr said .. you do need a resistor with those 4 volt coils .. the system was prone to faults as Ford thermselves woke up changed it to a seperate coil setup.

The divers bell coil will gain some radiant heat from the motor block and radiator , stuck down there .. not a good idea.

The value of that resistor is critical ... the wire in the resistor has to be special wire .. like the wire used in electric heating elements, its made with tungsten or something. You can make up your own resistor by unwinding the element from an old electric heater, but you cannot solder it.

I agree with David, that resistor looks like a 12V off the shelf one .. its value will be too high. A good idea is: you can buy another resisitor of the same type and solder it across that one( parallel), that will half the total ohms and double your voltage at the coil, and double the wattage rating too. . You want the resistor to be stable..not change its ohms value with heat , which is what ordinary wire does.

Mike

[Lynn Eades]

It seems to me the resistor is wrong, and when you turn on your light, the power is going via the circuit to your coil. The bulb is acting as the resistance in your circuit, which just so happens to give 4.2 volts to the coil.

[Rob Beale]

is wound as a small coil about 1 inch long and 3/16 inch dia. It acts as an inductor to stop the current to the coil collapsing when the heavy load of the starter is engaged.

reading the other posts, leads me to believe the extra wire is to provide an alternative current path, as Lynn describes. ie It seems to be taking current FROM the switch TO the coil side of the resistor.

If all else fails, I would disconnect all accessories and leave the ignition, charging and starting circuits intact, then check through them as you have been doing.

Ajays in Katikati may be able to supply the correct 6V resistor

best luck
Rob

[Big D]

Gidday all,

Thanks for the replies. Yes, I reckon you are spot on with the resistor being the wrong type. I did some more measurements tonight with the voltmeter. With just the ignition switch on, the voltage is 6.1 volts on one side of the resistor and 1.63 volts on the coil side of the resistor.

When the inspection lamp switch is turned on (without the inspection light plugged in) the voltage on either side of the resistor is 5.87 volts and 5.45volts.

Somehow it still seems to drop down to 4.2 volts at the coil but I am unsure how.

As you all say I need to get the correct resistor and remove the little hotwire from the inspection lamp switch and that should do it.

I'll try Ajays Rob.

Thanks all for the help.

[Lynn Eades]

Heres some pics. The resistor is thewhite ceramic on the left side (close up)

[Big D]

Hi Lynn

Thanks for that. It is quite different from the one on my panel. I'll do some hunting and see what I can find.

Cheers

Darryl