Electrical Wiring on Ignition

[Silascrum]

Would the resistor ran on earlier cruisers (pre 78) or later cruisers (post 80) do the job? Does anybody know the "ohm and amp rating" needed for this ballist resistor?

This has been such a huge help guys, thanks so much.

 

[FJ40Jim]

The resistor from earlier cruisers would probably be OK. Don't worry about the watt rating, cause you're not gonna get this resistor from Radioshack. Just get a generic automotive ballast resistor from local parts store.

There is no resistor on 81-later cruisers.

 

[Silascrum]

Sounds easy enough. Thanks again.

 

[Silascrum]

I don't think there is a 'generic' automotive ballast resistor. I have found that the resistor that came in the 1977 fj40's had a resistance of 1.4 ohms. Would a resistance of 1.35 ohms work?

 

[Pin_Head]

Yes. It isn't rocket surgery.

 

[FJ40Jim]

I don't think there is a 'generic' automotive ballast resistor.

Just ask the parts store for ballast resistor to fit a 1970 Dodge dart w/ slant 6 engine, automatic and airconditioning. None of the particulars matter, it just makes the drone feel better looking it up.

For $3 you will get a generic ballast resistor.

 

[Silascrum]

<---newbie

Got it!

putting it on as you read this...

thanks again

 

[KOOTENAY KRUZER]

Sure you can get rid of the resistor. You have to get a new coil that is designed to run at 12V instead of 6V. That's all there is to it.

If you get rid of it, then you will lose the reliable start during cranking feature. The battery voltage drops to about 8V or less during cranking and this is marginal for making a spark with a 12V coil. Toyota eliminated this feature in 1981, but kept it in Canada.

The resistor is not the cause of the wire burning. Shorting out the wire causes it to burn, because it is not fused. Shorts will burn out the wire, resistor or not.

I'm surprised - I thought '78 was the last year that Toyota sold spark ignition engines in Canadian LandCruisers, I don't think I've ever seen an originally Canadian FJ 40, 60, or 70 with a gas engine after the '78 FJ40 market year. AFAIK, all LandCruisers here after the BJ70 were marketed under the Lexus name. I could be wrong, though, waiting for enlightenment.

 

[Pin_Head]

The 1981 schematic diagram shows the ballast resistor with the designation "Canada only". I don't get a chance to open the hood on Canadian cruisers often enough to know if it is true or not. I will be up in Vancouver in 2 weeks, so if I see one, I will take a peek.

 

[Silascrum]

Ballast resistor installed. turns over, cranks, let off the key and it dies.

I also replaced a fuel hose to the filter.

Not sure if it is an electrical problem, or not enough fuel. When I press the gas nothing happens, which makes me think its not getting fuel to the engine. I can hold the ignition to start (which I know itsn't good) but that is the only thing that will keep it running, but only for a few extra seconds. (which I guess is when the starter cuts off) What do you all think?

Yet again, stuck...but not giving up.

I'm no mechanic. I think I may be in over my head.

 

[Pin_Head]

Are you sure it is wired correctly?

This is the kind of symptom you would have if the wire from the key to the resistor is not connected and the only wire powering the coil is the ballast resistor bypass wire from the starter solenoid. You get this symptom if the resistor wire is broken too. The stock coil wiring has two black wires with yellow stripe: One from the key (which is thicker) and one from the solenoid. The solenoid bypass wire connects directly to the + lug of the coil. The wire from the ignition switch connects to one end of the ballast resistor and the other end connects to the + lug of the coil.

You can find a schematic diagram here:
http://www.yankeetoys.org/documents/wiring_diagram_78_fj40.pdf

Note that the start and accessory positions of the ignition switch and their wires are incorrectly switched in the diagram. Black with white stripe is the wire to the starter motor.

 

[bsmith123]

run pos

x2 you have a wire for starting that works with the key in the start pos and another when the key is in the run pos

your not getting voltage from the run pos to the coil

 

[FJ40Jim]

quick test

Turn the key to the run position.

Measure V between + terminal on coil and ground. Usually is somewhere in 7-10V range.

 

[Silascrum]

Used a circuit continuity checker and found that I'm not getting any current on the other end of the ballast resistor (going to the coil). I've been jumping it off to try and start it but I'm gonna charge the battery and then test it again. I'll also check the voltage then. We'll see where we are after that.

Almost there...

 

[bsmith123]

volts

if its cranking you should read something at the coil. make sure you haven't hooked up something wrong.

if you need it running you could run a wire from the batt to the + side of the coil and it should start and run normal then but you can't shut it off w/o pulling the wire

if you do that disconnect the other wire it might be going to ground somewhere and you dont want to fry it.

 

[Silascrum]

Got it running now. I just took off the ballast resistor I purchased and that did it. I received my FSM in the mail and noticed what probably is an external resistor on top of the ignition coil. I am not sure the purpose of the resistor wire, but everything seems to be fine now. I just have an almost dead battery I need to charge. No hot wires, no smoke, and its running smooth.

It was good to drive it around the block.

Am I right about the external ballast resistor. I can post a pic of that would help. I tried to open it up but stripped a screw in the process so the casing is not coming off of what is labeled the "Ignition Assembly"

I'm pleased unless someone tells me I may still have a problem with not enough resistance. Or time will tell.