Replaced Starter now there is no spark (1 Viewer)

[huminajumina]

Do you have voltage with key on & while cranking? My ignition switch was wired wrong & cut out power while cranking...it wasn't a problem until I cleaned up some wiring & removed what ever was feeding back (making it work)

 

[Coolerman]

"The resistor only drops voltage when there's current running through it.
In a points system, if the points are closed you will see 7-9v but if the points are open you will see 12v because the circuit is open.
Similarly for an electronic system, if the igniter is drawing current then the resistor will drop voltage (IR) and you'll see lower voltage at the coil.
If the igniter is not drawing, you'll see 12v."

Yeah I know that, what I was really wondering was, if he is running a Troll Hole dizzy and is powering it with the BY wire, which on a 78 has the resistor wire in line with it, how well does the Troll Hole dizzy work with the reduced voltage? Must not really matter as he has sold a lot of them i'm sure to 78 owners... A lot of modern electronics, especially DC, are designed to work on a wide range of input voltages.

 

[Pin_Head]

I think the wire with the integrated resistor started in year model '79. That would be everything with a build date of 9/78 and later. It is easy to spot because the wire has "resistor" printed on it.

 

[edwjmcgrath]

"The resistor only drops voltage when there's current running through it.
In a points system, if the points are closed you will see 7-9v but if the points are open you will see 12v because the circuit is open.
Similarly for an electronic system, if the igniter is drawing current then the resistor will drop voltage (IR) and you'll see lower voltage at the coil.
If the igniter is not drawing, you'll see 12v."

Yeah I know that, what I was really wondering was, if he is running a Troll Hole dizzy and is powering it with the BY wire, which on a 78 has the resistor wire in line with it, how well does the Troll Hole dizzy work with the reduced voltage? Must not really matter as he has sold a lot of them i'm sure to 78 owners... A lot of modern electronics, especially DC, are designed to work on a wide range of input voltages.

That does bring up an interesting point. Although I'm sure the trollhole will work on a wide range of DC voltage, I would expect that it would wreak havoc if it was powered by a voltage that was 12v but dropped down to 7-9 volts (and even lower with overshoot and ringing) with every spark. I would strongly recommend running a solid 12v to the trollhole ignitor power wire (IIRC red), not something that's fed through a resistor or resistor wire.

 

[Coolerman]

Thanks Pin_Head, did not realize it was that late in the model year. His is a 2/78 so no resistor wire. That also explains it working fine with the Troll Hole dizzy. Just wonder if anyone has added the Troll Hole dizzy and had issues if they have the resistor wire? I will search for this as I have been away from MUD long enough not to know if this has been talked about already. I'm adding that resistor wire start date thing to my notes. Off the top of your head do you know when it ended?

 

[Curt]

I had heard the 78 may include this resistor but sounds like mine doesn't have it if the wire says resister right on it. Going to grab a cap and rotor today or tomorrow. I will keep you updated.

 

[Pin_Head]

I'm just guessing about the change date, but it is based on what I have seen between 78 and 79 model 40s.

 

[Curt]

I did run a direct wire from b+ to coil + and still didn't get it to start so it it isn't the resistor wire. Went to the local parts store and they didn't have a cap and rotor for this unit. It is fairly new, do caps and rotors fail like this? One thing i did notice was the spark from the coil to the distributor was that of an orange colour not a bright blue if that makes a difference. Maybe i will take a few pictures of the current setup.

 

[Curt]

Ok so i snapped a couple photos of the setup here.

A. Larger BY wire that supplies voltage to coil and red wire from dizzy hook up
B. Black wire from dizzy is hooked up
C. Small BY wire this should be the resistor bypass wire (was hooked up to old ignitor) but shows 12volts with key on
D. Another small BY wire that was never hooked up to old system but fluctuates low voltage, could be due to oxidation from not being used.
E. Should plug into this to get the extra voltage from starter
F. BY wire with connector, plug the starter (E) into this and be used as the bypass but it also shows 12 volts
G. Black wire from dizzy connected to jumping wire for test purpose.

 

[Coolerman]

Thought I would post this information about the Yazaki Resistor Wire ignition hookup here as it may help folks understand it better.

There is a lot of confusion about this resistor wire and the ability of the 1978-79 FJ40 owner to see it. On the harness I documented there is no way you would ever know it was there. This PINK wire, with Yazaki Resistor Wire clearly stamped on it, was spliced in between the 10ga BY wire from the key switch and the 10ga BY wire going to the connector that connected to the igniter. Unless you un-taped the harness you would think it was a 10ga BY wire all the way from the key switch to the igniter connector.

For the archives: This wire is clearly stamped .75 ohms per meter. The wire is 63 " long the math works out to 1.2 Ohms, same as the ballast resistor it replaces.

There is also a lot of confusion on how power is fed to the igniter and the coil. Why? Well as you can see by looking at the drawing, there are FOUR wires all coming from the key switch to the igniter area.

The large BY 10 ga wire is the one that has the resistor wire spliced into it. This is the wire that connects to the +side of the coil. It's 10 ga for a reason: When the negative side of the coil is grounded by the igniter or say Troll Holes dizzy, a LOT of current flows through the coil!

Spliced off the 10 ga BY wire is the 18ga BW wire that goes to the starter bypass relay. When the starter engages, a relay in the starter closes and puts full battery voltage +12V on the BW wire, which, because it's spliced into the 10ga BY wire, goes to the COIL giving the coil full +12 volts as long as the starter is engaged. Note that this is an 18ga wire! If you crank and crank the truck trying to start it, this wire WILL get warm! It is supplying the coil with full power through an 18ga wire.

The other 18ga BY wire spliced into the 10ga BY wire (with a bullet connector on it ) is for the noise suppression capacitor to plug into. This is the one everbody asks, "What plugs in here?" Usually the capacitor is long gone.

That brings us to the 16ga BY wire that comes from a splice into the 10 ga BY wire, BEFORE the resistor wire. This wire carries the full battery voltage +12 volt from the key switch, and is what powers the IGNITER, not the coil.

Please note that this circuit IS NOT FUSED! If you short one of these wires to ground with the key switch on you WILL melt wires!

Also: These drawings are not the best labeled in the world. They were done for me, and may be missing information, that someone, not familiar with the overall harness layout or circuit structure, would need to fully understand them. Please feel free to ask me to add labels if you see something that makes no sense without them.

Hope that helps folks understand this circuit.

 

[Coolerman]

Ok so i snapped a couple photos of the setup here.

A. Larger BY wire that supplies voltage to coil and red wire from dizzy hook up
B. Black wire from dizzy is hooked up
C. Small BY wire this should be the resistor bypass wire (was hooked up to old ignitor) but shows 12volts with key on
D. Another small BY wire that was never hooked up to old system but fluctuates low voltage, could be due to oxidation from not being used.
E. Should plug into this to get the extra voltage from starter
F. BY wire with connector, plug the starter (E) into this and be used as the bypass but it also shows 12 volts
G. Black wire from dizzy connected to jumping wire for test purpose.

A. That looks correct.
B. That looks correct.
C. No, that is the old igniter power wire. The bypass wire is the BW wire near the starter. It is spliced into A. Wire C will have +12V when key is on. Not needed in your setup.
D. What do you mean it fluctuates? How low does it go? This is where the radio noise suppression cap plugged in.
E. This is the harness side bypass wire that is spliced into A.
F. This is the starter side of the bypass wire.

You can plug Wire E into Wire F, but since Wire C is not used in your setup, you will not gain anything. Damn this is going to be confusing....

 

[78fj40mg]

It may coincidentally not be the starter at fault here, this may sound off the wall, but it could be the ignition cable switch, a faulty switch disables the ability to start the engine, these switches go bad without any warning. Many years ago I had a similar issue with my first FJ40 and replaced the ignition cable switch and she started right up, These sell for about $20 US so can't go wrong by replacing it.

http://www.cruisercorps.com/electrical/ignition-switch-cable/ignition-cable-switch-3-1969-1984.html

I have No affiliation with Cruiser corps.

 

[Curt]

Thanks Coolerman. It looks like i have it wired up correctly (for this application). I can take a look in my harness for the pink resistor wire just to see if its in a 2/78. Where do you think it might be placed? I guess my problem does reside in the cap and or rotor so i guess i will try to track down a medium cap for this unit. I did look yesterday but no parts stores in the area carry them.

 

[Curt]

78fj40mg read my mind, I ordered one of these on the weekend. I did take the old one apart and the copper plates inside the switch are very warn and copper dust everywhere. Figure if it isn't the problem it needs to be replaced anyways so its worth it.

 

[Coolerman]

Thanks Coolerman. It looks like i have it wired up correctly (for this application). I can take a look in my harness for the pink resistor wire just to see if its in a 2/78. Where do you think it might be placed? I guess my problem does reside in the cap and or rotor so i guess i will try to track down a medium cap for this unit. I did look yesterday but no parts stores in the area carry them.

Depends on which end you want to start un-taping. From the passenger side of the main chassis harness, the pink wire will start about where the rear chassis harness connectors are coming out of the main harness so you would start un-taping there.

From the drivers side of the main harness the pink wire starts where the key switch harness branch joins the main harness. If the harness is installed it would be easier to access the main harness where the rear chassis connectors are on the firewall. I can only ass-u-me that Toyota put these things in the same location in all harnesses. The pic shows how it's spliced to the 10 ga BY wire. That pic is of the drivers side close to the headlight switch. You can see the headlight switch bulb.

 

[Curt]

Ok dug in right by the passenger connectors that you suggested and struck gold. A pink wire connected to the BY

 

[Coolerman]

Ah ha! So your FJ40 is a verified 2/78? That may mean the resistor wire in fact started in the 78 model year.

However, until you replace the cap and rotor we still don't know if powering the Troll Hole dizzy from 7-9 volts is a problem. I mean it did run for how long hooked up this way? Of course the variable is, it WAS hooked up to the bypass wire which gave it +12 volts to begin with, then dropped to 7-9 volts after starting. Maybe long term this damages the module in the dizzy to the point it now won't fire correctly? You did mention the weak spark. I just don't think the cap and rotor are bad. Those things last years...

 

[Curt]

I can run the vin but the plate on the door jam says its a Feb 78. The starter was grinding and not engaging so figured the solenoid was toast, took the starter apart and rebuilt it. Installed it fired up on second crank then the starter failed again. So picked up a new starter and installed it in and haven't gotten it to fire since. If the dizzy isn't getting enough voltage then why didn't it fire when i connected the coil directly to the battery and gave it the 12v? If it was the resistor not giving it enough then that should have done it. Not sure what else to do. There is spark going to the dizzy, it jumped a good distance maybe 3/8 or so. It just didn't seem very hot. We get spark jumping from dizzy to spark plug wires but its small to non existent. So it must be something inside the dizzy if it still wont fire after being connected directly to battery like pin_head suggests.

 

[Pin_Head]

The starter was grinding and not engaging so figured the solenoid was toast, took the starter apart and rebuilt it.

Starter grinding and not engaging is a Bendix drive / ring gear mechanical problem, not a solenoid or starter motor problem.

 

[Coolerman]

Wait a minute! Are you using the OEM coil with the Troll Hole dizzy? If so that coil requires the ballast resistor wire but the electronics inside the distributor are expecting +12V just like the OEM coil/igniter setup. Change your hook up as follows and try it:
Wire A: Connect ONLY to the coil
Wire C: Connect ONLY to the red wire on the dizzy.

Gotta head out to run errands, but will check this thread when I get home. Hopefully this might fix it!