Can anyone tell me where the external resistor on a '78 is located and what is looks like? I would like to test it. Thank you in advance for any info.
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1978 FJ40- external resistor (1 Viewer)
- Thread starter erm6266
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It's in the loom afaik. Something like this Igniter Plug
- Thread starter
- #3
Thank you Pith, I guess I have to learn what the loom is now.
The loom is the "wiring loom" or "wiring harness"
The resistor is a length of resistance wire. The black and yellow one I think.
If not, the brown [or grey?] thick wire that connects to the b&y wire.
Hopefully someone will know for sure.
The resistor is a length of resistance wire. The black and yellow one I think.
If not, the brown [or grey?] thick wire that connects to the b&y wire.
Hopefully someone will know for sure.
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‘78 has a 10ga PINK Yazaki resistor wire in the main harness. IIRC it starts around the Fusible Link connection point, on the passenger side or the battery positive terminal, and runs to near the Choke Pull Switch, behind the dash.
The Yazaki replaced the Ballast Resistor in ‘78.
The Yazaki replaced the Ballast Resistor in ‘78.
- Thread starter
- #6
So, the resistor is a wire now? Interesting. My issue is I have no spark. Replaced the coil and coil wire to the distributor. Also replaced the ignition switch. When I turn the key on, no voltage to the coil. However, If I use a jumper wire from the positive side of the battery to the positive side of the coil I get voltage to the coil when the key is on and the engine starts instantly. When I remove the jumper wire while the engine is running, the engine dies. I am really stumped on this one. Checked all the fuses (that I could find), checked all grounds, checked continuity on all the wires, and still can't find the issue. Several people tell me to replace the external resistor. So, now I am learning that the resistor is a wire. I'm a little new to this and appreciate any advice. Thx members
The pink wire in the link pic I gave {I thought it was brown] should be the wire.
You may have to trace it back to the ignition switch {is that where it goes?} to test it's continuity, and check the ignition switch is ok as well, to make sure 12v is getting to the wire.
You may have to trace it back to the ignition switch {is that where it goes?} to test it's continuity, and check the ignition switch is ok as well, to make sure 12v is getting to the wire.
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- #8
Well, I looked at the photo and not seeing a pink wire. I'm I missing something? Thx again
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- #9
It's the one connected to and above the black and yellow wire. It looks kinda very light pink, almost white
Here is a bit more info on the yazaki.
forum.ih8mud.com
forum.ih8mud.com
forum.ih8mud.com
Replaced Starter now there is no spark
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)
forum.ih8mud.com
1978 FJ40 to 1987 FJ60 Igniter/Dizzy question
I have a friend that is wanting to add the 1987 FJ60 Igniter/Dizzy to their 1978 FJ40. Having just completed documenting a 1978 harness, and going by some notes gathered from Jim C., Pin _Head and others over the years, I know that the 78-80 FJ40's used the infamous Yazaki Ignition Resistor Wire...
forum.ih8mud.com
Electrical Wiring on Ignition
In trying to solve the electrical problems with my 78 fj40 I ran across a very interesting unexplained puzzle, atleast to me. What is was doing: Smoking behind the dash whenever the ignition switch was on. What I did: tore down the dash and started searching for the rogue wire(s) What I...
forum.ih8mud.com
- Thread starter
- #12
I checked and not finding the pink 10 gauge resistor wire. I checked my 40 and it shows the production date of Dec 1977, but it's a '78 year model. With that production date, would it have the pink resistor wire? Thx members
In this pic 73 FJ40 ignition wiring [just an example, coz I assume yours is a column key?]
The b&y wire should have 12v when the ignition is on.
If it does, but the coil still has no volts, there is problem somewhere, like a break, or a fried ballast wire. Unless there's a fuse or relay between the switch and the coil?
If the b&y wire has no volts when ignition is on, there is another problem with the switch or fuse etc.
Your 40 *should* have a b&y ignition /coil wire connected to the switch. It needs 12v in the on/run position regardless of the type of ignition switch.
The b&y wire should have 12v when the ignition is on.
If it does, but the coil still has no volts, there is problem somewhere, like a break, or a fried ballast wire. Unless there's a fuse or relay between the switch and the coil?
If the b&y wire has no volts when ignition is on, there is another problem with the switch or fuse etc.
Your 40 *should* have a b&y ignition /coil wire connected to the switch. It needs 12v in the on/run position regardless of the type of ignition switch.
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- Thread starter
- #14
thank you again. I will check it tomorrow. What is the difference of a resistor wire and ballast wire? Are they not the same?
When I turn the key on, no voltage to the coil. If I run a jumper from the +battery to the +coil, I have voltage to the coil with the key on and It starts instantly. If I remove the jumper while the engine is running, it dies. I replace the ignition switch last week, no help. This is been a real mystery to me. It's wearing me out
Yes, sorry, they are the same.
Also , I assume you tested the fusible link?
- Thread starter
- #16
If you are referring to the main engine fuse near the coil, yes. Also checked the coil fuse in the fuse box. Both good
I think your 40 fusible link should look something like this Fusible link and fuses issue
And afaik it's near the battery. Or not.
Someone will know more about 40's fusible links.
And afaik it's near the battery. Or not.
Someone will know more about 40's fusible links.
- Thread starter
- #18
I've haven't seen a fusible that looks like that. I will definitely look for it, if I can find it. Thanks so much
Let’s back up for a moment, is your ‘78 40 a US Spec 40? Does the wire harness appear intact and wrapped?
Your ‘78 is a 12/77 manufactured date... mine is a 01/78.
If yours is US Spec, I would expect the 10ga pink resistor wire to be spliced into the 10ga Black-Yellow wire, in the area I mentioned earlier.
This ‘78 wiring schematic
EDIT: —> http://www.globalsoftware-inc.com/c...ics/FJ40/1978FJ40/1978fj40_wiring_diagram.pdf
came off of @Coolerman’s site. The coil is on the left side and the fusible link is to the right of the coil.
Post #7 of this ('78 Fusible link........really? )
shows what a fusible link looks like... it attaches to the battery+ terminal and @Coolerman sells them and their associated terminals, etc.
If you still need help, please post pictures of your coil, distributor & battery wiring and the wire colors of any wires that are not clear in your pics.
Your ‘78 is a 12/77 manufactured date... mine is a 01/78.
If yours is US Spec, I would expect the 10ga pink resistor wire to be spliced into the 10ga Black-Yellow wire, in the area I mentioned earlier.
This ‘78 wiring schematic
EDIT: —> http://www.globalsoftware-inc.com/c...ics/FJ40/1978FJ40/1978fj40_wiring_diagram.pdf
came off of @Coolerman’s site. The coil is on the left side and the fusible link is to the right of the coil.
Post #7 of this ('78 Fusible link........really? )
shows what a fusible link looks like... it attaches to the battery+ terminal and @Coolerman sells them and their associated terminals, etc.
If you still need help, please post pictures of your coil, distributor & battery wiring and the wire colors of any wires that are not clear in your pics.
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OK erm6266, I'm going to try and help you with a little humor along the way. Don't take offence. It's good info for you to learn and I will continue to help if you wish.
I looked at the 78 wiring diagram thanks to Coolerman. Now, here's the deal:
Points style distributors can not survive on 12V, they will burn soon. Soooooooooooo..........
Most automakers use two wires to the coil. One is a full 12V during starter motor operation because the starter tries to suck all the juice and the coil needs some too. This 12V is supplied only when starting. Then the other wire takes over. This other wire is run thru a resistance to lower the "Run" voltage to 8V or 9V so as to "save" the points/points contacts. This system uses a coil that says "externally resisted" on it because it is externally resisted by the system, as you will see. Some folks do not use any resistance system wiring. Those folks use a internally resisted coil. Resistance is "built in" to the coil. Those people are communists and their hair will fall out. So anyway...........
There are two ways that resistance is introduced. Earlier FJ used a regular old resistor. A big ceramic block with a coil. It is referred to as a Ballast Resistor. This was mounted on the firewall or near coil.
Then some genius decided that a long piece nickle/blabium wire would act as a resistor. But it had to be so long that it was doubled back in itself inside the harness. Travels all over the place. This is referred to as Resistance Wire. A real hoot of an idea. It's better to snip it on both ends and install a good old ceramic one.
With either of the two resistance methods, there is a "bypass" wire. That's the coil wire that's "hot" only during cranking. That there wire is supplied by the starter solenoid. Sometimes labeled "R". It goes directly from solenoid to coil.
Now the problem here, as usual, is that we don't know very much about this problem. The poster knows nothing about ignition and has chosen to ask about how to check some thingy. He has a some sort of reason for bypassing an exact explanation of the problem and just ask for help.
1. First we see "where is the external resistor?"................on this thing.
2. Then "what is a loom?" vs harness/bundle/wiring
3. Then he/she is told to chase a Pink Yazi wire. Holy Moses!
4. Then we have "no spark".
5. Wait, it's no voltage to the coil with key on. (I hope)....But we don't know if it fires at that point.
6. So we hook up 12V directly to the coil. It starts!!!!! So we do have spark!!!! Awesome. The key was on and a jumper was hooked up, you then had Voltage.... but.....but.......... it wasn't because the key was on, you bypassed the key. It did start due to that wire. But not exactly sure if it "fired" without that wire. Not start, but fire. That...... we need to know.
7. You can continue to guess and chase the Pick wire and wonder what it's all about or we can get back to basics with you doing some tests and report the results.
8. Get the Coolerman 78 FJ40 diagram downloaded so we can talk the same language. I am not a Toyota expert but probably can figure out this deal with the help from the crew here who do know FJ40.
9. Maybe I can get you to do a firewall ballast resistor. But some here will revolt to that idea so as to be "original". I really don't know if "original" is a ballast resistor or resistance wire for 78. The diagram shows the symbol for a resistor. That could also be the Japanese way of showing a long wire, and you seem to have that long wire.
The End.
I looked at the 78 wiring diagram thanks to Coolerman. Now, here's the deal:
Points style distributors can not survive on 12V, they will burn soon. Soooooooooooo..........
Most automakers use two wires to the coil. One is a full 12V during starter motor operation because the starter tries to suck all the juice and the coil needs some too. This 12V is supplied only when starting. Then the other wire takes over. This other wire is run thru a resistance to lower the "Run" voltage to 8V or 9V so as to "save" the points/points contacts. This system uses a coil that says "externally resisted" on it because it is externally resisted by the system, as you will see. Some folks do not use any resistance system wiring. Those folks use a internally resisted coil. Resistance is "built in" to the coil. Those people are communists and their hair will fall out. So anyway...........
There are two ways that resistance is introduced. Earlier FJ used a regular old resistor. A big ceramic block with a coil. It is referred to as a Ballast Resistor. This was mounted on the firewall or near coil.
Then some genius decided that a long piece nickle/blabium wire would act as a resistor. But it had to be so long that it was doubled back in itself inside the harness. Travels all over the place. This is referred to as Resistance Wire. A real hoot of an idea. It's better to snip it on both ends and install a good old ceramic one.
With either of the two resistance methods, there is a "bypass" wire. That's the coil wire that's "hot" only during cranking. That there wire is supplied by the starter solenoid. Sometimes labeled "R". It goes directly from solenoid to coil.
Now the problem here, as usual, is that we don't know very much about this problem. The poster knows nothing about ignition and has chosen to ask about how to check some thingy. He has a some sort of reason for bypassing an exact explanation of the problem and just ask for help.
1. First we see "where is the external resistor?"................on this thing.
2. Then "what is a loom?" vs harness/bundle/wiring
3. Then he/she is told to chase a Pink Yazi wire. Holy Moses!
4. Then we have "no spark".
5. Wait, it's no voltage to the coil with key on. (I hope)....But we don't know if it fires at that point.
6. So we hook up 12V directly to the coil. It starts!!!!! So we do have spark!!!! Awesome. The key was on and a jumper was hooked up, you then had Voltage.... but.....but.......... it wasn't because the key was on, you bypassed the key. It did start due to that wire. But not exactly sure if it "fired" without that wire. Not start, but fire. That...... we need to know.
7. You can continue to guess and chase the Pick wire and wonder what it's all about or we can get back to basics with you doing some tests and report the results.
8. Get the Coolerman 78 FJ40 diagram downloaded so we can talk the same language. I am not a Toyota expert but probably can figure out this deal with the help from the crew here who do know FJ40.
9. Maybe I can get you to do a firewall ballast resistor. But some here will revolt to that idea so as to be "original". I really don't know if "original" is a ballast resistor or resistance wire for 78. The diagram shows the symbol for a resistor. That could also be the Japanese way of showing a long wire, and you seem to have that long wire.
The End.
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