Coil Relay Mod Question

[Pat Conlon]

Thanks Gavin (fj-f3a) for your help in this thread. Your expertise is apparent.

A question to the OP Canada-Mach and to Dieselman7.3.

Here is the wiring diagram we use showing the wiring of the coil relay:



We want your input. What is confusing about this ^^^ diagram?
What can we do to make this wiring diagram more clear?

In our Modification Files we have this Coil Relay topic archived:
http://www.fjowners.com/index.php?topic=1755.0

Thanks for the help guys. If our existing diagram is giving you heartburn, help us make it better.

Cheers

Pat

[Tuned forks]

Pat, when I made the coil relay mod before the 2019 WCR, that diagram was particularly useful.  The colors were spot on for my FJ.  It took awhile to find the wires and I was meticulous in reading the diagram and making sure the wiring was correct.  Many such diagrams are black and white.  Having that one in color helps as well.

Joe

[Dieselman7.3]

Thanks Gavin (fj-f3a) for your help in this thread. Your expertise is apparent.

A question to the OP Canada-Mach and to Dieselman7.3.

Here is the wiring diagram we use showing the wiring of the coil relay:



We want your input. What is confusing about this ^^^ diagram?
What can we do to make this wiring diagram more clear?

In our Modification Files we have this Coil Relay topic archived:
http://www.fjowners.com/index.php?topic=1755.0

Thanks for the help guys. If our existing diagram is giving you heartburn, help us make it better.

Cheers

Pat

This diagram is very helpful. The only part that confused me was the red/white wire I gues I didn't realize it was being used as the signal wire for the relay.  So if I'm correct that is the factory power wire to the coils.   My only question now is. What size fuse should I use from the battery? I have a ton of relays and etc. so I think I'm going to go with two separate relays and fuses   Thanks

[fj-f3a]

Make sure you choose a "Quality, multi-strand cable" to run from the battery to the relay(s). I would recommend a cross sectional area of at least 4mm square. You could comfortably use a 25A fuse with this cable and it will give you power in reserve for, say, driving lights, or a good horn. The larger the cable, the less Voltage Drop.

Use the correct crimping tool and connectors. I do not have a ring type terminal to show you but you will get an idea of what I mean by the terminals in the photo.
You should be able to purchase a Quality Inline Fuse Holder with 4mm "Flying Leads". Simply crimp a 4mm (yellow) ring with the correct size hole (8mm, I think) to one cable and connect the other end to the 4mm relay cable using the tunnel connector (shown). Try to avoid soldering unless the joint is "Really Well Supported". Solder joints and vibration don't mix!

With regards to the terminals in the photo, Red insulated terminals are for 1.5mm cable, Blue for 2.5mm and Yellow (shown) for 4mm square cable.

Being short in length, the wires from the relay to the coils need only be 1.5mm or 2.5mm square. Again, use the correct crimp tool to terminate the brass spade terminals.
The starter motor solenoid as depicted in the diagram Pat posted, is the best to connect to.

Gavin

[Dieselman7.3]

4mm should be what about 10ga wire?  That's what I was planning on using and the heat shrink but connectors tend to hold good against corrosion (typically what I use on vehicles and ATVs so they stay water tight) and just to be on the safe side I probably won't splice anything else to that circuit.  I don't mind spending the little extra for more wire/fuse/ relays to keep things on there our circuit (not saying it's bad too just my own opinion/ preference)

[fj-f3a]

10 AWG = 6mm

12 AWG = 4mm 

[Dieselman7.3]

10 AWG = 6mm

12 AWG = 4mm 

Thank you

[Canada.Mach]

Got a bit sidetracked here, sorry for the delay. But, thanks for all the help everyone! I'll be rewiring this sometime this week hopefully.

And Pat, between the diagram and post everything is pretty well explained I'd say. If I'd done it myself I'd have been double checking that post every 2 minutes, and probably would have turned out alright. Or at least known where I was being held up (maybe the jumpers for orange/gray would've got me confused, I think). Why the mechanic got mixed up the way he did, I couldn't say- I had printed out the diagram and post you linked for him.

I'm pretty inexperienced mechanically, if something on the car/truck breaks I'll learn to fix it and that's about it. The bike usually goes to the mechanic because he'll be smarter and faster (not much summer in Canada), plus I guess I'm a bit intimidated and don't want things to get crashy if I screw up. But I'm trying to find the time to ease myself into bike repairs/maintenance, so I'm learning! I've never touched anything electrical before, as you can see by my game of 20 questions on here!

As for the diagram, maybe one improvement that could be made is to identify the wires as "old" or "existing", and "new"? But, like you say- that diagram has been used for years by members, so maybe there's no reason to bother overexplaining things just because I came along and got confused!
Gavin's post on Page 1 clears things right up for me, the diagrams. It shows pretty clearly what's going where, and how the relay can be bypassed to hookup in the original configuration.

Thanks again everyone, I'll report back when I've got it working or blown something up!

[TomJK]

Hi

Just a warning, I noticed on my FJ1200 that the earth wire connected on the side of the coilfitting was very corroded, clean this, otherwise you might have trouble...check the main earth wire connected to the back of the engineblock too, while you're at it...

Cheers, Tom.

[FJmonkey]

I wanted to give this topic an update. I have been helping another owner with an 89' with starting problems. Very fresh engine, 4 brush starter, rebuilt carbs, new AGM battery on a tender, good fuel pump etc. It got to a point that it just would not start. Prior to this, once started it ran quite well.

Fuel, air, fire.

Its getting a proper amount of fuel. The air, carbs, filters looked good in my opinion. I recommended the relay mod for the coils. A little time gathering the materials and drive south, the fun begins. Prior to this mod, the bike failed to start 3 times in a row with time between to charge the battery. It was clearly getting fuel (you could smell it) and the starter spun the engine, I could see the choke linkage moving on the carbs. The plugs sparked but hard to tell how good the spark was. Measuring the voltage before and after at the coils was a good indicator. Before the mod the voltage drop was 2.1VDC. After the mod 0.3VDC.

After the mod the bike fired up like it should. It now has over 5+ starts in a row over the last few days with zero issues. For $15 to $20 in parts and a little time, you can get full battery voltage to your coils. These bikes are aging, some systems need an update/bypass.