View Full Version : FJ40 Wiring Harness

07-19-2011, 11:14 AM
Does anyone have any advice on a new wiring harness for an FJ40? Last year I had smoke come billowing out from behind my dash where several wires in the main cluster fused together and since then it has all been downhill. In fact, it has gotten bad enough that I have not been able to drive my 40 all year.

I have seen several suggestions online including: painless, centech, Ez Wiring and build your own. I am not sure I have the time to build my own so the kit seems like a better fit for me. Painless seems really expensive and I could get the same setup from EZ without the extra cost.

I would also appreciate any suggestions you have like the number circuits I should get. Obviously extra is better, but how many extra? Is 14 good or should I just go with 18 to be safe?

For those of you not familiar with my 40, it is a 1978 with a SBC in it. I am not running onboard air but may one day. I have a CB, HAM and a radio. There really is not a whole lot of extras on my car (yet).

Thanks for your advice.


07-19-2011, 11:25 AM
That's a bummer Justin. I don't have any suggestions or insights on which kit to go with. I do know that Coolerman on MUD has many of the connectors available if you are also needing to replace them. He also does rebuilding of the stock harness as a service. All that said, he recently indicated that he would have to suspend those activities to focus on building a house and shop. When you get around to doing the work, let me know if you'd like an extra hand.

07-19-2011, 11:35 AM
Thanks Ricardo. I did read through some posts from coolerman. I think most of his connectors are for early model 40's.

Right now I am leaning toward a whole new harness just to get some fresh wires in there. The previous owner did so much splicing and dicing I am not sure what is what. I also know I will need a new fuse box, The old one is melted in spots.

I hope to see you at the next meeting. Work has kept me away from the last few.


07-19-2011, 11:39 AM
painless and ez harnesses won't be a bolt in solution, they are a universal harness. they won't have the connectors for your switches and cluster, you will have to splice those in.

if you need, i have a couple of harnesses that you can rob parts from to fix yours. neither are good for complete harnesses, one was p.o. butchered and the other was cut out of a wrecked vehicle.

07-19-2011, 11:59 AM
I would either go find a harness out of a '78 in a boneyard like Classic Cruisers in Salida or cruiserparts.net or go with the Painless harness since you've got the SBC anyway. The stock replacement will be harder to find and will probably take some work, the Painless will probably take more work but may end up being more of what you are looking for in the end.

Coolerman hasn't really been able to find many key connectors for I think '74 and newer Cruisers. He could probably rewire it all in weatherpak connectors though, but you'd have to send him a good clean template. And like Ricardo said he won't be doing any work until his house is done this fall/winter and he has a chance to get his garage back.

07-19-2011, 01:35 PM
Since you've got the SBC already....

I'd probably go painless or EZ. I've played with plenty of Toyota harnesses, and they really are the best out there, but once you have to start hacking and splicing them you might as well just build your own. That way, you don't have excess wires lurking in the harness to cause you trouble later on.

As to the weatherpak comment: do it. If you are going to make your own, the weatherpak system is simply awesome. Very consistent crimps, excellent weather protection for the plugs, and easy to do. I don't know how I went so long without it.

FWIW--whenever I get to wire my 45, I will go with painless or EZ and weatherpak connectors. The hardest part of using a universal harness is having to modify it to work with the Toyota turn signal setup, and splicing on connectors for the ends.


07-19-2011, 01:49 PM
I agree with Subz... I'd find a donor 78 and make it as painless as possible.

If that doesn't sound good, I would drop the coin on a new one from Painless, they are more expensive, but have an excellent reputation and the labeling of individual wires on the vinyl would be a dream for me.

No two ways about it, its gonna take a lot of work. I would think the Painless kit would actually smooth out the process of mating the SBC to the Yota stuff.

However, I have never done a total rewire myself so take the above advice in light of that confession ;)

07-19-2011, 02:37 PM
If you decide to rewire with a non-OEM harness.....

I rewired an '65 FJ45 with an 'It's a Snap' brand harness (yeah, the name...egad!). Info at: http://www.itsasnapwireandcable.com/zz-20_wire_harness.htm. Despite the cheesy web page, it's a sound product.

Each wire was labeled with its circuit and the only problem was that the taillight wires were a bit too short for a pickup. It was dirt cheap ($130?) but worked very well. I would definitely get an 18 circuit one. I found myself a few circuits short with the 14 circuit one, and having a single circuit for each device makes troubleshooting easier.

While the task was huge, I simply resigned myself to doing a single new circuit each day before work, and within 2 weeks, I had it all done. If you tried to do the whole thing in one weekend, I think it would be very frustrating. I navigated the shoals of the turn signal wiring, but you will need to take your time on that.


Shark Bait
07-19-2011, 05:08 PM
I've got a '78 harness you can start with. It might not be complete, but it would be a start. I'll give it to you.

07-20-2011, 12:26 AM
I've got a '78 harness you can start with. It might not be complete, but it would be a start. I'll give it to you.

Thanks Chris, I might take you up on that. Let me do a little more research and I will let you know. I am in MN this week so I would not be able to get it until at least next week.

Thanks everyone for your advice. Additional advice is always welcome.


07-20-2011, 01:28 PM
I have seen several people suggest moving the fuse box into the glove box compartment. Anyone have any thoughts about this?