New wiring harness for my 78 rd400

[rd400greenhorn]

Hi guys
So, i Want to put in a original wiring harness and combine it with a
Electronic ignition and maybe a Modern battery.

How do I go about it, regarding the wiring harness
Does a 76/77 from economy cycle do the job?

[rd400greenhorn]

 :metal:li

[Dvsrd]

Hi guys
So, i Want to put in a original wiring harness and combine it with a
Electronic ignition and maybe a Modern battery.

How do I go about it, regarding the wiring harness
Does a 76/77 from economy cycle do the job?

Depends. If your 400 is a euro model, there MAY be somewhat/slightly different electrically then å US 400k which is what EC would have harnesses made for. 

[rodneya]

I thought you were putting an M unit on your bike?

If you are switching to aftermarket ignition I would assume that any any parts of the harness that would be different would be removed except maybe the ignition switch connection.
Lights and signals etc are fairly simple. If you dont have the stock ignition or instruments I dont see why you could not even use a 350 harness as it is even less complicated.

[rd400greenhorn]

This is another rd400

So No m unit on this one

[rodneya]

Oops, my bad.
But like I always tell my wife, you cant only have one RD

[m in sc]

what ignition? I mean, no harder than installing one on a stock bike. I think 78 and back was pretty much the same. its  a points model, right?

[SoCal250]

How do I go about it, regarding the wiring harness
Does a 76/77 from economy cycle do the job?

I assume your new '78 is a EU model? If so I think it has a factory CDI, right? I just checked a RD400 EU parts book.

Regarding your question about differences between 1976/1977, 1978 harnesses...
I'm not 100% certain but I believe the only difference between the US 1976/77 and the US 1978 is the addition of a lighting relay on the front of the harness. (CAN models got this relay in 76). See attached RD400E diagram.  All US models are points ignition.

[rd400greenhorn]

The ignition i planned to use is a powerdynamo

[m in sc]

tough call to mod a new harness for that.  i wouldnt unless the old one was really rough.

[rd400greenhorn]

Yeah Its because the original did not look good

[Dvsrd]

tough call to mod a new harness for that.  i wouldnt unless the old one was really rough.

In any case, I would recommend cleaning all switches,  and ensure there is no resistance over the respective contacts. In my experience, the switches cause  at least as much grief as old wires and connectors. Also, using a Powerdynamo will allow you to remove maybe the weakest part of the stock harness, which is the 3 ac wires from the stock stat and it's connector block. I would recommend removing the 2 wires from coil negative (to the points) and all the wiring associated with the stock alternator,  rectifier and voltage regulator. The only wires going to the engene would be the Powerdynamo Harnes, plus the blue wires for the neutral switch. Pretty easy to do.

[rd400greenhorn]

what ignition? I mean, no harder than installing one on a stock bike. I think 78 and back was pretty much the same. its  a points model, right?

Haha iam glad to hear iam not the only one using that argument 😁👍

[rd400greenhorn]

tough call to mod a new harness for that.  i wouldnt unless the old one was really rough.

In any case, I would recommend cleaning all switches,  and ensure there is no resistance over the respective contacts. In my experience, the switches cause  at least as much grief as old wires and connectors. Also, using a Powerdynamo will allow you to remove maybe the weakest part of the stock harness, which is the 3 ac wires from the stock stat and it's connector block. I would recommend removing the 2 wires from coil negative (to the points) and all the wiring associated with the stock alternator,  rectifier and voltage regulator. The only wires going to the engene would be the Powerdynamo Harnes, plus the blue wires for the neutral switch. Pretty easy to do.

Awsome man, thank you! I Will try to clean old wiring up and see if i can figure it out, retape it and reuse it 👍