Glow Relay Wiring BJ40 2.9D 1977 (1 Viewer)

[RemcoSeegers]

Hi all, in all schemes I find the wiring like this (I added wire colors)

My car is 4 cylinder but that should make any difference, however, the original connection in my car is like this:

Any ideas why it is different and what is the purpose to change like this? It is weird because the thick black cable somewhere half way in the wires just connects to BW... Any ideas?

 

[ToyotaMatt]

Hi all, in all schemes I find the wiring like this (I added wire colors)
View attachment 3415033
My car is 4 cylinder but that should make any difference, however, the original connection in my car is like this:

View attachment 3415034

Any ideas why it is different and what is the purpose to change like this? It is weird because the thick black cable somewhere half way in the wires just connects to BW... Any ideas?

.

what is the problem or the issue ?

it looks like originally current needed to flow through the filament of the bulb , the bottom diagram includes a splice point or perhaps now it is a form of a parallel circuit ?


if the glow plug controller bulb filament blows , then the current path is severed ...

 

[RemcoSeegers]

It is perhaps not a problem but is weird. I have the whole harness taken apart as it was messed up and I try to rebuild it. The issue is that I can't find a 100% matching diagram, it is a puzzle although I am getting to the end. The strange thing was that out of the glow relay a black wire comes out that went nowhere while in order to several (none 100% matching) diagrams it should lead to the glow controller. I found that just somewhere halfway the harness it connects to the lead that goes to the controller and I thought it could have been another trick of the previous owner. But, loking to how it connects, it seems factory. It would have been easier to just bridge output G with S on the relay and save a lot of thick wire in the harness and a connection made halfway...

 

[45Dougal]

The glow controller is just a coil of wire that gets hot when you leave the key in the glow position for too long.
Its resistance increases when hot and protects your plugs from getting burnt.

While cranking, your battery voltage drops and so you don't need the extra protection of the controller.
It maybe that on the 24V 4 cylinder engines, you still needed protection while cranking.

I'd double check that your glow plugs are the correct voltage (good luck confirming that), and that your glow controller is the correct one (there are two versions - one uses thicker wire).

Either way it's unlikely to cause you a problem unless you're in the Arctic