2LTE Glow system (1 Viewer)

[Postoy]

Hey All,
I have been having an issue with my glow system over the past year. The previous owner of my truck installed a "wilson switch". The truck will not start (summer or winter) without this switch cycled for at least 10-15 seconds. Well recently this switch has just stopped working all together. Now I have to physically jump 12 volts from the battery to the glow rail to get the truck running. (Glow plugs are new)

I am thinking about bypassing the stock system all together and wiring in a a relay that sends 12 volts through individual fuses to each glow plug. The plugs in my truck are 11v(?) Does anyone see any issue with this?

 

[GTSSportCoupe]

I'd recommend using the factory relays that are already there if they are ok. They are able to handle the high current and the wiring etc. is already there. You should just double check what the previous owner actually did and make sure they did not just make things worse.

Here is the actual schematic for the LJ78 engine (Includes glow system). I've marked the two relays for you. The Main Relay puts 11V to the glow plugs, the Sub Relay puts 6V I think (it uses the resistor in the intake manifold to drop the voltage. The Sub Relay is sort of an 'after glow' thing. Both are controlled directly by the main engine computer. I have the pinout for that also if you want to know what wires to tap into.

Basically, I think if you put a momentary contact switch on the activation wire going to the main glow relay, you could use that to manually glow the truck. Cut the wire, and put one side of the switch on the wire going to the glow relay and the other side of the switch to 12V (fused). Maybe that is what the previous owner did?

You could also wire a double throw momentary so when the switch is not being pressed, it reconnects the ECU wire. This way if no one presses the switch, then the ECU will still do it's thing....

If your glow relays are shot, you can still use the factory wiring, just replace the relay with a junkyard one from a Surf/Prado, or an aftermarket new one. Just a matter of testing it all. Let me know if you need ideas.

 

[Postoy]

Thank you GTS, as always very helpful! Ill have to fish the wires that are going to the switch to see whats going on.

 

[GTSSportCoupe]

Thank you GTS, as always very helpful! Ill have to fish the wires that are going to the switch to see whats going on.

If you get stuck finding the right (factory) wires, let me know, I'll find them on my truck and take pictures.

Also, I have translated everything in that schematic, so if you need more info I'll take the time to put the English on them for you.

Schematics for the whole Japanese version truck are uploaded; links here: Found Japanese 1990-1995 70 series wiring manuals!

 

[bj40green]

If the PO installed a Wison switch set up and it worked, why don't you trace back which part is not working?
It's a momentary switch and a relay and some wires in between.

Rudi