Glow plugs staying on (1 Viewer)

[Terry Boots]

hi, sorry to bother you all. I have a 1978 BJ43 that I just purchased recently from France.
Today I went for a drive and the glow plugs are staying energized and will not go off. Whether ignition is on or off, the coil on the dash is glowing. Usually I have to turn my key backwards and hold in order to energize the glow plugs. Now they are on while driving and even when I shut the key off.
Does this sound like welded shut relay contacts to you? Also is this located passenger side inside firewall?
Thank you and sorry to bug you.
Can I fix this by adding in a switch some where?

 

[roscoFJ73]

I think the problem might be just the light staying on rather than the glow plugs. They would burn out after a few minutes I think. Glow timing is a delicate balance of providing enough heat to get the engine running smooth and longevity of the plugs?
Have you attached a test lamp to the bus bar to see if they really are energised?

 

[Terry Boots]

Thanks
I should test this as well. I filed and cleaned the welded contacts in the relay

 

[PAToyota]

What did the contacts look like? A sticking relay will be fairly apparent.

 

[Terry Boots]

The issue turned out to be that the contacts inside of the relay were fusing together. I could see that there were small pieces of what looked to be welding slag in between the contacts. I took them apart by removing the spring and then filed them smooth with a fine file. I then used a small knife sharpening stone to get a nice polish back on the surface. Once back together all was fine.

 

[roscoFJ73]

Were the glow plugs actually on, or just the light?

 

[Terry Boots]

I am not sure. I need to look at the wiring diagram however I think that the glow plugs we probably on as well. When the contacts close in the relay there is more draw going through than just the coil on the dash I am sure. After I fixed the relay, the Cruiser fired right up though.

 

[PAToyota]

The relay would be controlling the glow plugs - no need for it to just control the light.

I'd check the glow plugs at this point. Most times they don't appreciate being on for more than a few moments at a time.

 

[Terry Boots]

Thanks, I will do as I suspect they are probably in ugly shape although seem to still work as it is firing up ok (for now)