Glow plugs stuck on

[BiodieselBri]

I've got a 1980 BJ40 with a transplanted 3B. Yesterday the manual glow plugs decided to stay on while driving. I've got a switch that normally has a satisfying click when it engages and disengages, and one of those orange telltales that literally heat up. If I turn the engine off and put the key back into the run position I can turn the glow plugs on and off normally using the glow plug switch. A few seconds after I start the switch stops working and the glow plugs stay on - at least the orange telltale is on.

Any ideas?

 

[BiodieselBri]

Anyone?

 

[lostmarbles]

I've got a 1980 BJ40 with a transplanted 3B. Yesterday the manual glow plugs decided to stay on while driving. I've got a switch that normally has a satisfying click when it engages and disengages, and one of those orange telltales that literally heat up. If I turn the engine off and put the key back into the run position I can turn the glow plugs on and off normally using the glow plug switch. A few seconds after I start the switch stops working and the glow plugs stay on - at least the orange telltale is on.

Any ideas?

If it is like mine, then the "satifying click" will be coming from the "glow plug relay" which I seem to remember is located in the passenger footwell area on my right-hand-drive vehicle. This relay clicks in whenever I turn my ignition key backwards to the "glow position".
If my glow plug relay were to "click in" when my ignition key was in the "run position" then my ignition switch would be faulty.
However I suspect your wagon is wired differently because you talk of some sort of "glow plug switch" that is apparently separate from the ignition switch. (Your symptoms are likely to be affected by how this switch has been connected up. Perhaps some sort of automatic timer is present and connected up incorrectly or become faulty.)
The 3B is different to my B engine and uses a different glow plug set-up. Who knows how much of your system resembles mine after this engine transplant????)
PS. It is normal for the "glow to remain" (but gradually die away) once the engine has started. Good luck.

 

[brownbear]

pull the switch and take a mulitmeter set for ohms, turn the switch off and see that it does not have continuity(no numbers except inf) turn it on, you should have 0 or .3 ish. If you do the switch is fine.


find the relay, unplug the connector. Put power to one small wire and ground(-) to the other. The relays should thunk/click. And the main big wire terminals should read 0 or .3 ish. Take away power from the little wires and there should be no continuity thru the relay.

if it fails go to napa and buy a new relay. See Peterdouglas thread about glowplugs for the part number.

 

[brownbear]

oh and you should have a push button for switch not a toggle switch. Large cutler hammer push button type. The kind used as a starter switch on equipment.

 

[BiodieselBri]

Thanks for the tips - I'll bust out the multimeter and do some checking. My cruiser used to have a B in it but with the 3B transplant I retained the old glow button. I've never tried doing the backwards glow but I doubt it would work, I only get glow when I press the button. (You're right brownbear, it isn't a switch)

 

[Scoot Jockey]

I'm not sure if this translates to your 3b, but my 2h did the same thing when the thermosensor for the glow system came unplugged. Rotten deal since it ruined about $150 worth of glow plugs. I guess it could also happen if the sensor goes bad.

 

[brownbear]

if the sensor is bad, every time you glow the plugs are on for maximum amount of time, with no regard to the coolant temp.

The plugs will age quicker, but they should handle it fine. My guess is yours were tired anyhow. Some guys do the sensor disconnect to get more glow in the cold.


I like a push button you control. Not a timer designed for Tokyo winters

 

[BiodieselBri]

Turns out the problem with my glow plug relay was fixed by unscrewing the relay cover and cleaning the relay contacts. Could have been some dust or maybe a bug got in there. Anyway, the relay works fine now. I wasn't excited about finding a new one, they seem quite hard to track down.

 

[KOOTENAY KRUZER]

Turns out the problem with my glow plug relay was fixed by unscrewing the relay cover and cleaning the relay contacts. Could have been some dust or maybe a bug got in there. Anyway, the relay works fine now. I wasn't excited about finding a new one, they seem quite hard to track down.

I was going to suggest this, I have a 3B transplanted into a '79 BJ40 using the original wiring system that was for the B engine.

The glow plugs on mine are manual, they can be operated by turning the key backwards or by holding a momentary contact rocker switch on the dashboard. They are also on whenever the key is in the start position.

My relay contacts were pitted and sticking, I polished them with crocus cloth and have not had a problem since.