HJ61 pre-heating system (1 Viewer)

[ChangingMan]

Hello everyone. I guess I’m really looking for Europeans, Kiwis and Canadians for help, although any Aussies living in Tassie or even colder parts of Victoria might be able to contribute.

My problem began with finding out that the pre-heating timer on my ‘87 HJ61 had rusted out. I guess the truck sat in water sometime in it’s past. I have replaced the timer but the system still won’t work. What I can’t work out is how many relays there are to supply the actual pre-heating element with power. I’m thinking there should be two - one for the pre-heat and another for the post-heat. Or is it just one relay + a resistor to reduce the power when in post-heat mode?

Any help greatly appreciated as I’m in about -5 centigrade now and the truck doesn’t like starting up in the morning! Thanks

 

[kevin in okinawa]

Hello everyone. I guess I’m really looking for Europeans, Kiwis and Canadians for help, although any Aussies living in Tassie or even colder parts of Victoria might be able to contribute.

My problem began with finding out that the pre-heating timer on my ‘87 HJ61 had rusted out. I guess the truck sat in water sometime in it’s past. I have replaced the timer but the system still won’t work. What I can’t work out is how many relays there are to supply the actual pre-heating element with power. I’m thinking there should be two - one for the pre-heat and another for the post-heat. Or is it just one relay + a resistor to reduce the power when in post-heat mode?

Any help greatly appreciated as I’m in about -5 centigrade now and the truck doesn’t like starting up in the morning! Thanks

Try posting in diesel/24v forum

 

[Samppahj]

Hello everyone. I guess I’m really looking for Europeans, Kiwis and Canadians for help, although any Aussies living in Tassie or even colder parts of Victoria might be able to contribute.

My problem began with finding out that the pre-heating timer on my ‘87 HJ61 had rusted out. I guess the truck sat in water sometime in it’s past. I have replaced the timer but the system still won’t work. What I can’t work out is how many relays there are to supply the actual pre-heating element with power. I’m thinking there should be two - one for the pre-heat and another for the post-heat. Or is it just one relay + a resistor to reduce the power when in post-heat mode?

Any help greatly appreciated as I’m in about -5 centigrade now and the truck doesn’t like starting up in the morning! Thanks

As per my knowledge a healthy 12H-T should start without problems even with no pre heating in much colder temperatures. It has two relays in the engine compartment.

Behind air cleaner.

In front of air cleaner.

 

[ChangingMan]

Thanks for the reply. Are these photos from a 60-series? I don’t seem to have the same relays behind the air cleaner as shown there.

 

[ChangingMan]

Thanks for the reply. Are these photos from a 60-series? I don’t seem to have the same relays behind the air cleaner as shown there.

 

[ChangingMan]

In front looks more similar though…

 

[Samppahj]

Pictures are from HJ60. Looked at parts diagrams it seemed to be the same. Looks like they are not the same.

 

[ChangingMan]

I wonder if it’s because your HJ60 has glow plugs whereas my 61 has the pre-heating element in the inlet manifold?

 

[ChangingMan]

I wonder if it’s because your HJ60 has glow plugs whereas my 61 has the pre-heating element in the inlet manifold?

I can only find 1 relay for the pre-heat system. It’s the gold/red thing in the upper right of the picture

 

[ChangingMan]

I can only find 1 relay for the pre-heat system. It’s the gold/red thing in the upper right of the picture

View attachment 2848569

More like in the middle actually, sorry . I discovered that it’s not working today, so that’s hopefully going to solve my problem