1987 HJ61 Pre-heating system not working (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

 

[sved]

Here you have the diagram.

2 relays which control the heater element on full or half glowing power.

 

[ChangingMan]

Here you have the diagram.
View attachment 2849285
2 relays which control the heater element on full or half glowing power.

Thanks Sved. Do you know if the two relays should look more or less the same?
I’m asking because I’ve had some info + pics from Australia and one of the two relays shown to me doesn’t match my 2nd one, plus they’re both 12v while I only have 1 x 24v that looks the same…

 

[ChangingMan]

Thanks Sved. Do you know if the two relays should look more or less the same?
I’m asking because I’ve had some info + pics from Australia and one of the two relays shown to me doesn’t match my 2nd one, plus they’re both 12v while I only have 1 x 24v that looks the same…

This is my 24v relay

 

[ChangingMan]

This is my 24v relay

View attachment 2849316

And this is my second “relay”

 

[ChangingMan]

And this is my second “relay”

View attachment 2849317

Whereas my new Aussie friend has this

 

[ChangingMan]

Whereas my new Aussie friend has this

View attachment 2849318

And this

 

[sved]

Your second relay is not a relay but a fusible link.
You should have 2 relays.
Both with same partnumber.
The one under the power outlet box is the correct one.
The other one should be mounted on the other side of the airbox on the innerfender.

 

[ChangingMan]

Your second relay is not a relay but a fusible link.
You should have 2 relays.
Both with same partnumber.
The one under the power outlet box is the correct one.
The other one should be mounted on the other side of the airbox on the innerfender.

Ok, thanks. I’ll go take another look tomorrow

 

[ChangingMan]

Your second relay is not a relay but a fusible link.
You should have 2 relays.
Both with same partnumber.
The one under the power outlet box is the correct one.
The other one should be mounted on the other side of the airbox on the innerfender.

So it looks like the previous owner has removed the 2nd relay!

 

[ChangingMan]

So it looks like the previous owner has removed the 2nd relay!

View attachment 2850292

I’m assuming these are the cables that are supposed to be on that relay - now just twisted together…

 

[sved]

How about the connection on the glow screen ?? Disconnected ?
I mean this is just a NOT DONE hard wiring straight to the glowscreen.

 

[ChangingMan]

The glow screen is connected and still seems to be ok (I checked for continuity).

 

[ChangingMan]

The glow screen is connected and still seems to be ok (I checked for continuity).

However my remaining relay isn’t working.

 

[ChangingMan]

However my remaining relay isn’t working.

When I first started investigating why my glow screen system wasn’t working, I started by checking the continuity of the glow element by following directions in my manuals (I have both Haynes & Gregory’s). After deciding that it was ok, I then checked the pre-heater timer and found it half-rusted out…

 

[ChangingMan]

When I first started investigating why my glow screen system wasn’t working, I started by checking the continuity of the glow element by following directions in my manuals (I have both Haynes & Gregory’s). After deciding that it was ok, I then checked the pre-heater timer and found it half-rusted out…

 

[ChangingMan]

View attachment 2850388

I guess water sat in it

 

[ChangingMan]

One of those two little relays was stuffed too…

 

[ChangingMan]

One of those two little relays was stuffed too…

View attachment 2850395

I’ve replaced the timer & relay, but now discover that missing timer from under the hood

 

[ChangingMan]

I’ve replaced the timer & relay, but now discover that missing timer from under the hood

Relay - not timer