1987 HJ61 Pre-heating system not working

  • Thread starter ChangingMan
  • Start date
  • Watchers 2
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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

sved

Joined
Feb 24, 2012
Messages
738
Location
Sweden
Here you have the diagram.
20211127 133541

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

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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…
 
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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

B2DAFEA6 1B33 45FF 83F3 34662B53F703
 
sved

sved

Joined
Feb 24, 2012
Messages
738
Location
Sweden
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.
 
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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
 
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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!

254B14E2 2202 4429 9C11 E91267787A55
 
sved

sved

Joined
Feb 24, 2012
Messages
738
Location
Sweden
How about the connection on the glow screen ?? Disconnected ?
I mean this is just a NOT DONE hard wiring straight to the glowscreen. 🤔
 
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
The glow screen is connected and still seems to be ok (I checked for continuity).
 
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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…
 
C

ChangingMan

Joined
Feb 22, 2021
Messages
38
Location
Italy
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…

521A93D3 2A56 40F2 8FDA CC908E9FBDB5
 

Similar threads

96TrailSurfer
Replies
0
Views
140
96TrailSurfer
96TrailSurfer
KlickitatPhil
Replies
3
Views
204
Freewheel
Freewheel
4Ruster
Replies
3
Views
183
drenmaster
drenmaster

Users who are viewing this thread

Top Bottom