Glow plug relay (1 Viewer)

[diesel_cruiser]

What doe the glow plug relay do besides offcourse providing the plugs with juice?

There are some extra wires there of wich I don't understand the function.

There are 6 wires coming in and out of the relay.

1 there is the WB wich is the ground

2 there is the WG wich comes from the ignition switch and activates the relay

3 there is the BY going out to the plugs

4 there is the B going to the resistor check light

5 there is another B going in wich is main power from the batteries

6 and 6 is a wire coming from the ignition switch. This is the wire that confuses me, what is the use of this wire?

Thanks

 

[diesel_cruiser]

close up

 

[hj60]

I can't really make out your scan too well, but my guess is it keeps the relay energized during cranking.
I'd need a better view of the schematic to tell you for sure.

 

[Perfect Obsession]

Dear Rookie,
Please, sign your post with truck and engine specs to receive help.

 

[beanz2]

I bet he has a BJ something or the other as the 2 glow plugs marked "for HJ" are crossed out.

Looks like the BW wire is to provide + signal to the relay while the ignition switch is on "start". Otherwise the glow plugs quit glowing while you're cranking...

Dave

 

[diesel_cruiser]

[quote author=Perfect Obsession link=board=21;threadid=14674;start=msg138177#msg138177 date=1081863881]
Dear Rookie,
Please, sign your post with truck and engine specs to receive help.
[/quote]



Dear sir, your avatar prevents me from making a smartass comeback comment!

 

[diesel_cruiser]

[quote author=beanz2 link=board=21;threadid=14674;start=msg138227#msg138227 date=1081869229]
I bet he has a BJ something or the other as the 2 glow plugs marked "for HJ" are crossed out.

Looks like the BW wire is to provide + signal to the relay while the ignition switch is on "start". Otherwise the glow plugs quit glowing while you're cranking...

Dave
[/quote]

Yes, I have a 1980 BJ, with the B engine, tought that it was clear from the diagram, sorry for that. Anyways, thanks for explaining what that wire is for.

 

[Perfect Obsession]

Bonjour,

By the way, I am really sorry for colateral psychotic issues derivative from my avatar.

Here is more serious point. IMHO, this relay is a big relay with timer and "relay" indicator light.

On the "cause" side, you have:
- power as per "B+ wire"
- an "shall" trigger as per BW "start wire"
- and a "may be" trigger as per WG "g wire"
On the "effect" side, you have:
- glow plugs as per BY "S wire"
- and a check light as per B "G wire"

IMHO, it's a relatively simple relay since you don't have temperature sensor, 2-staged timed glow plugs, ... "May be" trigger conditionates the pre and post starting starting and the "shall" trigger should be conditionated by temperature sensor (absent in your old model)

This relay replace (or can be replaced by) a humanoidal driven relay. Therefore, a simple button driven by a human being that trigger a strong relay (big current) that is powering glow plugs. Before starting and on cold start, the button is pushed to pre-heat. When starting, the button is still pushed if it's cold. And when it's started, the button is release (after a certain delay when cold).

In this case, the human being is only a conditional timer. In some other cases, it follows the beat

 

[beanz2]

Just . . . perfect


Dave