Frying Glow Plugs - my wilson switch questions (1 Viewer)

[DillonOnTheCoast]

I have a Central American '84 HJ60, 12v 2H. It originally had a superglow system but it has been modified to fixed delay with a 20s timer. I have a #28610-570 glow plug relay 2 connectors (one round, one rectangle).

When I turn the key partway, the orange flow light comes on and I get 10.5v at the glow plug bus bar for ~20s .

Recently it has started frying glow plugs. 12 plugs in 6 weeks. Not good. I believe that the glow plugs are staying on when they shouldn't. I haven't been able to catch them in the act but that's the only explanation that makes sense. The glow light never comes on when I'm driving around.

I'm not sure if I have a short in the wiring somewhere that is tripping the relay or if there are some superglow remnants causing me trouble.

Since I am not sure if I can trust the wiring I am considering wiring the whole thing up myself rather than tapping into the factory wiring like most wilson switches.

This would mean:
1) momentary switch on the dash tapped off the fuse box
2) 18g wire through the firewall to a relay
3) 10-12g wire from the battery to the relay
4) 10-12g wire from the relay to the bus bar

Good plan? Any recommendations on relays? I wonder if I could use my stock one.

 

[bj40green]

Sounds good to me.
My choice would be AWG10 because you have 6 glowplugs (10.5V) drawing ± 10Amps each so 60Amps in total.
You can use the stock relay but do a check first. Make sure it's not the culprit of your present problem.
Open it up and have a look at the contacts. Clean / polish to shiny bright copper.
Tip: Use a fusible link from your battery to your relay.
Good luck,

Rudi

 

[DillonOnTheCoast]

Thanks. Good point on the fusible link.

To save myself some work, perhaps I'll reuse my relay and the wiring from the battery to the relay and the relay to the bus bar.

I think this makes sense because the issue is likely to be in the ignition switch or the timer (which are still bypassed) or the relay which I can clean or replace. I have a spare 28610-570 relay on-hand.

Good?

That just leaves me with switching the relay itself. I've been reading wiring diagrams and of course nothing matches what I have. I need to determine which of the pins on the glow plug relay correspond to earth/ground and which pin should get 12v from my wilson switch.

Choices:

• Round connector - Fat Green (to glow plugs or battery?)
• Round connector - Fat Black (to glow plugs or battery?)
• Rectangle connector - ~AWT18 white w/black stripe
• Rectangle connector - ~AWT18 black
• Rectangle connector - ~AWT16 black w/white stripe

This thread is a wealth of information but nothing matches my relay: https://forum.ih8mud.com/diesel-tec...ng-bj40-bj42-hj42-glow-relay-manual-glow.html

 

[bj40green]

Just a suggestion.....
Leave the old set up for what it is.
Put the (old or new) glow relay on the fender.
Wire from Bat to relay and from relay to busbar. It's only a few feet of AWG10. Done!

Rudi

 

[DillonOnTheCoast]

I could do that but I doubt the wiring between battery & relay and between relay & bus bar are frying the plugs.

Isn't it more likely to be in the ignition switch, the wiring from the ignition switch to the relay or the relay itself?

I'm pretty convinced it isn't over-voltage since I have 10.5v plugs on a 12v system so something must be energizing the plugs when they shouldn't be on.

 

[bj40green]

OK, so you want to do some fault finding?
I'm pretty sure that a relay is activated while it should be in the off position. It can be the timer relay or the glow relay or... the system/circuit that activates them.
From your first posting I read that you have a "fixed delay" or a "super glow" glow system.
The link you referred to is about the glow relay in BJ's with a "manual" glow system, with or without an EDIC system.
The info you're looking for is in this thread: https://forum.ih8mud.com/diesel-tec...-should-i-running-b-2b-3b-h-2h-diesels-2.html and the diagrams are in posting #39 and later.
Here you can also see the wire colors you're looking for.

Hope this helps.

Rudi

 

[DillonOnTheCoast]

It was originally superglow but sometime in its history it was converted to fixed delay. I want to convert it to fully manual.

As for fault-finding ... whatever is energizing the plugs is doing so intermittently. Rather than spend time hunting it down I think I'd rather just bypass the whole thing.

Thanks for the link. Those diagrams were close but they are for a different relay and none of the wire colors match.

However - I just hooked it up to a bunch of test leads and I think I figured it out.

Choices:

• Round connector - Fat Green - hot when relay is on
• Round connector - Fat Black - connected to battery
• Rectangle connector - ~AWT18 white w/black stripe - turns on relay when hot
• Rectangle connector - ~AWT18 black - ground
• Rectangle connector - ~AWT16 black w/white stripe - no idea.

I'll run a small gauge wire from the fuse box (ignition switched) to a momentary switch and then to white w/black stripe on the relay, ground black, and reuse the fat wires in my harness that carry all the current.

I'm definitely not doing this for fun so if anybody has a better idea or can convince me I'm wasting my time I am all ears.

 

[bj40green]

Here are my thoughts.
If you use parts of the old harness you run the risk that the "intermittent problem" is still in the harness.
If you start "clean" with 2 new fat wires, the new momentary switch and the old glow relay (which you have checked) on the fender or firewall you've eliminated totally the old circuit and the possible problems from the past.

Rudi

 

[orangefj45]

Hey dillon. Did you get the pics and part numbers I texted you yesterday afternoon?

Hth

Georg

 

[DillonOnTheCoast]

Negatory George - I have downgraded to a dumb phone and it doesn't hande attachments well. I did get a zombie txt with no content - that must have been from you.

 

[Jan-78FJ40]

It was originally superglow but sometime in its history it was converted to fixed delay. I want to convert it to fully manual.

As for fault-finding ... whatever is energizing the plugs is doing so intermittently. Rather than spend time hunting it down I think I'd rather just bypass the whole thing.

Thanks for the link. Those diagrams were close but they are for a different relay and none of the wire colors match.

However - I just hooked it up to a bunch of test leads and I think I figured it out.

Choices:

• Round connector - Fat Green - hot when relay is on
• Round connector - Fat Black - connected to battery
• Rectangle connector - ~AWT18 white w/black stripe - turns on relay when hot
• Rectangle connector - ~AWT18 black - ground
• Rectangle connector - ~AWT16 black w/white stripe - no idea.

I'll run a small gauge wire from the fuse box (ignition switched) to a momentary switch and then to white w/black stripe on the relay, ground black, and reuse the fat wires in my harness that carry all the current.

I'm definitely not doing this for fun so if anybody has a better idea or can convince me I'm wasting my time I am all ears.

That sounds fine. There should not be anything between the thick wire and the glow plug bar.

The relays are really extremely simple. If you are afraid that the relay may be faulty, just test it by applying voltage to the thin white black. that should gibe you continuity between the thick wires and you should hear an audible click.

To test whether the intermittent current could come from the relay, carefully open it up by bending the little tabs open and pulling it apart. inside you will see a spring that keeps the connection open when no current is engaged. If this all looks clean and the spring is not rusted out, there should not be accidental intermittent current going through the relay.

cheers,
jan

 

[Tapage]

1. HJ60 using 10.5 GP stay no longer than 12S

2. IMOP 20S are a lot !

3. depending on your engine condition and environment temp you should be able to start your 2H withing 6S glowing ( or not at all )

4. Did you ever test your V at the bush bar ..?

 

[DillonOnTheCoast]

Yup - voltage is as expected - 10.5v when the plugs are good. The connection goes directly from the relay to the bus bar with no resistors in between.

The timer is ~20s, maybe its 15s. I've never measured it but I don't always let it go all the way before starting.

 

[wooleyfj62]

Sorry yet another old thread but im trying to do a 2ht conversion atm and am trying to manually wire my glow plugs. Ill either use a full new harness, 200amp relay, or try and use the factory relay and wiring to the plugs. How would inwire the resistors or do i just by pass em

 

[brownbear]

It's the duration on the timer that is frying the plugs IMOP too. I only glow for ten seconds manually.

It's very hard to figure out how someone previously wired it using the delay timer and such. I would seriously try to go fresh and remove the old stuff. Manual glow plugs suit our cruisers, nice and simple.

I always under glow, like I said ten seconds, then crank it and it fires. Then I hold the glow button to keep it running smoothly for a tad more.

 

[Justcruzin]

Hey Brownbear!

Is your engine 12 or 24V?

If 12V, what voltage glow plugs do you use? 12/10.5, 12/8.5, 12/6 or even 24V ??

Reason I'm asking is i just switched from a super glow system that used 6V plugs on a 12V truck to a fully manual, momentary switch system
and that, of course, fried my 6V glow plugs.

Thanks for your reply.