HELP! HJ45 Glow Plug Controller heating too fast (1 Viewer)

[brownbear]

With shorts, they draw a lot of amps. As you are aware. The contacts in a relay can get welded. Even though you hear a click doesn't mean the solenoid (relay) is working. It just means the actuator is moving.

Put a mulitimeter set to ohms across the relay main wire (big wire) posts. You have to disconnect the wiring to do this otherwise you get system loops etc. With no power you should have no continuity. If you see continuity, it's welded. Keep in mind some relays are opposite, being normally closed. Not for a glow relay though.

If you cannot figure it out, one step will be to replace the glow plugs with 10.5 ones. Then add a relay and wire your switch for a purely manual set up. Cutting out the controller thing, and all the wires.

 

[athensrep]

Just want to be sure I understand this. When you turn on the key to the run position you get 12V at the glow plug bus bar? If you press the glow plug momentary switch it drops to roughly 8.5v?

You should only have voltage on the bus bar when you are pressing the glow switch.

I'm sorry that I wasn't clear…with power on and when I hit the glow plug momentary switch, I get around 2.75-3v (before I have to let it go - around 3 seconds).

Testing the controller when momentary switch is depressed:
Green/Blk wire to ground - approx. 3.5v
Blk wire to ground - approx. 3.5v
Green/Blk to Blk wire - approx. 5.5v

I have not tested the relay yet, but could do that a bit later today. After this "work" thing is done.

 

[bj40green]

I'm sorry that I wasn't clear…with power on and when I hit the glow plug momentary switch, I get around 2.75-3v (before I have to let it go - around 3 seconds).

Testing the controller when momentary switch is depressed:
Green/Blk wire to ground - approx. 3.5v
Blk wire to ground - approx. 3.5v
Green/Blk to Blk wire - approx. 5.5v

I have not tested the relay yet, but could do that a bit later today. After this "work" thing is done.

???? Where do you see a Green/Black wire????

Rudi

 

[athensrep]

I seriously need more sleep…I understand if you give up on me!

What I MEANT to say was the Yellow and Black wire connecting to the Glow Plug Controller was tested (forget Green and black - I don't know where I got that from).

 

[bj40green]

I don't give up on you, don't worry.
Those figures don't make sense. You have short or a very (too) low resistance down the line. You also mentioned that you have 2.8V on the busbar.
Disconnect the Black/Yellow wire from the busbar.
Depress the glow button. Does the controller still glow?
Meassure the voltage on the busbar wire (stil disconnected) when you hit the glow button.
Report these values please. My theory is growing.

I'm off for a few hours so, hasta mas tarde (see you later).

Rudi

 

[athensrep]

Ok now. I just disconnected the black/yellow from the busbar and depressed the glow button - no nuclear glow.

I also tried both wires while depressing (still with the disconnected busbar) - both sides are at 12v.

Hmmm. Wait a minute. Could it be that although my EDIC cable is not directly touching the busbar or Glow Plugs, it's still grounding out due to it touching the fuel rail??? Surely not…

 

[RufusTheDufus]

What method did you use to test all of your 10.5v glow plugs?

 

[bj40green]

Ok now. I just disconnected the black/yellow from the busbar and depressed the glow button - no nuclear glow.

I also tried both wires while depressing (still with the disconnected busbar) - both sides are at 12v.

Hmmm. Wait a minute. Could it be that although my EDIC cable is not directly touching the busbar or Glow Plugs, it's still grounding out due to it touching the fuel rail??? Surely not…

So the problem is in the busbar and/or glow plugs. I have the feeling that one of the plugs has too low resistance (almost a short) or something is still shortening out the busbar. I don't know the resolution/sensivity of your ohm meter but I suggest that you remove the busbar and do an ohm test on all 6 plugs and try to find the one with the lowest value.

We're getting closer.

Rudi

 

[athensrep]

Just to be certain, I just took the glow plugs out and tested them all with a fresh 12v car battery. Each plug glowed nice and red hot within 15 seconds. All are working fine. Really scratching my head...

I did learn that my 10 seconds of glowing may not be sufficient as it's taking 15 to really get them started on a battery with 12.5v - I suppose I have good compression then...at least I got that going for me.

 

[bj40green]

To sum it up with the busbar disconnected:
√ The controller doesn't lit up any more.
√ You have 12V on both sides of the controller
√ You have 12V on the wire to the busbar
All glow plugs are visual fine but you don't know if one of them is pulling excessive current.

What is the DC amp range on your multi meter?

Rudi

 

[RufusTheDufus]

What is the NGK part number for your 10.5V plugs? I'd like to try to look up the specs.

 

[bj40green]

What is the NGK part number for your 10.5V plugs? I'd like to try to look up the specs.

He's using the wrong plugs. He should have 8.5V plugs in combination with the glow controller.

This is a part of my glow plugs research.



Rudi

 

[lostmarbles]

I wonder what the story is with these 12V HJ45 models..

Jespervangfalkenberg appears to be having exactly the same problem with his glow controller heating up much faster than it should too. See this thread:
https://forum.ih8mud.com/diesel-tech-24-volts-systems/791305-glowsystem-hj45-12volt-advice-2.html

I'd have expected those 10.5V plugs (in place of the specified 8.5V ones) to cause this glow controller not to glow at all but yet it actually glows too fast!!!!

All I can think of here is that perhaps whoever is making these new replacement 12V HJ45 glow controllers for Toyota has stuffed up their recipe for the coil/element length/diameter needed to match the correct spec plugs (and to match SIX of them) ...

 

[athensrep]

Gents,

I had to take a day off from the mustard today, but should be back at it tomorrow. Thanks again for the help on this.

Mark

 

[athensrep]

To sum it up with the busbar disconnected:
√ The controller doesn't lit up any more.
√ You have 12V on both sides of the controller
√ You have 12V on the wire to the busbar
All glow plugs are visual fine but you don't know if one of them is pulling excessive current.

What is the DC amp range on your multi meter?

Rudi

With a disconnected busbar, all above statements are true.

My multimeter DC amp range is 200m - 100.

Any thoughts? New plugs? New wiring setup? New brand of beer?

 

[bj40green]

There is so much bubbling in my mind.....
Going back in time:

You glow 15 seconds, controller never lits up, engine starts.
Comment: with 10.5V plugs I don't expect the controller to lit up. The controller is designed for six 8.5V plugs which draw 9 or 10 Amps each so 54 - 60 Amps in total.
However you have six NGK 10.5V plugs which draw 7 Amps each so 42 Amps in total. That's some 20% less so it will not lit up.

You add the pull-to-kill-the-engine cable which touches the glow plugs and you fry the controller.

You removed that cable from the glow stuff and replaced the controller with part # 28550-47021.
From now on you're in trouble but why?

Or..... there is a point of super low resistance (drawing a lot of current) somewhere in the busbar area...
or..... the new controller is out of spec. Maybe for a 24V system but wrongly stamped at the factory.

It must be in the busbar area because you disconnected the busbar and now all the voltage make sense.

Back to the present;
Are you willing to test each plug with the Amp meter in series to check how much current each plug draws?

Do you still have the first controller? Can you post a pic from the old one and the new one. I like to see the inside (or what's left of it) compared to the new one.

Rudi

 

[athensrep]

Just checked all plugs and I'm getting .2 ohms for each.

Here's a pic of the toasted controller...
This one was a 28550.

 

[RufusTheDufus]

.2 ohms seems low. I would have expected .5 to .7 ohms.

 

[bj40green]

Thanks for the picture but I was hoping to see a picture like this.
This is a pic of my OEM controller (left) for my BJ40 and the one on the right is the one they sold me as the replacement. NOT!


From what I can see is that your old one is made of much thicker wire and less winding's than your new one. Strange.....

The cold ohm value of those plugs are not very reliable because OHM meters are not exact below 1 ohm.
Much more interesting is how much amps the plugs draw after 10 seconds.
That way we can see if they are all in spec. or that one draws excessive current.
The spec for an 10.5V plug is around 7Amps

Rudi

BTW: All controllers start with 28550-

 

[athensrep]

I'm afraid the controller will pop again if I glow for 10 seconds. It gets Chernobyl hot at 3 seconds.

I looked at the plugs more closely this evening - upon fine tooth combing them, I noticed one of them has a cracked insulator. I'm not sure how much bearing that would have, but worth a mention. I've read on some VW diesel forums that it's a good idea to shrink wrap busbars. Mine is showing its age with some of the insulation flaking off. Not bad, I figured its good practice.

I figure new plugs are in order anyhow (8.5) and I may even fabricate a new busbar for safe measure.