Location Glow relay 1HD-T (3 Viewers)

[toadshade]

2 questions if anyone can help. I am trying to diagnose some cold start issues and so I am replacing my glow relay. If it is in the standard HDJ80 FSM, I can't find it I don't have the engine repair FSM yet so I wanted to see if anyone could tell me where it is. I can't believe this honker of a relay isn't clearly visible, but I can't find it. There is also a chance I have the wrong part. Another question is identifying a part on one battery (the battery connected to the alternator, in my case, the passenger side LHD). There is a ~1-2" black cube I have always wondered about that just has "glow" stamped on it connected to the battery. Taking the top off, it just looks like no more than a terminal. Didn't appear to have a resistor or look like a relay, but maybe the new relay I have is the wrong part.

 

[tlaporte]

There is a ~1-2" black cube I have always wondered about that just has "glow" stamped on it connected to the battery. Taking the top off, it just looks like no more than a terminal. Didn't appear to have a resistor or look like a relay, but maybe the new relay I have is the wrong part.

I’m not familiar with 80-series diesels, but the box you’re describing sounds like the small junction where the fusible link is connected. Since the fusible link is intentionally designed to be the sacrificial link in the electrical system it’s set up to be easily replaced.

 

[CaptBeardilocks]

AFAIK there are 2 glow "relays" on the 1HDT. The first one is the one you found, looks like a junction with a cover on it. The second I believe looks like a over large "ice-cube" relay of old. 3x2x1" give or take? And it is located (on my RHD HDJ80) in the "passenger" (left side from driver's perspective) fender. I have absolutely no idea if it is on the same or opposite side on the LHD trucks. But I would guess that it is on the same side as the GP relay that you did find.

I can get you a pic in a couple of hours here. But it is literally IN the fender, through one of the fist sized holes between the wheel well and the firewall. That's why you can't find it.

 

[CaptBeardilocks]

Until I can get a photo:
(FYI: This is the fiche from a LHD VIN 1HDT 5spd. But that doesn't mean yours isn't on the other side.)

 

[toadshade]

That was a lot of help. You guys rock thanks!

 

[CaptBeardilocks]

With fender off obviously

 

[CaptBeardilocks]

From my hazy memory I think one of the two relays *may* be NLA. Not positive. But I’ve also read other threads on here where one relay is considered not necessary and is frequently deleted from the system. You’d have to research that a bit.

I’m currently on the fence about what I’m leaving in & taking out on my swap as far the factory system vs Wilson switch and what you keep in line with the Wilson etc. But no where close to any conclusions. Lol.

 

[toadshade]

This is the relay I just got. It was readily available. So if there is another, other than the fusible link junction, I am not aware of it.

 

[toadshade]

Never thanked you for that photo CaptBeardilocks. That helped a lot. I am reviving this a little since I am just replacing that relay today (I hope) I have been looking for a post regarding the two relays and which one might not be necessary. I cannot find any info on what each one does and why one is not needed. I found a loose wire going to the glow relay at my battery. I fixed it and my problem went away until yesterday. So I am after the relay again. It must have been a slow burn that got a little more juice when I upped the amperage for a couple weeks. But I hope I have the right relay. The one pictured above. I have found the other one though so it is still on the market. Wish I had them both so I could do it at the same time. It looks like it is going to be as fun as replacing the antenna mechanism (that I have since ditched for a dash antenna).

 

[toadshade]

Oh well, that relay wasn't the issue. Can only imagine I got the one that for whatever freaking reason, doesn't matter. Back to the drawing board. Found out today that my truck is a "snow version" which has a fuel heater. That is on the list although it is nowhere near cold enough for that to be an issue today (55 degrees). And you weren't kidding. That 28610 is not available anywhere.

 

[CaptBeardilocks]

Mine also has the fuel heater. I’ll likely not plug in the fuel heater, I can’t imagine I’ll need it. I’m curious what would make the “snow version” different. Especially in the glow system. So I’m following this closely.

For all the complication of the system, I’m definitely going to be looking into a Wilson Switch of some kind.

 

[toadshade]

I was just checking that out. Didn't look too closely at it yet, but it looks like something for a pre-glow setup, not the positive pressure 1HDT. Not to say it wouldn't work, but if it times out, then does the normal system back it up when necessary? Unfortunately, my knowledge of the glow system is limited. I hear two schools of thought that say the glow system is only there for starting and others that say it is helping combustion at all times. Don't know if that is the case with all diesels or the 1HDT. So therefore, is the Wilson switch helping or hurting during normal operation and not just starting? I am sure this is all documented all over the place somewhere.

 

[CaptBeardilocks]

I’m not aware of the 1HDT glow system continuing to help with combustion. But there’s a LOT that I’m not aware of. My understanding was that have a timer in the ~15-25sec range (vaguely) depending on temp? I’m pretty sure I’ve seen quite a few 1HDTs with Wilson Switch’s.

I’ve read (but can’t back it up right now) that 1HDT doesn’t need much glow until pretty cold temps. Maybe someone else can chime in with better info.

 

[toadshade]

Just a follow up. Turns out I bet I have air in my line. Everything I am reading about is pointing to my fuel filter for an air leak. Found one at the sensor on top of the housing. But I had a question for you. About that photo you sent. The relay you have in your hand. Where was that located? I replaced the one in the fender but it looks like the other one in your photo should be obvious. But I don't see it. I see a place where it could have been mounted so maybe that is the one that is not really needed and was at one time removed from my truck before I got it. I really need to find out more about that.

 

[CaptBeardilocks]

I can't remember exactly where that was removed from. My memory is that it was mounted under something in the region circled below, so I could be wrong. But it's maybe not at all obvious on first look. And I believe the big wire on it either goes straight to the battery or to the 4-wire junction block pictured. I can check where the wiring goes in a minute here so you can at least trace it.

 

[toadshade]

OK. Over the 24V block. I will have to take a look. Thanks

 

[CaptBeardilocks]

Here ls where it sits. Not a lot left in there for reference. Lol. To the right of it in the photo is where the fuse block is on the RHD version. It’s right under that stuff circled in the last photo.

 

[toadshade]

Huh. I do not have one of those. How odd. I can't wait to find out a little more about that. Turned out to be an air leak in my filter anyway. Pretty sure at least. I re-ringed my fuel heater on the pump housing and truck seems to be running well. Still need a new housing but I am back on the road. Just saying for posterity sake. I appreciate the photos and the help. Just for S&G I checked my whole engine compartment since mine is a LHD, but it isn't under my air filter lol.

 

[CaptBeardilocks]

Glad I could help. And now I know if I have an air issue to look at my fuel heater as a suspect. Cheers.

 

[toadshade]

Yep. Got most of my info on a thread called "Snow Version"