Reinstalling air pre-heater matrix - help please

[SteveS]

The previous owner of my truck removed the wire loom and solenoid that connects the air heating matrix to the battery when air is pre-heated on cold morning (similar function to glow plugs). The attached two sketches give the part numbers and approximate locations. The solenoid looks to be mounted behind the air filter box, and the matrix is on the air intake.

Could somebody please take a photo of the wire loom route so that I can re-instate it in its original position, particularly as it bridges the gap between the chassis/bay and the engine as this is where the rocking action of the engine is most likely to be critical to the loom reliability. The loom number is 82124-60080, the solenoid is 28610-17090

Even though I have split the batteries, I see no reason why the heater matrix cannot be connected back to one of the batteries (in this case it will be the leisure battery) - if anyone has any thoughts on that then I would be happy to receive them

 

[uHu]

Re-installing the heater is doing a big, huge disfavour to you, your vehicle, your batteries, the alternator and the drive belts.
There is absolutely no need for this heater other than for reducing emissions during the first 90 sec of a cold start, and how much (or little) the emissions are reduced is questionable. The power consumption of this gadget is enormous, and it certainly reduces the life span of the alternator, the battery and the drive belts.
I have never heard of any hdj100 having starting problems in the cold, but it is possible that if colder than minus 30 C, it would start easier with the heater grid in place.
Another thing the grid does, is to reduce the air flow, which could increase your fuel consumption (or reduce power) a little.

Anyhow, if you still want it, I'll be more than happy to go outside a snap a few pix. I might even have some ready, from documenting everything before taking my cruiser apart. Mine is WHD tho' (wrong hand drive)
And yes, the leisure battery could be a very good choice, depending on what charging setup you have. If you have a DC to DC charger, the Amp rating of the charger decides how fast the battery will recharge, and how much load it puts on the alternator. It could in fact work better than the original system. But, as I said, spend your time on something good instead.

 

[Towpack]

I'm not overly familiar with the setup on the 100 series but, going on the assumption that the intake heater on the 100 is the same or similar to the 80 I refute the claim that it is bad for the batteries, alternator and drive belts. I've used mine for virtually every cold start since I bought the 80 over 11 years ago. When the OEM relay packed up several years ago I replaced it with a motorcycle starter solenoid (didn't fancy paying £180>) and it still works fine. The batteries on the LC when I bought it lasted over 9 years. The intake heater is a factory fitted OEM starting system so the electrics will handle it with ease. IMO.

 

[SteveS]

Well in our travels around the arctic wastes of Canada and Alaska this year it dawned on me that this gadget does do something useful. We weren't particularly cold and at worst only -10C. So the truck did start every time it is true but the exhaust was oily/diesel and the engine lumpy for say 10secs before things started to warm up. Not a huge problem I guess. My truck is very clean on the exhaust usually. The effects seem to start in a small way at 5C and get worse as the temperature drops - my guess is that it would become a real problem at -20 or -30C. I'm with the school of thought that says that as it is OEM then it should be ok. Plus, my split charger once engine started will only allow the alternator to charge the main starter battery for the first 30secs, before linking the two batteries - this feels like it would stagger the alternator load in those early seconds. The relay only operates the matrix on cold mornings - if I were concerned I could easily keep the wire disconnected for the most part and just connect if the engine failed to start/below zero say. On the flip side the heater current would still be on the uncharging leisure battery for 30 secs which could be interesting for that battery. Also IIRC the later 100s have a beefed up alternator output and is in any case current limited - presumably with this feature in mind??

What is the amperage/Watts of the heater matrix? This would help me gauge it. The cables look like they could handle 20-30A without too much bother

A photo would be useful - thx

 

[Towpack]

The heater on the 80 pulls around 40-45A. I have one of the 80's with a 24v starter so the initial heater load comes off just one (driver's side) battery until the engine fires, then the load is shared by both as they're switched back into parallel by the changeover relay. When I eventually replaced the batteries I had both individually drop tested and while there was a difference between the two is wasn't huge so, personally, I don't think regular use of the heater affects battery life to any significant degree. No idea if the 100 has a similar setup.

 

[uHu]

I'll find some pics.
comments:
The heater grid comes on if the coolant temp is under +40 C, and stays on for 90 secs, or shorter is coolant temp reaches 40 C.
In my non-scientific test, the batteries lasted 3 years with the grid connected (got new ones on warranty) and the same type of batteries lasted 5.5 yrs with the grid disconnected.
The heater grid is not fused, up to 7/2002 production. From 8/2002 it goes through fusible link Main 2.

 

[uHu]

Here's from my 2004:

 

[uHu]

And from my 2000: Does this help?

 

[SteveS]

Thanks for the photos uHu - much appreciated. I will connect up and report back. I plan to connect direct to the battery on the offside as I don't have a link cable across to the fusible links. This should be fine as the EWD shows direct to battery terminal for 1HD-FTE

 

[uHu]

Looking at the car, rather than pix, shows me that the movement of that cable between the engine and the relay, happens between one cable clip on the air filter housing (static) and one clip just above the turbo (engine movement). So, the rear side of the filter housing and the bracket for the VSV for turbo, are the two crucial points.

 

[SteveS]

Thanks for the extra info uHu - once I get my truck out of Southampton container yard I'll be doing this little install

 

[WomblingFree]

Is there a specific reason why you want to reconnect it?

Info from Toyota suggests the heater is only there to satisfy pollution requirements, most of which occur at switch on. The heater is only turned on for a few seconds so its certainly not pre-heating the air charge for Siberian starts.

At power on, the intake heater matrix pulls a lot of current (think it has a 150amp fuse ?) which might mean the difference between being stranded and having the engine start. Here in Oz, we rip it out along with the heater matrix as its very restrictive on airflow.
Have you checked that you still have the matrix in the housing?

Lots of info in this thread although you might have to sign up to view but thats free - http://www.lcool.org/forum/viewtopic.php?t=2191

 

[Towpack]

The heater is only turned on for a few seconds so its certainly not pre-heating the air charge for Siberian starts.

That's exactly what it does do and was designed to do. If I lived in a hot climate and was maybe thinking about performance increases then I'd probably remove mine also. JMO