I use that switch all the time to get the heater going and get the engine into a good temp range before driving it hard. I also use it to get the battery charged faster, at idle when the batteries are down it often charges at about 13V once I flick the swith and the revs jump it is then charging at 14V.

 

i have recently talked about my patrol a little rough starting in sub zero temps and even at slightly freezing temps,this is normal i have learned and can't really be avoided as the engine gets really cold and is a little like getting you out of bed on a very cold day,a little grumpy,my apologies in advance if a thread has already been posted to cover this topic, but i can't find one.
anyway this heat switch? what on earth is is for,i understand it just keeps throttle open for a long period,but what's so differnt to just stabbing the throttle with your foot when you start it up?? i don't see the point of this and seem to think it's of no advantage at all,if a little silly even.

maybe it is there to serve another purpose i have yet to notice?

It lets the engine warm in a controlled manner, as in 'minimal load conditions'. The engine parts and oil get a chance to come up to operating temperature before the engine is loaded by the transmission and higher reving, therefore when you get going engine wear is reduced a bit.

Can't say i use it in Qldl as the engine oil will be siting at ambient temperatures of between 18 & 30 degrees for much of the year and i don't go to hard until the auto box has warmed up anyway, but in colder climates it should help.

Like some have said. I also do use it a fair bit to make sure there are extra volts going into the batteries if i’m using an electrical accessory like an air compressor.

In the past I drove a good few old school diesel Peugeots and Citroens in cold climates, they actively advised in there manuals not to idle the engine to warm up. No idle up switch on those. Not sure why but I suspect a diesel should have a little rev to prevent sooting up during prolonged idling.

I once considered getting one of those coolant heaters from the US for a bit of luxury when I’d get into a freezing car in the morning. The burner, set on a timer, uses diesel to heat and circulate coolant to provide instant heat when you jump in with the engine already up to temp. Couldn’t afford it at the time and subsequently moved to sunny QLD.

Grogey

 

Cold climate Patrol versions also have an exhaust gas control valve near the main muffler, when you flick the heat switch the valve closes to promote heating of the engine. Dan's Patrol may have one, my GU doesn't have it. I use the heat switch a lot to save friends with dead batteries!

 

some good points lads but i have often let the patrol idle an odd morning with no heat button on and it bought the temps up nearly as fast as without the heat button,my point is i'm usually in a hurry in mornings and end up sitting in the patrol when i just am about to leave,i rarely end up going out in bad mornings first to let it idle cause i'm just lazy about it
so when i am in it i do use the heat button to warm it first for a few minutes but see no real point cause i can rev it slightly with my foot after a few minute or so.

anyway,if you found uses for it and you think it works for something well i guess that's good!!

i think nissan would have been better off with another glow plug heaters switch to warm them up better in the mornings rather than the factory ignition ones which don't seem to be that great in cold temps.

 

Where is this heat switch?

 

near the drivers door below the electric mirror switch on the dash of course under heater vent

 

That was my guess anyway,thanks.
When i bought my patrol i asked the dealer what that switch was.
They didnt know.

 

I use the switch to increase revs for A/C, when idling. Good if I jump out at shops with family still in the car, opening gates in station country etc.
Coaches often have the same thing, that is a switch to up idle for A/C.

 

And it's great to bump your knee on and then panic about why the engine just doubled revs and your knee hurts at the same time.

 

Ok I know this is an old thread but better than staring a new 1.

When I flick the heat switch on my revs are lucky to go up by 100rpm, yes 100rpm, not 1000. My Gu normally idles at about 600 - 700rpm, when I flick the switch it goes to 700 - 800rmp.

Is there a way to change this? I have checked a few things but can not find a way to change it

My father in laws idles at approx 1200rpm when he flicks his heat switch on.
I thought since our trucks only have a couple of months differance between build dates (his july 2000, mine sept 2000) they would be the same.

 

Mines Oct 2000 and it gets to 1200rpm with the switch on, don't use it much but it does come in handy from time to time for things mentioned like a few extra volts when needed, so I think you may have an issue with yours.

 

Yeah, the switch puts it onto about 1000rpm, but still, you should be getting closer to 1000rpm than just 800.

Batches of switches and controls can vary pretty greatly actually.

What do you need if for?

 

Yeah, the switch puts it onto about 1000rpm, but still, you should be getting closer to 1000rpm than just 800.

Batches of switches and controls can vary pretty greatly actually.

What do you need if for?

where i am living at the moment can get abit cold over night. Not uncommon to go below freezing over night. Would like to be able to use it to warm the engine up in the morning before I leave for work, especially on the cold mornings where I start at 5:30am.

Well more for next winter as we are comming into summer

 

I remember a thread on this couple of years back where a few thought it would be good to be able to use it as a crawl switch as well, though as soon as in gear cuts out, has anyone looked at this further.

 

I like the swtich the on diesel version. It should be standard on all as its handy when using a ARB Comp to keep the current up.

 

I have the manual transmission, it must sense off the linkage somehow because as soon as you move from neutral the revs drop.

If someone can work out where to unplug the sensor we can try it as a rev crawler for low range.

Regards
Spinifex

 

On the RD2.8TD it worked off the temp control as well. As soon as it hit working temp, it idled back down. So no good for anything else.

 

On the 3,0 works pretty much most of time, not on temp.

 

Very handy item...... select after service (oil change) - RPM up means oil px is up, check for oil leaks. Also, same time, run a volt meter across Batt terminals as a basic electrical check.

My 2 bobs worth

 

Hopped into the Datsun this morning and it idled at 1200 rpm... pulled off intercooler checking for vacumn leaks . blown gaskets... ask local mechanic why it was suddenly idling so high.. had everyone scratching their heads then when driving home the missus noticed a HEAT SWITCH light burning... flicked it off and idle went back to 600 rpm............ we never even knew it had a heat switch..... BLOODY DATSUNS!!!