dbm7

Best guess would be light (combination) switch....but here's the wiring diagrams... https://mega.nz/file/6VR1nQpS#OluHuuezNX-K9A9HxbpjmTaSxQ1dsTuOjY1FQcI1Ymw https://mega.nz/file/ScJ2mQSR#70fgte2VGiQxFCPzaOu6JhtY1Y2zie_Xu7AsAFmPQis

All the schemas I can see, indicate your typical setup of ATF 'cooler' (read: heat exchanger) in the bottom radiator tank..ie; https://nissan.epc-data.com/stagea/wgnc34/5413-rb25det/engine/214/ ...but I can prattle on a bit here. These trannies have a thermistor in the sump ~ the TCU reads this and 1. bumps the line pressure up when the ATF is 'cold' and 2. prevents the TC lockup clutch from operating, until the ATF comes up to minimum operating temp (keeps the ATF 'churning' through the TC so it heats up quicker) -- trigger point is around 55C. In these conditions, the engine coolant temperature rises faster than the ATF temperature, and also helps heat the ATF up, which is why it's best to think of the in radiator tank setup as a heat exchanger ; the heat can flow in both directions... ...with these trannies, the 'hot' ATF comes out the front banjo bolt, flows through the cooler/heat exchanger, and returns to the box via the rear banjo bolt. This gets a mention, due to the wildly different opinions wrt running auto trans fluid coolers ~ do you bypass the in radiator tank altogether, or put the cooler inline with the in radiator tank system...and then, do you put the additional cooler before of after the in radiator tank system?... ....fact is the nominal engine operating temp (roughly 75C), happens to be the ideal temperature for the ATF used in these trannies as well (no surprises there), so for the in radiator tank system to actually 'cool' the ATF, the ATF temp has to be hotter than that...lets say 100C -- you've got 25C of 'excess' heat, (slowly) pumping into the 75C coolant. This part of the equation changes drastically, when you've got 100C ATF flowing through an air cooled radiator ; you can move a lot more excess heat, faster ~ it is possible to cool the ATF 'too much' as it were...(climate matters a lot)... ...in an 'ideal' setup, what you're really trying to control here, is flash heating of the ATF, primarily produced by the TC interface. In a perfect world, wrt auto trans oil cooling, you want a dedicated trans cooler with builtin thermostatic valving - they exist. These should be run inline and before the in radiator tank system ~ when 'cold' the valving bypasses the fin stack, allowing the ATF to flow direct to the in radiator tank heat exchanger, so it works 'as intended' with helping heat the ATF up. When 'hot' (iirc it was 50C threshold), the valving shuts forcing the ATF through the cooler fin stack, and onto the in radiator tank heat exchanger...and you sort of think of it as a 'thermal conditioner' of sorts...ie; if you did cool your ATF down to 65C, the coolant will add a little heat, otherwise it works as intended... ...the 'hot' ATF coming from the front bango bolt, is instantiated from the TC when in use, so all/any flash heated oil, flows to the fluid-to-air cooler first, and because of the greater heat differential, you can get rid of this heat fast. Just how big (BTU/h) this cooler needs to be to effectively dissipate this TC flash heat, is the charm...too many variables to discuss here, but I just wanted to point out the nitty-gritty of automatic trans fluid coolers ~ they're a different beastie to what most ppl think of when considering an 'oil cooler'... /3.5cents

Yeah, this is one of the most annoying things about nissan part numbers... I've got an unrelated example... Image is of the AT output shaft ~ they have the same part#, but clearly the shaft on the left is beefier design to that on the right ...the difference (essentially) is the 'lighter' shaft on the right, is for engines up to RB25DE (this includes RB20 variants) : the shaft on the left is for RB25/26DET(T)....are they interchangeable? Yes...but obviously one shaft is going to be stronger than the other...and, the lighter shaft is around USD115, but the heavier shaft closer to USD150...same part#... ...epc-data usually tells a tale ~ the amayama listing for 39100-23U60 has a note "Longest side is between 60 and 105 cm" ; no such info is there for 39100-23U70 ...and given the great disparity in price between the 2 parts, it makes me at least curious (to the point of caution) where the 'extra money' went? ...ie; these 2 parts have a cost difference that (to myself at least) isn't explained by 'plastic boot'...ie; with amayama there's AUD700 price difference ...plastic versus rubber?...I'm not seeing it like that...and 60cm ~ 105cm...??...that's a huge disparity....something hinky going on here... I'd try searching by VIN, not model... /2cents

I'd probably start with checking the output of the accessory relays (you can check control side while you're there)

Yeah, all good ...got your postal addy as well ; I'll box the stuff in the next couple of weeks, you can paypal me later..

Did some FASTing ...got the impression that the actual part# was a moot point ; seems all of these hardlines for coolant are discontinued/NLA... like, I take it you're after the hardline that bolts onto to the manifold...that's NLA according to amayama & nengun .... ...just to clear up some confusion, they typically mounted the AAC valve to the intake manifold somewhere near a coolant passage, so the body of the valve heats up & holds it open when engine's up to temp - no coolant flows through the valve, it's a mechanical, thermal connection.

Wrt the engine, you're very much limited by 'production quality' as to how much extra power you can extract from them (I'm talking i6 red-motor) -- a lot here depends on how 'authentic' or 'period correct' you want the modifications to be... ...I'm too old... <grin>...the first true performance engine Holden made, was in the HD/HR models ~ this was the 'X2' performance pack...it came with twin downdraft strombergs on an otherwise unimproved intake manifold, with a two piece exhaust manifold (reckoned to be as good as extractors)... ....these engines were built upon the '179HP' cylinder block, which included extra webbing in the casting to make it stronger and less susceptible to block distortion... The next performance i6 came out with the HK Monaro (also found it's way into the LJ GTR Torana ... the car I wish I hadn't sold)...it had pretty much the same manifold setup, but was built against the '186S' block...this block retained all the extra webbing of the 179HP block, but added a forged steel crankshaft (instead of the stock cast crankshaft), because it was possible to snap the crank... ...apart from the inherent weaknesses in the stock (cast crank) blocks, the next limiting factor is the cylinder head porting & combustion chamber design, and the actual valve sizes. Back in the day, you could buy a 'yella terra' cylinder head (from stage 1 to stage 5 gradients), and this was the way to get serious power out of them -- with the extra breathing of these heads, you could fit a triple SU or DCOE Weber setup... ...obviously, these mods were a waste of time on a stock cylinder head/camshaft grind. My housemate rebuilt the i6 in his VH dunnydore about 6 months back -- this is a 186S block with the 12port 2850 blue motor head and intake/exhaust manifolds, with a dual throat Weber off an XF Falcon mounted on an adapter plate ; it's not a bad makeup...got more torque & fuel economy just light-footing it about on the first throat, but stand on it and it makes more giddy-up than the standard 2850 blue motor that it replaced. Personal note: I'd just fit an RB30 and be done it it 😃

I PM'd you my email address 😃

Do you still need the wiper motor and stuff?

Oops... I meant to include the connector view... BR/W - power from fuse L/W - motor negative to fan control amp (and off to HVAC pin19) OR/B - PWM signal (from HVAC pin20) B -- ground

G'day ... first up, I very much doubt that's a resistor network (as used also for this job), but the part# looks right. The description of 'power module assembly' looks to be nissanese for 'PWM driven, ground switched, DC motor speed controller'.... the circuit in the schematic kinda infers that's the case... ...with the transistor symbol appearing in the unit described here as 'Fan Control Amp(lifier)'....being driven by pin20 on the HVAC unit, and a feedback signal on pin19 from the motor negative terminal for some reason (might be motor fault detection, maybe they detect commutator switching to determine motor revs as well, I dunno)... but if they are counting commutator spikes, a bad segment (or really worn brushes) will throw a spanner in the works... The motor itself will as said be brushed DC with segmented commutator, rated at 12VDC nominally ~ now-a-days I just unplug them, determine the positive wire, and hook them up to a variable power supply and find out how much current they draw, if they work etc etc ...you can also check for bad segments...ie; set the power supply up to feed 1volt @ 2amp max, then watch the wattage count as you slowly rotate the fan blower motor through a complete revolution ; any bad/dead segments will be clearly evident...some folks would just say determine the positive wire, and feed it battery voltage, and if fan spin, you've got a win...<grin>... well, at least that infers it should do something when plugged back in, and the HVAC unit commands it to run... and if it doesn't, you suspect the module, but you should check the PWM signal on pin20 is actually present, and if it is, blame the module ...

Ahh...should have been clearer ~ there's 2 ... SMJ = super multi junction (connector)... ...this is connector 6 & 25 in above image -- body harness to engine loom (6) & body harness to main loom (25) Headlights go to front via connector 6 ; fuel gauge goes to tank sender via connector 25 ...like I say this is R33 diagrams, but at a pinch R34 won't be too far different. *IF* the two ground faults are related, this can be the only place where both wires converge (as one runs to the back, the other to the front)... ....thing is, you probably need to establish if the faults are related (unless you examine that area and find obvious chaffing on the looms there to body ground)....*IF* the fuel gauge is still broken (full needle deflection), I'd be headed for the boot, remove fuel sender wire, key on and measure the voltage there ~ it should be roughly 10volts. If that's ok, check sender to ground resistance...if this is a dead short to ground (and there's fuel in it), then sender has failed or something funky has happened to wiring in the tank. edit: ahh...rereading the thread, this is R32....above fuel sender test still valid tho'

Correct ~ fuel gauge receives power (usually about 10volts) from a linear regulator on the cluster board (gives a stable reference voltage), and as you say, via a variable resistor to ground (float level) ; high resistance when tank empty, a low resistance when tank full. As you surmise, if the fuel sender wire was shorted to ground, there'll be full defection of the fuel gauge needle. I haven't got an R34 wiring diagram, but going by the R33 spaghetti schematic, about the only thing common here between headlight & fuel gauge circuits is the SMJ connector...

Yeah, R34 with RB25DE likely has a 4AX01 box in it, which is a medium duty auto ~ with the RB25DET mill, it would've been fitted with 4AX00 (4AX13) heavy duty build (same case, different internals). An RB25DET will lunch on a medium duty 4R01 auto in pretty short order ...to give you some visual idea of differences between the 'medium' and 'heavy duty' boxes, you only have to look at the 2/4 band for comparison...it's chalk and cheese...(plus bigger high clutch, extra pinion in the planetary sets, higher oil pump output, different bearings, higher TC stall speed )... You can control them with just about any aftermarket TCU for electric-over 4-speed with TC lockup clutch (ie; the GM 4L60E and others)...I have a custom standalone TCU that includes MAP sensor (for turbo applications) along with TPS, RPM, and line pressure monitoring...in other words, I don't use any ECU signals...no real need to.

Very unlikely...

He's right ~ there is no 'magic' with stuff like this ... it is more likely that in the process of looking for the short, the loom/wire 'incidentally' got moved in the process, thus removing the short ~ now, that maybe a wire (in a loom) rubbing against the edge of some grounded metal, that's worn through the insulation, causing the (now intermittent) short to ground. If one wire in a loom has been damaged in this fashion, it's reasonable to presume that other wires beside it may have also be damaged, and now exposed...you can bet the green crusty copper corrosion will start... ...that'd be a pisser, Murphy's Law steps right in as GTS observes...but worse, something like that is easier to find when shorted...ie; unplug bulb and fuse, and put multimeter in continuity mode so you get constant beep, and carefully poke about hoping to find if some movemet of the harness stop the beeping.... ...it's still all a bit Arnie tho' ..It'll be back... 😃

...yep, in the dark of a wet rainy night most likely 😃

Yeah. air pressure leakdown test is where I would be headed next here, using one's ears to determine whether it's the valves or bores/rings leaking...

Duh... to answer my own silly question, it's actually described in the FSM... ...400 pages away at the end of the manual, for RB25DE/DET signal descriptions, it cites the TPSwitch signal action, is dependent on the TPSensor value ~ this tends to infer the builtin POT voltage signal is the primary, and the switches are fallback/secondary should the POT fail/TPSensor signal lost (and switch alone with no TPSensor signal allows for base idle speed setting).... makes sense... they (TPS units) used to fail/wear the POT with time, they're not exactly built to last ~ having the switch as a redundancy gets around this...(or, it's less likely both signals would be lost as they're on different power rails)... and of course wrt RB26DETT, you have to electrically disconnect the IACV solenoid from the harness, to defeat idle air control...

Same thought crossed my mind ~ depends on how one connotes 'stalling'...ie; gets a rough/stumbling idle as it get warm until it stalls... or... idles ok and simply falls-over when it gets to temp... ...you can test the whole circuit with a couple of resistors ...unplug coolant temp sensor, bridge terminals with a 2K7 resistor (ECU will do cold start), or with engine warm bridge with a 330R resistor (ECU will consider engine to be at normal operating temp)...it's a quick way to check wiring integrity/ECU response when you don't have a multimeter handy ...

For sure the later RB26 variants had a different setup (6 cam voltage sender?), but the RB25DE/DET share the same ECU pinout/PCB footprint, and at the ECU plug it ends up being 'throttle sensor in' & 'throttle sensor out' (to A/T TCU) ...you stick a multimeter on these pins and you'll find them directly connected (0 ohms) ; I had an pair of Nissan ECUs on the bench long ago, and I noticed this throttle sensor in/out link, actually linked to an op-amp ...which was unpopulated on the NA board, but present on the T board and I went 'ah-ha!' in some moment of clarity... ...it wouldn't surprise me if they changed strategy here though (in the software and actual monitoring of this signal), because they did with other stuff (A/T signals).. and 0.45v as a trigger point makes sense, as that's what the external TCU units expect at idle ; kudos, thanks for that insight...I suppose it boils down to whether or not Consult can display real time data of that signal's voltage... ...in any event, it presents the same target...ie; rotate TPS unit to achieve 0.45v to suit both ECU&TCU, and where do you goto from there? Just disconnect TPSwitch connector and/or that plus TPSensor connector....or do you go for the throat and disconnect IACV solenoid and see if it still stalls? (probably throws a recoverable fault code and goes for default idle strategy?)...

It's actually one of the worst bits of Nissan nomenclature (also compounded by wiring diagrams when the TCU is incorporated in ECU, or, ECU has a passthru to a standalone TCU).... the gripe ~ they call it the TPS, but with an A/T it's actually a combined unit ...TPS (throttle position switch) + TPS (throttle position sensor).... ..by the looks of it (and considering car is A/T) you have this unit... https://www.amayama.com/en/part/nissan/2262002u11 The connector on the flying lead coming out of the unit, is the TPS (throttle position sensor) ...only the TCU reads this. The connector on the unit body, is the TPS (throttle position switch) ...ECU reads this. It has 3 possible values -- throttle closed (idle control contact), open (both contacts open, ECU controls engine...'run' mode), and WOT (full throttle contact closed, ECU changes mapping). When the throttle is closed (idle control contact), this activates what the patent describes as the 'anti stall system' ~ this has the ECU keep the engine at idling speed, regardless of additional load/variances (alternator load mostly, along with engine temp), and drives the IACV solenoid with PWM signal to adjust the idle air admittance to do this. This is actually a specific ECCS software mode, that only gets utilized when the idle control contact is closed. When you rotate the TPS unit as shown, you're opening the idle control contact, which puts ECCS into 'run' mode (no idle control), which obviously is a non-sequitur without the engine started/running ; if the buzzing is coming from the IACV solenoid, then likely ECCS is freaking out, and trying to raise engine rpm 'any way it can'...so it's likely pulling the valve wide open....this is prolly what's going on there. The signal from the connector on the flying lead coming out of the unit (for the TCU), should be around 0.4volts with the throttle closed (idle position) ~ although this does effect low throttle shift points if set wrong, the primary purpose here is to tell TCU engine is at idle (no throttle demand), and in response lower the A/T line pressure ... this is often described as how much 'creep' you get with shifter in D at idle. The way the TPS unit is setup (physically), ensures the idle control contact closes with a high margin on the TPSensor signal wire, so you can rotate the unit on the adjustment slots, to achieve 0.4v whilst knowing the idle control contact is definitely closed. The IACV solenoid is powered by battery voltage via a fuse, and ground switched (PWM) by the ECU. When I check them, I typically remove the harness plug, feed the solenoid battery voltage and switch it to ground via a 5watt bulb test probe ; thing should click wide open, and idle rpm should increase... ...that said though, if it starts & idles with the TPS unit disconnected, and it still stalls when it gets up to operating temperature, it won't be the IACV because it's unused, which would infer something else is winking out...

Hahaha, yeah.... not what you'd call a tamper-proof design.... but yes, with the truck setup, the lines are always connected, but typically they sit just inside the plane of the rear metal mudguards, so if you clear the guards you clear the lines as well. Not rogue 4WD tracks with tree branches and bushes everywhere, ready to hook-up an air hose. You can do it externally like a mod, but dedicated setups air-pressurize the undriven hubs, and on driven axles you can do the same thing, or pressurize the axles (lots of designs out there for this idea)... https://www.trtaustralia.com.au/traction-air-cti-system/ for example.... ..the trouble I've got here... wrt the bimmer ad... is the last bit...they don't want to show it spinning, do they.... give all the illusion that things are moving...but no...and what the hell tyre profile is that?...25??? ...far kernel, rims would be dead inside 10klms on most roads around here.... 😃

There's actually quite a bit of aftermarket for automatic/manual tyre deflater/inflater systems ... many will have seen YT vids of trucks on tropical forest roads (read: mud), with air lines leading from the chassis/bed down to a hub piece, which in turn connects to the tyre valves ...most of the time only used on the drive axles, to adjust tyre pressures and get some grip....(bit like letting air out of a 4WD to get traction on loose dirt/sand)...

No worries, now that I'm closer to 70yo than not, this sort of stuff will one day be 'lost knowledge'... and even now, I wonder just how many folks out there have the Kent-Moore J34291 shim setting tool set to set end clearances rebuilding these...but right the now, there's less and less hard parts available, and you'll be headed to the wreckers to buy a donor box if it's worn out...(or pay a shop to do exactly the same thing). In a way, it's fortunate the 4-speed was so popular, because there's still heaps of consumables (banners kits, bearings & plates etc) around ~ these early 5-speeds weren't exactly that prevalent, so there's not quite as much about for them... but it's a race between perceived demand for these parts, versus how much they fetch at the shredder for recycling purposes...