Slartibartfast

Yeah, the dimples on the cover are approximate at best. Go by the tooth count between the marks on the sprockets. 40 teeth between the cams, 43 from driver's cam to crank. If it's loose between the cams, that's slack you don't have where you need it get it around the tensioner, so that could very well be what's holding you up.

That's a whole lot of weird. I don't know the R50's engine control all that well, and the diagram in the manual isn't as helpful as I had hoped--it shows lots of fuses, but doesn't label them, so I don't know exactly where those two are supposed to send power. EL shows a bunch of fuses, but I don't see any labelled ECCS1 or 2--though considering Nissan calls the fuel injection system ECCS, yeah, makes sense they're for the computer. The question is whether they're powering the computer itself, or something the computer controls. I'd be surprised if the computer was messed up enough to blow fuses, but still sorta working. Is anything else not working? Any obvious damage to the wiring harness? Anything plugged into the OBD2 port? Any prior flood/water damage? Any trouble codes? I'd try and run down anything else it could be, including checking ground points, before dropping $600 on a computer. Also IIRC the computer has to be programmed to accept the body control module, or the anti-theft system gets pissed off. I think there's a relearn procedure for the throttle body, too. If you haven't yet, download the '04 service manual from Nicoclub. It's late enough that an annoying amount of it is just hand-holding for using a dealer diagnostic system that you don't have, but they do slip up and include actual useful information here and there.

Not a lot of R51 owners on here, unfortunately. I don't know the platform or the engine well enough to speculate apart from the usual stupid stuff--check the tires, check for codes, maybe have a look in live data to see if various sensors are reading where they should.

It was a while ago that I did mine, but I vaguely remember the tensioner being able to sit in two orientations, one rotated up and one rotated down, if that makes sense. You want the Allen key hole below the nut. I'm not sure this is even possible to screw up, but it's all I can think of, unless the tensioner is wrong (compare to the old one) or there's a bunch of belt slack between the cams because you didn't turn the one that jumped quite back to where it was. Speaking of, one of my cams jumped too. I turned it back the way it came, no harm done. It should be fine unless you try to force the cam to turn the rest of the way around. I do remember having to fight a little to get everything lined back up afterwards, though. While you're in there... when I did mine, I didn't replace the crankshaft seal, because it wasn't leaking. It began leaking as soon as I got it back together, and I had to tear it all apart again. Don't skip the crank seal.

Aha! Good work tracking it down. Figures it's the alarm, those things are a menace. Joining the two black/yellow wires will bypass the alarm. I did that on mine, for a while, but later developed an intermittent weak start/no start issue (acted like the battery was dead, then cranked right up the next time I turned the key) that didn't clear up until I removed the alarm harness in its entirety. I'm not sure what was wrong at that point, given the alarm brain was already in the bin, but I haven't had a problem since the harness joined it there. These systems were installed after the fact, so they're pretty easy to make go away. Two or three wires are scotchlock'd into the harness, but most of them plug in between the truck's actual harness. So you unplug the ignition switch from the alarm harness, unplug the alarm harness from the truck harness, plug the ignition switch into the truck harness, and it's like the alarm was never there. Same deal for the door locks, at the A pillar IIRC. Two or three wires go through the firewall to the siren and hood switch, but they're bundled with the wiring for the fog lights, so don't just cut the lot. The alarm harness has each wire silkscreened with its purpose, which the main harness doesn't, so if it doubt, look for the silkscreen. There's a TSB with the alarm system wiring, I'll see if I can dig that up again. I'll bet if you plug the door lock timer back in, the power locks will work properly again, now that the alarm isn't feeding it garbage.

If it's got spark, but won't kick on ether, that suggests the timing is way out. Either the last person to replace the dizzy didn't time it right, or the timing belt slipped. The dizzy's easy enough to set up if you have a timing light. The belt can result in bent valves. I'd check the belt first.

Some states use salt, some don't. The stuff eats cars for breakfast. I need to get rid of my parts car soon-ish anyway, might have to drill out some spot welds and see how much trash it's collected between the layers.

I'm not entirely sure what the door relay is--do you remember the full name/location on this one? I get that the door lock timer is disconnected, I just don't remember a door relay off the top of my head. As level9 said, it sounds like the switched ground for the dome light is grounded somewhere it isn't supposed to be. Worst case, it's a random rub-through somewhere in the harness, but before we assume the worst, let's see if we can get a better idea for where--if it's in the harness at all. Is the rear dome light also stuck on (with its switch in the auto position)? The front and rear dome light have a diode between them, so if the rear hatch is open, both come on, but if only the side doors are open, only the front dome comes on. Sounds like you've already taken the rear hatch switch out of the equation, and I'm assuming you taped up the spade terminal to where it's not grounding out on a bracket or something. If the switch is not the problem, and the rear dome is still on, that suggests a fault in the cargo area side of the circuit--and there ain't much else to it. Either the dome light itself is somehow shorting switched ground to constant ground, the switch wire is busted where it flexes between the hatch and the body, or the wire is cut/rubbed through/chewed through and grounding elsewhere along its run. If the rear dome light works properly (and comes on when it's set to auto and the switch wire is grounded), then you can rule out the circuit from the diode back. Does yours have the front footwell lights, and are those staying on, too? Those are on the same circuit as the front dome light, but they are not controlled by its switch. If turning off the front dome light turns those off too, that suggests the front dome light is somehow bridging switched to constant ground. Unplug the dome light and see if the footwell lights go out. If it's not the cargo area circuit, and the footwell lights work as expected (or you don't have footwell lights), I would set the front dome to auto, and then unplug the few things that are on that circuit one at a time until the light goes out. I know you've replaced the door switches already, but I would still start there. IIRC they ground to the body, so you don't have to unplug them, just take the screws out and let them hang. Check what you can see of their wiring while you're at it, make sure it's not cracked or chewed. Those door dingers are probably a long shot, given they're working, but they're not too hard to get to, so unplug those too and see if that gets it. The stock keyless entry/alarm system also ties into the dome light circuit, so if that's still in there, try unplugging that too (it's the square box under the driver's seat--not the roundy one, that's the ABS). If that doesn't do it, I'd try unplugging the cluster as well. I should note that I have not heard of any of the above components causing this problem, or dying due to a battery arc (did the guy seriously try to remove the alt with the battery still hooked up?). They're just all I can think of that's on the dome light circuit. If all of that stuff is unplugged, and the light is still on, then, yeah, you've got some wiring to chase. Let me know if you end up there and I'll have a poke at the EL section, see if I missed something, or if there's an easy disconnect somewhere else in the circuit so you can narrow down the search area a bit more.

Wouldn't hurt to check/clean the MAF. The plug on the MAF tends to loosen up and cause issues, but when that was acting up on mine, it did the opposite--ran fine when my foot was in it, but forgot how to idle.

AFAIK the R50 is the only vehicle with the 33-spline H233B and rear coil springs sold in the US, so your only whole-axle donor is going to be another R50. I don't know that swapping the whole axle would be any less work than swapping the early Xterra 3rd member into your existing axle (assuming you can find one). If you do go looking for a whole R50 axle, avoid '03/'04--they got nerfed down to less breakaway torque than the lug nuts take. Make sure any rear axle or 3rd member you pick up has the same gear ratio as your front diff. There's a plate in the engine bay with the VIN and other info. You want the number that starts with HG. Should be HG43 or HG46. I'm happy with the LSD in mine. It's not a locker, and it never will be, but it's a big upgrade over an open diff. And mine was made before Nissan started nerfing their LSDs, so I didn't have to open it up and fix it! It does get a little tail-happy in the snow, though, which is probably why the later LSDs were nerfed.

I had no idea that section of the floor was double-walled! Makes sense, though--rust loves metal sandwiches, especially once dirt and moisture get in there. I went and had a look at mine, and it doesn't have the hole in the middle, but it does have a couple of holes above each spring perch. My floor is solid so far (under the seats, at least), but I may copy what you've done with the wax to keep it that way. I'm tempted to try and find rubber bungs to fill those holes when I'm done. If the top is closed up, and the bottom is open enough to leak wax, surely that's enough ventilation, right? No sense leaving them open for stuff to get in that might not be able to get out. I'm convinced that's what killed the frame on my '95--it's easier for dirt to get into the frame than it is for it to get out, so it just sits in there, clogs up the drains, and forms a wet (and salty, given where that truck was from) sponge up against the steel. Edit: I looked up the wax spray you're using, and the Amazon link says it's "restorative scalp and hair care."

I would be surprised if there isn't some rubber strip material out there that could be cut to size and stuck on.

I don't think that strip is factory. Probably an aftermarket add-on to prevent door dings.

Short answer is yes. Here's a tutorial for resoldering the lock timer, not that there's much to it. With that said, I tried resoldering the timer in my '95, and it didn't change a whole lot. Maybe I did a half-ass job, or maybe something else was wrong. The locks in that thing were downright malevolent, especially when it was cold outside. Unlock the doors and they'd lock again immediately, or unlock only part of the way (in retrospect, I suspect the linkages were gummed up, which may have been at least part of the problem) and then lock again as soon as someone pulled on the outside handle. Sometimes the lock motor pushed back when I tried to turn the key in the door lock. Naturally it only acted up when it was cold enough that I couldn't be arsed to figure it out, so I just lived with it, and learned not to close a car door unless the window is down or the keys are in my hand. My '93 isn't nearly as posessed, but it does occasionally re-lock itself when it's cold. I cleaned and lubed the front lock cylinders and spray-silicone'd the crap out of the linkages this spring, which made them move much more easily. If that doesn't clear it up, I may give the lock timer another look.

Had a look. NPD shows part numbers for crossbars between the factory side rails. Two different crossbars are listed, as well as a crossbar kit. (I didn't check whether they're different with/without the sunroof, can't imagine why they would be.) Naturally the singles are discontinued, and the set is out of stock. You might get lucky at a wrecker, though.

If all you want to do is disable the power locks, you could just unplug the door lock timer. Weird that shorting the power lead to the alt would cause all that. Sounds like the timer got messed up real good.

Someone posted pictures of a unistrut (?) rack they'd made for an R50 a while back. Looked hell for stout.

The question is whether your Polish Pathy has the same specs/wiring as the US models. Hopefully it does! Otherwise this may be entertaining to track down, unless you can find a service manual for your local variant. I would start by downloading the 2000 US-spec service manual from Nicoclub. It should have schematics in the EL section for the radio options. It shows a base system and a Bose system. See if you can match up the wire colors and plugs to what you have to confirm which system you're working with. If it doesn't match, try the '97 manual--it shows a base system without an amp, a base system with an amp, and a Bose system with an amp, so you've got one more variant to check against. Also, given you have a '97 head unit, you can check it against the '00 to see if it's got the same connections. It sounds like you may have a factory amplifier wired to the speaker output of an aftermarket head unit, so you're hearing a signal that's been amplified twice--once by the head unit, and then again by an amp that wasn't expecting an already-amplified signal. There are two ways of dealing with this. One is to connect the wires going to the amp to the line-out RCAs on the back of the head unit (or a line-level converter if the headunit doesn't have those), so the amp gets the signal it expects. (I would expect a plug-in harness to do this already, if it's built right--if that's how the aftermarket HU was hooked up, then you might have a bad amp.) The other option is to bypass the amp, either by running new wires to the speakers or by cutting the wires to the amp plug and joining the inputs to the outputs. I didn't know better when I put a head unit in my '95, so I wired it as described above. The sound quality wasn't as bad as you describe, but the beeps the head unit made were deafening. I did notice a little better bass and clarity when I found out about the amps and bypassed them. It's also entirely possible that your 24-year old speakers are in a bad way. You might try looking in through the grilles with a flashlight or something to see if the foam around the cones is still there.

The EF&EC section of the service manual (free download from Nicoclub) is your friend for this stuff. Should have troubleshooting for each code, including circuit diagrams and sensor tests.

That makes sense. Good to know the Lares is an option if you don't mind taking it apart.

I wouldn't be surprised/concerned about a little misalignment, but the Lares was enough off from mine that I was concerned I'd damage something trying to make it work. It's a little exaggerated in the picture due to the parts not being lined up straight, but even straight on it was off by enough that I didn't like it. I measured 65mm center to center on the Lares, but that was from the bolts, and I don't remember checking whether they had wiggle room or not. The Z car parts looked different to me, but I only looked at pictures online.

I used a similar socket to the top one you linked. It's a bit fiddly to keep engaged (only grabs in two places), and IIRC I had to do a little grinding to make the pegs fit right. But unless it's made of Jolly Ranchers, you're overtorquing the bejeezus out of the bearing, or you try to take it apart without taking the screws out first, I think you'd have to try pretty hard to break it. The plate you're seeing might be the lock nut, which is the component that the socket turns, or the lock washer, which goes over the nut and has holes for the screws that lock it in place. I don't think the second tool you linked would fit anything on an R50.

Well, it sure wasn't the right part for the truck! The packing sheet (and the box IIRC) said it was the 210, but I don't remember the part itself being labelled. Guess it might've been the wrong part in the right box. Did you measure the bolt spacing on your splined yoke piece? Mine's 60mm between centers. I'm wondering if Nissan made different widths for some reason. This reminds me that I need to get around to installing mine.

Nissan was still running the VG33 in 2000, so if you're looking for an engine, that's not a match. The R50 LSDs were nerfed hard from what they were in the WD21. Hawairish has an excellent writeup for repacking the R50 LSD to be worth a damn. The early (first couple years IIRC) Xterra LSD is supposed to be a drop-in upgrade if you don't want to tear the diff all apart, but you do need to check the gear ratio and make sure it matches the front end. @Camperdan, thanks for the correction! Shows what I know about the VQ35.

That's a good question. A used engine/trans would be easier (and probably cheaper as well!), but might have its own issues--like I mentioned, some of the early VQs had oil consumption issues. (I've heard various theories about what actually goes wrong--PCV design, cylinder taper, catalytic converter bits getting sucked back--but I don't remember reading about someone with the oil consumption actually fixing it. My dad's '03 burned a quart/1k miles before 100k, and it acted like the valve stem seals were bad, but we never tore it down to see what was wrong with it.) Rebuilding yours (or a donor engine) may get you a better product, assuming you don't mind the added cost and time, and of course assuming you have the skills to pull it off. Also consider compatibility. Nissan changed a few things across the four years the VQ was used in the R50. '01 and '02 were both cable-throttle ('03-'04 were drive-by-wire), but IIRC the '01 had different valve covers and coil packs? I would expect '03/'04 engine to work if you used your old intake, but I don't know that. Do some research on this to make sure you get the right stuff. It'd be great if a more modern VQ (with the early bugs ironed out?) would work, but that sounds like a science project waiting to happen--who knows what else they've changed in the last twenty years. Unless you've got the five-speed (rare with the VQ, but they do exist), I think all the VQ R50s got the same four-speed auto. That one should be simpler to track down.