Porsche Problems: Electric Trunk Latch BUSTED? ('84 928S)

all right part three of the Porsche 928 s I'm gonna fix the brakes we fix the headlights now the owner wants us to fix the trunk so what's going on with the truck he said it latches but it doesn't really latch very well you can just pull on the lid it'll pop right up that's not correct um it does have an electric trunk release on each side there is a little pull button you pull it you hear something activate in the trunk but nothing happens back there so how is this thing supposed to work well this thing to do is read the owner's manual pretty cool that we have the original owner's manual here let me pull up the information on how the trunk is supposed to work and then we'll diagnose it and hopefully repair it with minimal parts I love reading old owner's manuals you don't see this uh in today's cars anymore look at that that's just so cool we're looking for trunk no oh tailgate no how about doors door locks 12 to 13. switches even has a little lit up switch so we have a s key auxiliary key doors doors doors interior lights that's another one of the customer complaints is the uh the dome lights no nice lady from the 80s driving a stick shift very classy here we go B that's the uh released a parking brake hatchback release okay with one or both doors open you can release the hatchback by pulling either button B on the left of the driver's seat or the respective button by the passenger seat the hatchback will open automatically also see hatchback oh I'll just keep going through here I guess you get this thing with an automatic I don't know why you would clock doesn't work the sunroof doesn't work [Laughter] where's the hood the glove box luggage compartment roof racks washers don't work customer wants us to address that it has an intensive windshield washer system that's pretty neat special silicone remover so it has two separate washer systems fancy pants all right let's just look up hatchback here there's the fancy fuse box that we dealt with lights oh let's see displacement compression ratio design Powertrain curb weight 3 300 pounds okay climbing performance ooh maximum speed 146 miles per hour under seven seconds to 60 I want to give acceleration curves manual gearbox this is the coolest owner's manual ever no I guess that's it a hatchback release 48 let's look at 48. and we were close alarm to open see hatchback release or insert the master auxiliary key into the lock and turn clockwise hatchback Springs up slightly to close lower hatchback and just push it down see hatchback release 23 I think we were just there yep we already read that so that's how it's supposed to work um pop it open do a visual inspection on it and just logically can I go through the procedure all right so here's what we have so on this side we have the keyhole and we have a little plastic detent I do see that this whole assembly has a crack in it that's not good down here we have this big push button and I think that's just the assist to let the trunk pop up a little bit and here we have this electric motor with a rod adjustable I guess has three wires and inside the latch there's like I guess the rods attached to that silver thing so what happens when we pull pull the button all right I'm going to pull the button we'll see what happens on that latch mechanism [Music] so that thing Moves In and Out and I assume that it's supposed to just push this plastic and the trunk you know will be able to release why is the motor only running when you have the button pulled up I assume that by design should work pull the button up it'll cycle through open the you know trunk and return back to its original state where that little metal bar should be in it's only supposed to come out once and retract and then your trunk will be open this thing is just cycling as long as you hold the switch up that's not correct I don't think so for that let's take a look at the wiring diagram see what these three wires do what they're supposed to do just get a test light check those out um but that's you know that might explain why it doesn't stay latched if that silver thing is retracted all the way or you know out and then the I don't know all right tailgate unlocking Drive so three wires and you know I did some preliminary tracing so blue is ground goes here here here to U2 and in our master big sheet here we go to connector u 2 and then see it comes from d23 up goes to Z5 and Z5 that is a ground point right there so these are all ground points okay now what are the other two wires on pin four there is it comes from V5 right here and V5 V 5 from G24 that is fuse output 15. and fuse 15 is right here and that's terminal 30 hot at all times so we should have a constant power I don't know what this is it might be an inline fuse of some sort and then the third wire comes from our buttons now the buttons again two wires one comes from F4 and they're symmetrical left and right buttons and then when you push the button that connects F4 to the motor on that third wire so what is F4 f 4 looks like fuse output from 23 also goes to A8 so fuse 23 yep inside light clock tailgate unlocking so that's cut at all times A8 is right there F4 jump to j11 so that I guess feeds other stuff we don't really care that should be hot at all times so when you push the button it sends power to the third wire on this tailgate unlocking drag so what I think should happen by Design is you push the button this wires momentarily energized and this thing is supposed to turn whatever 360 Degrees to do one full cycle and then stop on its own that's why we need this constant power feed for that cycle to complete right now it's only turning out when you're holding the button so let's do a test light check whatever this is and see if we can get at least this tailgate unlocking drive to act appropriately all right so this indeed this red wire it does look like there is a glass fuse in here and once you know it it definitely looks blown so I do have some of these in stock it's a mini I don't know this one says doesn't really matter this thing can't it says 5 amp on it let me try to get a replacement we'll pop it in here see if anything changes I've got one in stock here one amp 250 volt fuse Slow blow now I just want something to fit in here I'm not gonna fry anything this is already on a fused circuit so as long as it fits I'll be happy whoa okay so I think the motor returned to its original state that's what it sounds like see the little latch is now fully retracted and I bet now when I pull the button just momentarily that's one full cycle well that's cool okay did anything change let's try it close the trunk latches can we still pull it open yes will it unlatch with the electrical Gizmo no okay so I guess that was a problem but not the problem what else could it be is there something mechanical that's going on here you know I know that's turning now it's doing a full cycle for some reason it's not depressing this plastic not unlatching the trunk now it looks like here that the actual alignment is crucial because you know when we close it kind of hard C but if this part is too far away from that little push mechanism you won't do anything and you kind of see here that has been rubbing on the back side and you know this crack is here it's kind of lifted up a way from the body so this thing is tilted this way obviously a little electric release won't won't work and it actually won't latch far enough to turn off the dome lights I noticed that if this is in the dome lights position so we close the door now if I push this button I have to push it all the way down to turn off the dome light if we just close the trunk latch it you guys can see the dome light in there I have to push the trunk close a little more to get that light to turn on and the body Gap is pretty big so you have to it has to be there this thing indeed is not latching all the way I think because this thing's messed up so let me pop it off let's see what the heck is going on in there maybe shim it out I don't like this crack hmm all right let's uh undo that these out of here okay okay so there's a wire there that's for the automatic door lock system which also doesn't work surprise surprise and there's our HELOC cylinder now why would this thing be tilted back like that surface is still pretty straight that's cracked that's not a good thing um it looks like the mounting buses here is just thin sheet metal and over time see the nut is kind of bent this way this is bent this way so the whole latch is tilted out and obviously that's and leaves that's why it doesn't work very well so could we somehow straighten this out either put a bolt in here and just gently tweak it just straighten out this sheet metal I mean we could hit it here with a a little gentle air hammer to tilt that in hmm I don't want to snap that welded nut off and let me see what we can do here all right so I'm going to gently try a little piece of metal here put that here and just bump this with a air hammer see if it moves okay okay now it definitely tilted in that way I think that worked like a charm let's try this side okay mostly straight it's mostly straight I'm gonna try to refit the latch and see if it latches any better all right so latch is repositioned let's tighten down these bolts so you can see that Gap closed right up against the trim so this thing is definitely tilted in more now let's see if it works oh I like it so the dome light is still a little finicky let's see if the electric release now works or not [Music] um oh I tried it's so close still not quite but I can't open it with my hand anymore so that was an improvement try again so now we have to use the key to open this thing okay that works so we're close [Music] um next step I made a couple shims you can unscrew it and kind of put them here to tilt the latch even further that way I know we're getting close try number three yes so what I did was I took the air hammer and I I just hammered this a little bit in to kind of realign it see the crack is obviously still there but now hey let me close the door and close the trunk the dome light goes out the Gap is pretty flush and [Music] that works so not a long term fix but proves the concept he needs a new trunk latch assembly that's not cracked that'll definitely fix the problem easy to replace while the lock cylinder might be you gotta swap that over but that's another customer complaint resolved no parts required at least for now um I don't know if he wants me to keep going the front washer system is kind of a mess broken lines and stuff I want to take this thing for a test drive once the weather improves a little bit all right so I talked to the owner about the Porsche gave him a progress report and we got the rear brakes figured out we got the headlights figured out we got the rear trunk latch figured out for now um I asked him do you want me to keep going he's like yeah uh he wants it basically as close to stock as possible with every all the accessories working let's take a look at the list of accessories that are still having issues so um front wheel bearings are loose I'm going to tighten those up then front washers plastic fittings are broken spring green fluid instead of blue fluid so take care of that dome lights on the rear lid they're not working when the lid is open only when you manually energize it on Hazard switch is messed up so we'll need to order a new one of those that cannot be fixed no parts required unfortunately the sunroof motor it tries to move but the sunroof does not open so it's mechanically stuck the clock the minutes display is messed up I don't know if that can be restored with a soldering iron or not power locks uh work somewhat from the center control button but I can't turn the key in the driver's door and they don't activate uh silicone spray system for the front windshield we're not going to worry about that and the radio he wants to find an oem radio and then get the antenna working that's further down the road so let's adjust these front wheel bearings the procedure looks pretty straightforward just one nut to set the preload and then we'll move on to the washers all right so here are the front wheels and the check for Bear you know for any play you want to wiggle the wheel this way you can hear that the bearings themselves have some slop you should have no slop but this should spin freely so let me pop the wheel off we'll see what the adjustment looks like this axle hub cap is being pretty stubborn so I don't want to damage it I'm just holding it with these pliers and [Music] trying to tap it out it's definitely coming ah yes Okay so we have a nice goopy bearing in here it looks like they were freshly packed with grease or installed obviously the adjustment just needs to be tightened up a little bit now there's a locking bolt right here and there's actually a cut out in the hub so you can get an allen key in here and then you see that's moving so let me loosen this up and we'll just snug it up a little bit six millimeter that comes loose all right now we can see that turns so while spinning the bearing I want to turn this see that's just the lock nut I want to turn the actual okay so that's the thrust washer there so you want to keep turning this fill them bearing has no more play but it still spins freely okay right about there should do it just finger tight yeah I like that let's tighten this up so there's the rotor on the Hub but the Hub doesn't move anymore nice and smooth I'll call that just about perfect it's back in [Music] good enough okay do this same thing to the other side this is what a well-adjusted bearing should feel like no noticeable clunking or slop but still it's been super free

Channel: Pine Hollow Auto Diagnostics

Views: 36,446

Keywords: Porsche, Trunk, 928, fast, trunk, release, malfunction, broken, repair, DIY, diagnostics, latch, electronic, motor, fuse, wire

Id: 8nGU1H-LHcQ

Length: 27min 10sec (1630 seconds)

Published: Tue Aug 15 2023