The digital dash in the z31 series likes to shut off while driving due to the power supply's solder getting old/hot. The process of 'renewing' the solder is actually pretty easy.
On my 84 300zx AE with 44K miles (on 2nd day of owning it) my digital dash went completely out and found a video online that explained to check the 10amp fuse for the rear wiper. Sure enough it was blown and after replacing my dashboard worked again! So if you're digital dash goes completely out be sure to check that 10amp fuse for the rear wiper first!
Thank You Soooo Much !!! This worked on my 86 300zx! I wiggled the supply and the display would come on then off ,after this it works all the time.I would of never thought of attempting to do this but your video helped me gain confidance .You Rock Man!!!
It will not. My last z had the same issue you mentioned and this repair did nothing. Apparently there is a box to recalibrate the compass and I bet it has something to do with that. If I get a chance to do some research I'll let you know if I find anything.
ShamanNoodles Sorry guys, haven't had a chance to look into this yet. Plus mine work ATM so it should be hard to troubleshoot. Check out this link to a write up on calibrating the compass, might not fix it but might lead you to something else you can try troubleshooting. xenonzcar.com/z31/CompassCalibration.html scroll down to something about multi or missing arrows. Good luck and I'll let you know if I get a chance to check it out.
I think once the metal tarnishes enough, it barely makes a connection even when they are actually touching pretty well. Next time I have an issue, I'm going to look for some small metal pipe cleaners and try to clean the metal on the pins and bracket.
Hey! Do you think adding a little bit of new solder would help? I have an '84 50th AE that I bought to get into imports, and man is it a LOT OF electronics. Thanks!
I believe it's important to avoid mixing different solders if possible. I think we're supposed to figure out which type was used, and use the same thing, or remove as much as possible and start fresh with a proper kind. I have a feeling the metal pins are creating a layer of corrosion where they meet the solder and eventually create a pocket of rust that sometimes connects when things get hot enough. So I think the idea is to turning each pin's solder liquid for a sec so it hopefully bonds better with the pin.
High quality Silver Solder will work fine... You do not want to totally take out all the old solder unless Your really experienced in circuitry ... and have a Solder Vacuum Sucker ...
Solder flux would help a lot in this situation there are a lot of videos dealing with component level board repair, good examples of how to reflow solder properly
well, when i purchased my z the anti freeze looked as if it were never changed. so as time went by and I tried flushing it, the biggre chunks seemed to have gotten stuck and clogged it. so long story short I have purchased a new one and have dismantled most of the dash, but have reached a fork in the road with getting to this part.
Your cluster is completely dead? If messing with the plug that goes into this power supply doesn't work, its either not getting power, which means the rear wiper would be out also(I think, just check all your fuses otherwise). Or the digital cluster is dead. I picked one up on ebay for about $100 and got lucky. There are some 300zx groups on Facebook that are pretty helpful with this stuff.
I have a feeling that means the digital dash itself has a bad connection or blown component for just that area. I just replaced my completely dead dash with one from ebay, and this new one's gas gauge doesn't work. I might pop it open and see if there is something loose for that area. Getting the dash cluster out was much easier than I anticipated.
@@notapplicable1047 I thought you meant the 3 gauges that are in the digital dash cluster. I don't know what controls the ones in the center of the dash, vacuum and compass. Mine used to work and crapped out a few years ago outa no where, didn't notice anything else change around the same time. I haven't been able to locate any info on them. Diagnosing my dead digital dash cluster was a nightmare.
Give it another shot, look into cleaning the old solder off and using new solder with the right components in it like flux core. My z has been sitting for years now and I had to punch the dash the other day. As long as you didn't break anything during removal and reinstall or solder something together by mistake, you should be good after trying again.
+josue396 So just your lights on the climate control are out but the climate control still works? Is the climate control digital or analog(buttons or manual sliders)? If I remember correctly, the power supply for the dash has nothing to do with climate control. Has a radio been installed/messed since you've had it? My first guess is a wire/harness got unplugged when the stereo got mashed in there( barely enough room in that area).
+Micah Coffey I got a radio professionally installed it worked fine then it just went out a few weeks later I hav a digital dash I took the dashboard off and all the harnesses were plugged in
+josue396 z31's wiring is voodoo. The Pro stereo installer 'should' have run a new main and memory backup 12v, if they did, the original Z stereo power or something else in that area may have shorted out. I would double check my fuses at this point, it wouldn't be the first time I've re-checked them out of frustration and found one blown(this usually means it's randomly being shorted out.) To clarify, what do you mean by 'is not lighting up anymore'? Does climate control function, meaning can you control air temp/speed? Can you read the display but its dark? Is it just the little green lights around the climate control panel that are out or those and the temp/fan display?
I think this is about your only option. z31.com/repairs/heater.shtml I have not attempted this before, if I get time I will attempt making a video of this process. Never mind, that's not the link I was thinking of, but reminds me. Have you tried pushing the manual override button located about a centimeter above the display? If that does not do anything when pressed, it sounds like you are missing power. If it does make the fan come on full blast, you have a loose connection or bad climate control unit.
Good video, however, you don't have to press so hard. It is heat, not pressure that melts the solder. To make the heat transfer easier, I tin the head of the iron with a little solder, and then only have to touch the solder iron to the pad and it should transfer the heat nicely and quickly. When done, look very closely and see if you created any solder shorts. You would not want to smoke it after all the work.
Yes, I noticed after using this iron a bit that the very tip of it doesn't get as hot as the sides whether adding fresh solder or cleaning with a damp sponge. I was getting annoyed having to apply so much pressure and sometimes slipping like I did several times in the video. Thanks for the comment and thanks for watching.
When Soldering , I always clean Circuit board with Alcohol,,,, light flux, and than re Do the Joints with Fresh high quality solder in my hand ,,, and Hold a few seconds till it melts ..
Great tutorial! My 1984 300ZX 50th anniversary thermostat/oil pressure/battery section just went out today. Do you think if I do what you did it would fix that? The rest of the cluster is working fine. Thanks
Someone made a comment recently about the ignition not making full contact if the key is worn out. And I remember the z31 facebook groups saying the oil/battery area tend to be related to something else. I think if we are good with a soldering iron, its worth running through these pins. I made it look a bit tougher than it is if we warm up the iron and find a good spot that actually melts the solder. If I remember correctly, the oil/battery area might go out due to issues on the actual whole cluster unit
Ya, I just melted the existing solder so it was able to make a better connection. I have a feeling the solder used in here will be different than the new stuff we can get today, and some solder doesn't mix well with others. So it's either reheat what's there, or I think we have to clean the old stuff off first if we want to use new.
@@rizot0ny1996 Sometimes this power-box works fine, but the dash itself goes bad. I've had 3 different z31's. Each had a power supply that needed this solder repair in order to work. My most recent z finally needed a dash replacement. I think there is a way to test the output of this power-box to see if it seems to be working. Otherwise we have to try other parts and see what we can get to work. I found a few dash panels on ebay for like $100. Check the fuses and make sure it seems to be getting power
Ima try that I know I’m probably bothering you big time with questions, but I did try the rear fuse from research that I’ve done it’s connected to the dashboard as well the fuse is new and that didn’t work, so exactly which fuse do I check to make sure it is getting power?
@@rizot0ny1996 I don't remember but I think it's the fuse that runs the rear wiper. I would suggest doing some research on the net to test power to this box. I remember something about testing a few pins, which is what I think made me feel better about ordering a replacement dash
Thanks for the video, I have read all about fixing these but being able to see were to solder helps a lot. It takes a lot of the fear of messing these thing up out thanks
Glad it helps. I did this to my first Z when I was a teenager and was even less careful than I was while recording this video. To be honest I think it would be pretty difficult to mess this thing up. If you are scared just stick to those first two rows of pins, I think those are the main culprits.
**** we found that the ignition key was too short (from age/use) to trigger the key in place switch. A new key did wonders for the gauge cluster to come back to life.
Thank you for sharing. I've never thought of this and it makes a lot more sense why my old one would go out from bumps etc. Fiddling with the power supply likely ended up wigging the key/ignition. Resoldering these connections likely just gave the system more juice so it could get through a little more of the key/ignition switch's play.
I'm hoping this fixes our 300! I plan to do it once the salt is off the roads. Sometimes it loses the full dash, sometimes the tach and speedo stay on but I lose my mileage/odometers. It's odd. Sometimes when the whole dash is out, the car car will shudder horribly to the point where I have to pull and let it pass...and it does pass. Everything has been checked and reflashed etc at the dealer but still has the same issue. I was starting to give up on it until I found multiple articles pertaining to this and now this video (thank YOU, fingers crossed!). It's a 1986 turbo with 19,000kms on it. Everything is original or oem parts. It'd be a shame not to get it working right.
I don't remember that shudder when it's ever gone out but I could see the engine computer recalculating for a sec because it just lost some type of info, might even be a turbo only thing. I've driven with this power module completely disconnected and don't recall any engine issues. When I have an odd random engine issue like this, I pull the kick panel from where the passenger's right foot sits off and un mount the engine's computer so I can check the read out as it's messing up. A somewhat common electrical issue in these things is weak alternator, bad ground or some kinda wacky battery. When I was young and dumb, I had a stupidly massive stereo in one of these. I gave just about every electrical system a stroke and trouble shot it over the years, once I had a beefed up alternator, a ridiculous ground cable and an optima battery, a ton of issues went away. I recently found some weird issue in the one in this video where I had to disconnect and re-run a ground to fix the headlights or something stupid and random. It made me think a lot of issues in this thing are just bad ground from rot. Keep in touch, would be a shame to see that one stay sick, what a find.
I just bought an 84 z and the engine temp, psi, and oil pressure gauges are completely out. fuel gauge works intermittently. speed and tach read fine. i tired this fix, but nothing. any suggestions?
***** Sorry for such a delay, one of my z31's did this and the Tach lines went to full blast all the time. The digital dash diagnostic should help you see if its bad lights on the dash or some kind of bad wiring. When I would run the diag nothing at all would happen to these burn out spots, I removed the dash and attempted resoldering some spots but by the time I got the digi dash outa that thing all I wanted to do was get it back in, which was impossible and the dash looked bloated after that. I just remembered a very important thing I read about these cars a long time ago. With something insane like 4 miles of wiring in this car(maybe not that much but somin crazy) it is EXTREMELY important to have a good ground to your battery, the z I had lots of electrical problems in had a horrible ground connection to the transmission and tbh I think using the car for a long time with a bad ground starts frying things.
so my dash on my 88 z31 works but its only after 20-30 of letting the car run? After 20 or so minutes, all my electronics turn on by themselves such as dash, wipers, AC, and guages? do you have any idea why that is? Maybe alternator issue right?
That's pretty odd. If they work fine after that 20-30 and never blink out or anything, I want to assume that is from some type of third party alarm system or turbo timer or something weird. I might start by finding a pin-out that shows the hot 12v coming into the dash power supply and try putting a meter on that. It's possible a bad capacitor somewhere needs time to charge up, but I would think that would get worse quickly or not work all the time.
Mine have already been unmounted in all of the Z's I've had, so I didn't even think about that part. Its two bolts and they are a pain in the butt to get to. I attempted remounting it one time and just started finding ways to zip tie it or something. Till I finally fixed the connections, I would have to remove the power supply and wiggle the connection.
My digital dash works except for the number of gallons numerical display. The one with the bars work. I did the diagnostic and it lights up. Just when in driving it didn't show the number. Any ideas?
The numerical fuel display only activates at 5 gallons and counts down from there. Have you ever run the fuel down far enough to activate the orange empty light? I believe that one activates at about 2-3 gallons. If you've had it that low and still no numbers, I would bet its the fuel sending unit under the interior carpet, between the rear wheels. I have not messed with the electronics of the sending unit but had an 84 z that had the opposite issue, no fuel bars but 5 gallons and less worked, which appeared to be the circuit board on the fuel sending unit.
I'm sure I've run it down to one bar and no numbers. And betty didn't tell me I had low fuel either. She'll tell me if I start driving with a door open or leave the lights on when I take the key out. Interesting phenomenon.
@@MicahCoffey I have the Issue of no Fuel Bars,,but numerical countdown from 5 gallons works ,and orange bar warning ... i remember going over a bump in Casper Wyoming and it has not worked since .....Where is the Circuit board on the Fuel sending UNIT ??
josue396 40 watts, why, are you having an issue getting your solder points to melt or wondering why I seemed to have such a hard time? I noticed this solder looks and acts a little different than anything I've seen, it's like it has an extremely high tin content even though I would assume the opposite in a car from back then. This iron I used is a pos and requires a lot of pressure and movement to get the heat to actually transfer to the solder.
+josue396 It's hard to say but I don't see any reason it wouldn't. The main issue with soldering is when the tip is junk or corroded. Let it get hot, and clean the tip on a wet sponge or towel. Move the tip around on the solder point till you feel it start to move. Good luck.
Although its always a good idea, I doubt there is anything to worry about here. I don't think the wiring harness has any power to it when the ignition is off and that harness gets disconnected as you remove the power supply from the dash. Don't forget the capacitors in the power supply have the ability to store a pretty nice jolt, avoid shorting anything out or touching any metal so you don't fry the unit or any body parts.
Just to be sure I did anyways. Very helpful video by the way I just finished doing the re-souder on my board and now my thermostat reading shows. Post more helpful videos
Spencer Arwood Glad it helped, feel free to suggest topics, It's a bit too cold out now but maybe a good opportunity to show how to fix the heat in my current z? lol. I have a few recorded that I did not edit yet, will try to get those up soon. Thanks for watching!
