Some electrical dash problems...

[CDE]

Hello!I am just a new proud owner of a 1989 late make 240SX with 176,000KM (NOT miles). I got it for a steal because it needed new tires, new batt, and the dash was pooched. I am having some major issues with the dash. The previous owner said it stopped working "a while ago", so Lord knows how long that is. The backlights don't work, the odo and trip meter don't work, the temp gague works sometimes...really the only 2 things that work OK are the Tach and the fuel gague. Has anyone encountered this problem before? I did a quick breeze through the forums to see if there were any similar problems, but they did not say exactly what was wrong and how to fix it.

When I drove the car home from the dealer, the electronic speedo came one as well as the HUD. it kind of flickered on and off for a few minutes and then after a few whacks to the dash and I also fiddled with the needle that changes it from kph to mph and it stayed on the entire trip home (about 2 hours...crappy traffic). But it hasn't worked since.

Do you knowledgeable Nissan dudes know what's going on? Possibly a dimmer switch, or should I just rip the dash apart and try to find a messed up wire, or clean all the connections on the circuit boards... Someone in another dash issues thread mentioned a TCU..what is that?

Thank - you for trying to help
Modified by CDE at 12:11 AM 1/24/2005

[s13sr20chris]

that sucks, you will most likely have to view each gauge as a separate system as it does not sound like a power or ground issue(though it could be). i would first reccomend pulling the gauge cluster out and checking for corrosion on the circuit board. its very easy to take apart. and...

welcome to nico!

[CDE]

Thanks!

I had it apart this morning and checked the back of the gauge cluster to look for something dodgey...but was unsuccessful. Unfortunately I didn't have time to dink the the wiring more and check everything more closely, but I was pressed for time. But something interesting happened...after I put everything back together, only 1 little thing changed.... The little clock that is just below the tach, well, that used to never have light to it when I had my lights on during night time, but now - the light on the clock works, and my rear tail lights have stopped working. I didn't have time to check the fuses because I was already on my way home (visiting the folks 3 hours away).

I'm thinking that maybe something is botched in the main harness were all the gauges and other switches plug into. I know all the fuses I checked were fine, and all the bulbs seem to have life still in them. After I dropped the steering column, everything was easy to see and to get at. Sometime this week I will go at it again and take more things apart to check for corrosion and anything out of place. I didn't totally take apart the cluster panel; I just popped it out and looked at the connections.

Things that work on dash: Tach, fuel, and occasionally the temp. gauge, the hazards, rear defrost, all LED warning lights and signals...

Things that are not working: electronic speedo and HUD, cruise control, odometer, trip meter, all background lights, and I think that's it.

Any ideas at all? Is a botched dimmer switch likely at all?

[s13sr20chris]

yes, the dimmer switch is a common failure. you can remove the dimmer and jump the signal wire to the ground wire and that will be like the dimmer is full on.

[CDE]

Just thought I'd post some thoughts.

As I said before, after I had my dash apart, looked at everything, put it back together....then 2 things stopped working (on top of everything else not working already), and then 1 thing started working. I think something in the light switch on the signal rod is messed as well as the main harness or something to that nature.

Where are the grounds located for this electrical? Is it in the dash, or engine bay? I just wanted to try that before I do anything more extensive to my dash. I haven't had much time to do anything because I'm a nursing student and don't get to have much spare time for anything...even sleep.

[dans240]

sorry to barge in... last night after having some work done on my 92 240, suddenly my clock doesnt light up!

do you know what you did to get yours working? EVERYTHING else works fine... pretty unusual for 1 thing to go on its own... if it was a fuse, the other accessories on the same fuse would be out as well!

[CDE]

AH! You're lucky it was just your clock, dan

I'm not really sure what happened. My clock light did work, but not when I turned on my lights. Now, when I turn on my lights it works, but now my driving lights don't work. SO frustrating.

I was going to ask Chris a question, or anyone that may know....

Where are all the grounds for the inside electrical on this car located?

I'm ready to kick the bucket, and take it in to an electronic specialist, but I'm broke and wanted to at least attempt to fix it myself.

I had the dash apart and all the connections are un-corroded and in good shape. There is also nothing wrong with the PCB's in the dash. It has to be a fudged connection somewhere....

[s13sr20chris]

there are many chassis grounds. you usually have to pull a few panels(esp the drivers knee bolster) and look around. they will be all over the place and they may or may not be redundant.

[CDE]

Thanks, I shall have a look. I just left most of the panels off from last time I was working on it...

[amolao]

sorry to barge in... last night after having some work done on my 92 240, suddenly my clock doesnt light up!

do you know what you did to get yours working? EVERYTHING else works fine... pretty unusual for 1 thing to go on its own... if it was a fuse, the other accessories on the same fuse would be out as well!

Check all fuses again....on the kick panel driver side......are your seat belts working properly??? I had the missing clock issue one time and it was a fuse, also affected the seatbelts....cant remember the name of the fuse now...

[amolao]

There is a good chance that your HUD display module is bad.....http://multi-index.myonlinesit...o.htm

and the other problems sound like you have a bad PCB on the back of the cluster.....check for broken tracks or damaged components....the trip meter and odometer work with different signals, and having a bad HUD module will not make a difference, so that makes me think you also have wiring issues(wiring harness)......you mentioned that the PCB looks good, but you might have bad diodes......THere also a good chance that somebody worked on the cluster in the past........is a lot of things to check but take your time and for God sake, do this on a weekend where you can take your time and not be rushed.... Pull the multimeter out and download a copy of the FSM, they are your best friends.......

[CDE]

There is a good chance that your HUD display module is bad.....http://multi-index.myonlinesit...o.htm

and the other problems sound like you have a bad PCB on the back of the cluster.....check for broken tracks or damaged components....the trip meter and odometer work with different signals, and having a bad HUD module will not make a difference, so that makes me think you also have wiring issues(wiring harness)......you mentioned that the PCB looks good, but you might have bad diodes......THere also a good chance that somebody worked on the cluster in the past........is a lot of things to check but take your time and for God sake, do this on a weekend where you can take your time and not be rushed.... Pull the multimeter out and download a copy of the FSM, they are your best friends.......

Thanks dude.The link is awesome...if its just the diode. I had some more time the other day, but to my neglect, I realized that I don't have a multimeter...I used to have one, but have moved and don't remember unpacking it.

Like I said before, Ithe cluster worked for a few hours on the trip from the dealer, but did not work the next morning. I scored a full mechanics guide and electrical schematic of my 240 off of ebay so it will be nice not to have to search very long for what I'm after.

Thanks for the tips. I will post when I get somewhere...or get stuck again.

[CDE]

ok, the driving lights turned out to be 2 shot fuses...

so its just the dash again.

Also, now my clock isn't lit up when I turn on my lights...its like the fuse reverses its poarity or something...