Landcruiser Instrument cluster
Ok seem to have fixed my series 100 cluster. Started with intermittent fault in speedo, agents wanted to replace entire cluster. Sent to electronics whiz kids checked all connections, can back regular intermittent fault in speedo and clicking noise, sent in again, now other gauges misbehaving, back again, came back no fuel, no tachometer no speedo no cruise control, no range indicator. About now decide these guys don’t know what they are doing. Options send to specialist speedo repair, might or might not fix, seem to be good ones in States and Aus, not sure here in NZ, new cluster at mega bucks or try it myself with help from very clever electronics friend. Result everything working.
Faults exist in the male female connections at the back of the panel, almost impossible to access. These connectors simply don’t pull together close enough with existing bolts and the length of thread designed to prevent over tightening and also to separate connectors when unwound. Replacing these bolts tacks balls. And you could do a lot of damage if you get it wrong. The bolts are retained with star type washers which you can’t get at as they are recessed in the plastic housing. Maybe the plastic housing could be modified to provide access didn’t try that. I positioned the head of the bolt over a small piece of pipe which was supported on my vice and used a centre punch and decent sized hammer to force the bolt back out through the star washer which will get destroyed in the process. You will need someone to support the cluster while you are giving your centre punch some seriously hard hits. You have to try to avoid the shock going into the electronic board. Once you get these out you can replace them with threaded engineers screws which will give you a lot more pull on the connectors when you do them up. BUT undoing them will not separate the plugs and you cant get you hand or anything else in there to do it so you get around this by unscrewing the screw a few turns (leave the panel fixed to the dash at this stage, and then pushing the head of the screw away from you to start to separate the plug, repeat a couple of times and then free the panel fixings from the dash surround. Keep unscrewing and pushing now pulling the cluster toward you. Found it better to use overly long threaded screws as you can use the length to completely separate the plugs by pushing on them. Plenty of room for the additional length to continue out through the plug. Just suffer the frustration of endlessly unscrewing these things. OK that takes care of the bad connector issues.
Now I had problems with the stepper motors, These are cheap and can be obtained via web searched BUT the ones I found don’t have the fine small spring coils behind the needle as were fitted in my truck so despite having replacements on order we repaired the stepper motors on the speedo, fuel gauge and tachometer. Some of these might have suffered damage by my getting the bolts out as the wires in them and connections are so fine and poorly designed. You obviously need to remove the stepper motors from the board, watch DIY BRI care repair videos. Not as easy as it looks but hey you need a really good solder sucker, a very fine soldering tip and a soldering iron you can regulate the heat to a moderate level.
These motors have few small clips and you can open them quite easily with a bit of care and there is not a lot inside.
View attachment 162118
The problem is a very poor design. The pins which you had removed the solder from pierce the small plastic pieces that the two coils are wound around and are not secure within this plastic. Any movement breaks the fine copper wire of the coil to the pin. The coils and pins disconnect from the holder easily and are able to be resoldered if you are that good. Thats all there is to it. Oh yea and the tricky bit of reassembly without the bits dislodging from where they need to be. Because the motors in the LC have a spring fitted behind the needle and so far the replacement ones found don’t I am assuming that the coils and pins from new ones might be able to be installed in your originals, just swap them over.
Thanks to all those who offered suggestions. Hope this can be of some help to any who have similar problems. Despite the Toyota service agents shrugging their shoulders and posing mystified looks, including their auto electrician, this is such a poor design that my problem cannot have been a one off situation. This has to be a fairly common issue with those motors.
Cheers merry Christmas Warren
