speedo/cluster repair problem

[hkz286]

Hello all,

I’ve had an issue with the brake warning lamp on my car since I bought it. Having grounded out the rear taillight pin as per the service manual, the lamp remained on. So I figured it was the cluster/dash that was at fault and upon looking at other people’s cars, it looked as though the capacitors leaked over the chip that controls the warning lamps.

I contacted kaz to see if he would repair it, and whilst he said he would, he also said that the tacho and speedo will probably be out of calibration afterwards so would need recalibrating. The only people I can find who do this is T3TEC in Japan. As I don’t speak Japanese and I don’t know anybody in japan, I thought this option was problematic.

However, having looked over a few post, it seems that there have been a few fires in regards to the capacitors leaking, and whilst unlikely, it still worried me. I thought I may as well go ahead and replace the capacitors to eliminate the risk of a fire, and made peace with the fact the warning lamp would still be on, and the speedo and tach will not be correct (but I won’t be set on fire :p)

So I go ahead and replace them all with the correct spec and clean off all the damage done by the leaking capacitor (there was only one).

Put everything back together, switch it on and suddenly the temperature gauge suddenly goes to maximum. Now the speedo and tach are working perfectly (verified with gps and external rev counter) which is more luck than judgement and the warning lamp is still on (the chip must have been damaged) however the temperature gauge is all wacky.

Now I went about this very carefully, one at a time, verifying the polarity of each capacitor and the spec and replacing one by one. However I will be taking it apart again to double check I haven’t done anything silly.
Before I do this does anyone have any idea why the temperature gauge would always sit at maximum after I changed the capacitors? I know the calibration of things could be out because of the tolerance of the capacitor but I didn’t think it would be this dramatic.

Any help would be appreciated.

mike

[unclebob]

if you removed the guage from the cluster then i reckon you tightened one of the screws too much when reinstalling it and broke the terminal at the other end. you can see two small wires which attach to the circuit board via the point where the screws tighten the guage to the board, if one of these is snapped, your guage will go to max or not work at all

[hkz286]

if you removed the guage from the cluster then i reckon you tightened one of the screws too much when reinstalling it and broke the terminal at the other end. you can see two small wires which attach to the circuit board via the point where the screws tighten the guage to the board, if one of these is snapped, your guage will go to max or not work at all

after trawling though old post I came to the same conclusion, hope it's an easy fix :S

[Hagasan]

Just a guess here.. Could you have replaced a screw without an insulating washer and shorted a connection causing the needle deflection?

[hkz286]

thanks for the suggestions everyone.

I found out what was wrong. It is indeed a broken ground. On the actual gauge itself the wire has come apart from the post. Trouble is the post is used for the mounting the gauge, and the entire thing has become brittle and cracked with age. Therefore when i tightened the screws, the post rotated, pulling the wire loose from the copper windings on the gauge. I could solder the wire back in place but have no way of securing the gauge. I'm going to need a new gauge now i think.

thanks for the suggestions :)