cluster replacement

[schaefer]

hi everyone, i own a 1992 mazda protege lx 1.8L DOHC and have a problem. i recently had to replace the mileage counter assy. to replace the vss inside. when i took the cluster apart the temp. needle came off. i just replaced the needle, aimed it about a 1/16 of an inch below the cold level where it was before, put the cluster back in the car and as soon as you turn the key, the needle spikes all the way hot. i have had this thing out 4 times already and really would appreciate any help at all as to why this is happening. the gauge worked fine before and the temp. sensor was replaced about 4 months ago. thanks.

[schaefer]

hi everyone. i tried moving the needle on the gauge again and this time it is only going up about a 1/16 of an inch above the cold mark. i also noticed that the speed is incorrect. the car goes faster than what the gauge says i would say about 5-10 miles per hour difference. the RPM's and gas gauge are correct. i did not notice if the car i took it from had 13 or 14" wheels or if it was single or dual overhead cam because the motor was already gone. mine has the 14" wheel option and the engine is DOHC. would this make a big difference as far as the gauge cluster is concerned?

[bcowie]

hi everyone. i tried moving the needle on the gauge again and this time it is only going up about a 1/16 of an inch above the cold mark. i also noticed that the speed is incorrect. the car goes faster than what the gauge says i would say about 5-10 miles per hour difference. the RPM's and gas gauge are correct. i did not notice if the car i took it from had 13 or 14" wheels or if it was single or dual overhead cam because the motor was already gone. mine has the 14" wheel option and the engine is DOHC. would this make a big difference as far as the gauge cluster is concerned?

what size 14's?

[schaefer]

195/65/14

[Mazda_Powered]

I would just source out another cluster instead of repairing yours, definitely sounds like it could be the issue...

If you hadn't messed with the cluster and the heat gauge instantly shot up, then yes, there'd probably be something wrong with the temp sensor or the wiring..

[gofanu]

Tires 155/80/13, 175/70/13, and 185/60/14 are the original sizes on 323/Pro and they are all the same OD, so all the speedo calibrations are the same. 195/65/14 is 12.5% bigger, so your speeds/miles will read that much low. I have 195/60/14, which are theoretically +2%, which is about the top side of normal speedo error and within treadwear variation. My speed and mileage readings usually match radar signs and mileposts exactly. But I gotta be real careful with my winter 185/70/14 at about +7%. maybe more for the studded snows - certainly the radar warning I got last winter was higher than the speedo reading at the time. Manufacturer and tread design can vary about +/-5%

FRM

[schaefer]

that is strange cause i never had a problem with the speedo until i replaced the mileage counter in mine. as far as the temp goes, i hooked the wiring up to the cluster without the cover, turned the car on and, when it was already at normal operating temperature installed the needle right in the middle. i know it is still not accurate. is there a way to calibrate it?

[gofanu]

I don't know what to tell you about your speedo, and I don't know exactly what you changed or how it is made inside; the calibration is quite delicate. By tire size alone, you should have been going about 12.5% faster than it said, before and after your "fix". That would be near 6mph at 50mph; 50 indicated would be 56 actual with those tires, give or take the particular tire variations from the ones I looked up and treadwear. Are you certain that you actually ever checked it before the repair?

Temp Gauge calibration is a waste of time, since the gauge does not actually tell you the temperature. Most cars with ECUs now fiddle with the temp readings, and some with oil pressure readings. You will notice that these Mazdas normally go up to a fixed point and stay there all the time, only going high when something is really wrong. All my cars stay at the exact same place once warmed up, unless there really is a problem; I've had one out of four cars go towards high one time - had low water from a cracked rad. Even on 100 deg days when the fan comes on, they say the same thing as when they just get warm in the winter when it is zero out. I actually measured coolant temps and confirmed this, but I did not test enough to get the actual range for "normal", and it may vary by other readings. It is likely something like 10 deg below stat opening to 10 deg above fan switch in, maybe more, say 180-215. Remember that the ECU is getting more than one temp reading. The reason being that the car companies got tired of people taking every little deviation on the gauge as meaning disaster. (Some people call the gauges "worrymeters") Jaguar did this with oil pressure, since people constantly complained about low pressure at hot idle, so they just made it read in the middle if it was in the normal range for the operating conditions. I assume the ECU compares engine temp with RPM and actual OP, and decides if the oil pressure is OK, then it tells the gauge to stay at "normal".

FRM

[schaefer]

ok, i just wanted to make sure that the slight abnormality with the speedo reading did not cause any damage to the vss i just replaced. thanks for the info.

[schaefer]

hey, well i really don't know what to do with this thing. i was driving the family to the store today and on the way home the "hold" light on the cluster started blinking and the transaxle would not shift from second to third. i replaced the vss just about a week ago. what do you guys think? should i try another cluster?

[schaefer]

hey, i thought i would post some pics of exactly what is giving me this problem. i had to unscrew the vss from the mileage counter.

[schaefer]

hard to believe something so small can cause such a problem. anyone know where i can get one of these?

[gofanu]

That VSS looks like it is just a reed switch, which is a pretty bulletproof thing. How and why did you decide that it is bad? You should be able to tell if it is working by reading resistance across the two leads, zero or open. It is actuated by a little magnet on the rotating bits; is the magnet there?
I'm inclined to believe that you have a connection problem somewhere, maybe where it interfaces with the PCB, or possibly in the ECU wiring.

I don't think the "Hold" has anything to do with this either. "Hold" should keep it from shifting up from whatever gear it is in when you push the hold button, so if you pushed the button in 2nd, it would not shift up to 3rd. Been a while since my auto died, but I think it cancels hold when you shut the car off, so it would appear to have repaired the problem. If you did not push "hold" and it went to "hold" mode, then you have a wiring problem in the shifter system, or again going to the ECU.

FRM

[nerd racing]

My 4wd protege runs that much off with the exact same tire size. It always has... my winter tires run off too at 185 70 14's.

[schaefer]

hey. the car goes into the hold mode while driving for a little while by itself. it is not like the normal light that stays on when you activate it. the transaxle will downshift to second gear at the same time the hold light will flash. i retrieved a code from connecting a jumper to ten and ground terminals on the diagnostic connector in the engine compartment. only after the hold light flashes it sets a code 6 by which i was told by a trans shop was the vss. but, the wiring does sound like a place to check next considering i already replaced the cluster twice. the magnet and all the other parts are there and when i test the connections on the cluster and the vss i do have continuity so i guess the next step is the harness. it is strange though, it only does it after the engine gets hot. i will post anything i find. thanks.