99 MX-5 passenger central locking problem - won't lock

crzymx · Postby **crzymx** » Mon Mar 16, 2009 2:17 pm

That would fix my problem!

Postby **Okibi** » Tue Jun 21, 2011 6:24 pm

Well i'm pretty busy and never got around to trouble shooting this properly.

A replacement lock mechanism showed up on ebay so I grabbed that. It arrived today and I went to put it in, test wired it in before I started pulling everything apart and it didn't work at all. :evil:

Had a play with it and I managed to get it to work ... sometimes. :roll:

The motor spins in both directions.

It works fine for unlocking but as soon it it's put under load then it won't spin the other way to lock the door.

Seems like a common problem so I thought i'd try and suss out a solution rather than copping out any putting in an actuator.

Could it be that the bushes inside the engine wear in a way they can't create enough of a pulse to start spinning in that one direction?

I don't know much about varistor's could it wear out in a way it only creates too much resistance in one direction? This one says "CCOR5 12V" but I can't find details online. I need someone like Liam's technical ability here.

The exposed motor spins both ways but most of the time it will only work in one direction under load.

Postby **Okibi** » Tue Jun 21, 2011 7:44 pm

Think i'm going to have a poke around the drivers side door again see if I missed something or made a mistake when I test fitted the jaycar master.

Caffeine · Postby **Caffeine** » Tue Jun 21, 2011 10:13 pm

Is it geared down? Does the motor spin the same direction for lock and unlock but a gear set determines the final direction? If so there may be a difference in the torque required to get it to spin, and if the unit draws too much current under load, only one direction might work.

I don't know enough about the mechanism to be much more help sorry!

Postby **Okibi** » Tue Dec 18, 2012 11:19 am

Started to look at this again.

I'll need to post some photos, I might head down to Jaycar at lunch to see if they can help.

The 12V motor looks similar to many hobby style ones so I might be able to replace that with a new one.

FK-280SA-20150
____ Range 10-15
____ Voltage 12V
____ no load - Speed (rpm) 12400
____ no load - current A 0.1
____ At Maximum Efficiency - Speed (rpm) 10700
____ At Maximum Efficiency - Torque g.cm 35
____ At Maximum Efficiency - current A 3.84
____ At stall - Torque g.cm 260
____ At stall - Current A 3.4

I'm a complete component novice and I cant tell if the "CCOR5 12V" or "CCDR5 12V" is a varistor or a ceramic capacitor.

I did try a typical central locking actuator connected to the central locking power and the actuator would only work in one direction, perhaps the problem is further up.

Postby **Okibi** » Tue Dec 18, 2012 11:20 am

ImageUploadedByTapatalk1355790029.922151.jpg

Postby **Okibi** » Tue Dec 18, 2012 11:21 am

ImageUploadedByTapatalk1355790080.629565.jpg

Postby **Okibi** » Tue Dec 18, 2012 11:35 am

mmx005 wrote:i had the same problem, there is a small switch in the drivers door (i think its at the bottom but not sure cos i did it a while ago). i replaced that with an item from jay car and its been fine since.

I hadn't seen this post, I wonder what switch? I cant remember if there's a child lock switch in the door.

Davidzferret · Postby **Davidzferret** » Sun Sep 01, 2013 8:20 am

Okibi wrote:
I'm a complete component novice and I cant tell if the "CCOR5 12V" or "CCDR5 12V" is a varistor or a ceramic capacitor.

That looks like a "PTC" Positive Temperature Co-efficient variable resistor, effectively a self-resetting thermal fuse. Resistance goes high over a certain current level. This would make sense for the application as you said it's in series with the motor.

I'm trying to sort a similar problem in our 99 NB. The difference is both doors will lock and unlock on the key, but passenger won't lock on the remote only unlock. So far I've only cleaned the connectors in the door jamb, slight improvement but I think there must be an iffy connection somewhere else, probably under the dash, dropping the actuator voltage.

I see this thread has been quiet for a while but it has been a helpful start for me; will come back with any questions (or maybe even answers!)

Postby **Okibi** » Sun Sep 01, 2013 2:49 pm

That's exactly the same problem I had (I ended up replacing the entire unit - thanks Lou).

It seems the mechanism can get stiff and that's burning something out, keen to see what you can find as a solution.

Davidzferret · Postby **Davidzferret** » Sat Sep 14, 2013 9:44 pm

Mine now works properly with no further attention since cleaning the connectors in the door jamb. But the weather is quite a bit warmer and I think that is freeing up the mechanism a bit. I'll bet the problem returns with the next cold snap. Haven't had time to dig into it any further than that.