My '99 Montero (109,000 mi) has a progressively worsening problem when the key is turned to the start position. It sounds as if the start contacts are failing to make good contact and a clicking or buzzing sound results. It always eventually makes good contact and there is no problem with starting, but if you don't turn the key quiclky or with added force, the buzzing will persist.

Has anyone had a similar problem? If the switch contacts are failing, I hope that the electrical switch section of the key/interlock mechanism can be replaced without drilling out the whole unit, but I haven't gone in to find out. Can anyone confirm?

Many Thanks

Ron

 

On my 92 there are three parts to the ignition assembly; steering lock cylinder, ignition switch, and steering lock housing. The lock cylinder can be removed from the housing by removing the plastic column covers and turning the key to ACC and pressing a lock pin with a philips screwdriver then pulling the cylinder out. The ignition switch plugs into the back of the steering lock housing. You can un-plug the ignition switch wiring connector while leaving the switch and lock cylinder in place, use an ohm meter to test the various postion and contacts continuity while turning the key. The switch is a separte item that can be replaced on it's own without drilling out the lock housing. Make sure the noise you here is not coming from the starter as it could be bad.

 

It sound like the electrical portion of your ignition switch has begun to go bad.Mitsubishi Part# MB903639 Cost about $40 bucks

 

Thanks to pc and DarkmanC for the helpful replies. I did a little more research and determined that the "buzzing" sound is comming from the Security System Module mounted below the steering column. There must be a starter relay in that module and when I turn the switch to start, that relay is cycling on and off like a buzzer. Therefore, the problem could be with the module, but I'm betting on the ignition switch unit since I can still avoid the buzzing by applying lots of torque to the key. My guess is that the start contacts in the switch are worn or pitted and that the average key twist only makes enough contact to get partial voltage to the relay coil.

I'll dig deeper with a meter to verify and report.

Ron

 

My follow up as promised -----

It indeed was the ignition switch and it did only cost $40. After a 10 minute swap-out project, the problem is solved.

Thanks again, DarkmanC and pc!

 

I just had the same problem but it would not release the Locking Mech on the Column. So I was Stuck...$600 W/O labor. Really. Does this happen a lot? or just my luck.

 

New guy here, also with ?'s/ problem w/ ignition, so Mojo you are not alone!
Done a lot of searches on this issue here and elsewhere, hoping someone can help--- I've also done some troubleshooting.

'95 Montero SR 3.5, 147k miles, owned past 6 years w/ few problems except this one that has recurred:
Gradually stops cranking w/ key, first time about 3 years ago and paid shop to fix(replaced the ignition switch); worked fine until about 4 months ago, this time I replaced ignition switch myself and worked fine til last week, when it started gradually not firing when key turned, SO---

Keeping in mind the truck will crank easily if I turn the ignition switch BY HAND with it removed from the key cylinder----

I replaced the switch, still didn't work so I swapped for another switch that also didn't work by key; next I replaced the keylock cylinder thinking maybe the tumblers were worn, neither the new nor old cylinders will start but will turn correctly from 'Lock' through 'Start' positions---relays click, lights/acc all work, etc.

Holding the switch, cylinder and key assembly in my hand, I can start vehicle---but never while the cylinder is replaced into the steering column. AFAIK there is no immobilizer/ deterrent system, but i tried the reset procedure just in case---the keyfob works fine as always. Fusible links appear good, new clean battery,etc. Switch, starter, engine all work--just not assembled and with key.

Given above, any input? All ideas appreciated!

 

When you run out of mechanical things to check and it works intermittently, go for the electrical gremlin. That is what I usually find. Maybe you have a wire in the column harness that is broken and when you have it in your hand, it makes contact but when pushed back in, it does not.

Try using an ohm meter to check the ignition switch, when it is not connected of course. Also, use the VOM to check the supply voltage to the switch, and check the continuity the wire going to the starter relay.

I HATE electrical problems, you cannot properly fix them till they fail completely.

 

just got mine back...and dropped it off 10 min's later. the tech put it back w/ the steering column at a 45 angle. so when it is staight the car turns right... HOPE you have better luck than me.

 

Sounds like your key assy hits a limit when you turn it all the way to Start but the switch is not getting fully in the Start position. When you take the switch out you can turn it farther - enough to connect the start contacts.

I don't recall if the switch is adjustable (rotation wise) but somehow you need to either get the key to turn a bit furhter or get the switch rotated counter clockwise.

In my case the contacts internal to the switch burned out so using the key would not engage the starter. But - just like your case -when I took the switch out and was able to turn it just a bit further (into the unused area of the brass contacts) it started just fine. A new switch was all I needed.

But your switch is new as well so this is a mystery. Are you 100% sure the part they sold you is correct for your VIN? If there is a way to enlargen or oval out the holes in the switch so that you can mount it a bit more twisted toward you then that might do the trick. But I can't recall what the mounting situation is so am not sure this is possible.