Need Help With Stihl 015AV On/Off Switch

[Walleye Guy]

I inherited a Stihl 015AV from my grandfather when he passed away a few years ago and the on/off switch isn't working so you have to turn on the choke to shut it off.

I remember using this with my grandpa in the 80's when I was in grade school and that's what we did back then too.

How is it supposed to work? Does it connect to ground to kill the spark?

The contact that the switch touches appears to be worn.

Maybe part of the metal strip on the switch broke off?

See attached pictures of the switch and contact.

Thanks in advance for any help.

 

[pioneerguy600]

That contact spring needs to contact a metal surface of the engine crankcase or the metal housings, contact patch needs to be bare clean metal, many of the older Stihl saws used similar switches. Contact area must be completely dry and clean like any switch contacts to conduct electricity to ground out the coil.

 

[Walleye Guy]

pioneerguy600, I removed the switch and, using my multimeter, I checked for continuity between the contact shown in the picture (is that the coil?) and the outer case. My meter beeped indicating continuity. Is it supposed to be that way? I would have guessed there isn't supposed to be continuity between those two points and when the switch connects them then the engine dies.

 

[pioneerguy600]

pioneerguy600, I removed the switch and, using my multimeter, I checked for continuity between the contact shown in the picture (is that the coil?) and the outer case. My meter beeped indicating continuity. Is it supposed to be that way? I would have guessed there isn't supposed to be continuity between those two points and when the switch connects them then the engine dies.

I am not sure how you are conducting your test but that is what a switch does, when closed the switch completes the circuit and grounds out the coil. It does that in this case when the metal spring part contacts the metal portion of the saw, closed or saw off position, when the contact is not touching a metal part of the saw ,open contact, then the coil is not grounded and allows spark to the plug. This is a slider switch is it not?

 

[Walleye Guy]

pioneerguy600, thanks for your response and sorry if I wasn't clear...let me try again. Yes, I understand how a switch works Here is what I did: I removed the slider switch and then set my meter to check continuity. I put one lead on the outer case and one lead on the contact (is this the coil?). The meter beeped which indicated yes there was continuity between the contact and the case. I was surprised because I thought there shouldn't be continuity with the switch removed.

 

[pioneerguy600]

The contact is not the coil and your test does not make any sense to me at all. With the switch off the saw and the test leads connected as you say there would be no way there could be continuity. electrical current has to flow through the switch to get to ground on the saw case.

 

[Walleye Guy]

It didn't make any sense to me either so that's why I posted it. Let's start here: what is the contact that I showed in the picture? What component is that?

 

[pioneerguy600]

In your pics, I see two pics of a switch mechanism and one pic of a part of the chainsaw engine. Can you follow the sparkplug wire back to the coil ? Once you find the coil there should be another smaller gauge wire connected to it that acts as the ground out pathway, that wire needs to connect to the switch somehow. Post a pic if you can and I/we can help with the connections necessary to make the switch work correctly. There needs to be a pathway between the coil and ground through the switch to get this working properly.

 

[pioneerguy600]

Here is a You Tube vid that will show you where the coil, which is actually a module in some 015`s, the module is a coil that contains the electronic switch within it and it therefore does not need points or condenser for operation as a coil did need.

 

[Walleye Guy]

Thank-you for that reference, I'll watch it this weekend sometime.

 

[pioneerguy600]

Unfortunately he does not show the wire that connects to the switch but is there and he does mention it but not show it. I have to presume the wire is there for your saw and just needs to be reconnected to the switch , once the wireis connected that will complete the circuit needed to ground out the spark when the switch is activated moving the ground strap down to engage bare metal. best of luck on getting your 015 operating properly again.

 

[stihltech]

The contact connects the wire and the case (ground )to shut the ignition down. Most common issue on an 015 is the loss of contact at the case from corrosion. I use a small screwdriver bent at 90 degrees to scrape the case and also with a small piece of emery cloth to shine it up. Occasionally the small brass piece that holds the wire in the rubber grommet will lose contact. Clean it and use a litle solder to regain continuity. Had to do this to almost every 015 that came in the shop. Make sure the top of the contact that meets the case has tension on it.

 

[Walleye Guy]

Sorry for my delayed response. I don't think there is a wire in mine. I can remove the switch and I see how one part of the tab rubs on the case but there is no wire going to the switch. I was under the impression that the other end of the tab rubs up against the terminal shown in my pictures.

 

[pioneerguy600]

Sorry for my delayed response. I don't think there is a wire in mine. I can remove the switch and I see how one part of the tab rubs on the case but there is no wire going to the switch. I was under the impression that the other end of the tab rubs up against the terminal shown in my pictures.

That may be a possibility but that terminal then would need to be connected to the points or coil by a wire or some other form of pathway for the elec to be grounded out. You may have to remove the flywheel to see if the components under there are still connected. Some of these 015`s used points condenser, some coil and separate spark modules and later ones became electronic versions thus making the on off switching different. Around the 6 min mark in that vid I posted shows the wire running up from the points toward the on off switch, that wire may be disconnected, or corroded preventing contact between the points and switch. Visual inspection is needed.

 

[AoxoMoxoA]

Hope this helps...

Be aware, that the underside of the chassis the switch makes contact with, must be clean and conductive, and the lower tang must simulteneously make contact with the "nub" you have pictured, for the switch to work. Over time, both surfaces can get dirty, preventing the connection from happening. In your picture, the "nub" contact looks good, so I'd focus my attention on the underside of the top chassis the switch slides into, to make sure the top tang is contacting clean bare metal, then make sure both ends are contacting their respective contact points (top & bottom) when the switch is slid forward, into the OFF position.

 

[AoxoMoxoA]

I was under the impression that the other end of the tab rubs up against the terminal shown in my pictures.

It does; see my post above. The metal tang connects the chassis to the terminal (grounding the coil out) when it's slid forward.

 

[pioneerguy600]

It does; see my post above. The metal tang connects the chassis to the terminal (grounding the coil out) when it's slid forward.

If both the case contact area is clean and that terminal clean also then the likely area that is not connected is under the flywheel, I did recommend looking at the video around the 6 minute mark the wire connection s shown.

 

[Walleye Guy]

pioneerguy600, I noticed the wire when I watched the video over the weekend. To the best of my knowledge, that wire is not on my saw. I'm not sure if it never had it or if it was removed.

AoxoMoxoA, I have not checked for corrosion where the slider switch contacts the case. I'll check into this. Thanks for confirming that the "nub" connection point looks good to you.

I still don't understand why my multi-meter showed continuity between the nub and the case. Based on the responses above I'll have to recheck this to verify I saw what I reported I saw. : )

 

[pioneerguy600]

pioneerguy600, I noticed the wire when I watched the video over the weekend. To the best of my knowledge, that wire is not on my saw. I'm not sure if it never had it or if it was removed.

AoxoMoxoA, I have not checked for corrosion where the slider switch contacts the case. I'll check into this. Thanks for confirming that the "nub" connection point looks good to you.

I still don't understand why my multi-meter showed continuity between the nub and the case. Based on the responses above I'll have to recheck this to verify I saw what I reported I saw. :

pioneerguy600, I noticed the wire when I watched the video over the weekend. To the best of my knowledge, that wire is not on my saw. I'm not sure if it never had it or if it was removed.

AoxoMoxoA, I have not checked for corrosion where the slider switch contacts the case. I'll check into this. Thanks for confirming that the "nub" connection point looks good to you.

I still don't understand why my multi-meter showed continuity between the nub and the case. Based on the responses above I'll have to recheck this to verify I saw what I reported I saw. : )

Have you had the flywheel off? The ground out wire is located behind the flywheel so you would need to remove it to check on the wire condition. The guy in the vid shows that wire at exactly 7.18 mark onward a bit, one can see the wire and that small brass terminal at that point in the video. IN the other thread you have going Harley posted a IPL for the 015 and in that # 16 is the ground out wire you need to locate.

 

[AoxoMoxoA]

AoxoMoxoA, I have not checked for corrosion where the slider switch contacts the case. I'll check into this. Thanks for confirming that the "nub" connection point looks good to you.

I still don't understand why my multi-meter showed continuity between the nub and the case. Based on the responses above I'll have to recheck this to verify I saw what I reported I saw. : )

Yes, check that there's clean metal under the case where the metal top of the switch makes contact. As stihltech mentions in post #12 above, a corroded or dirty inner case surface is a common fail point with these saws. It was on my 015L and also with a friend's 015 which I repaired.

Your multimeter showed continuity between the nub and the case because there IS continuity between the nub and the case when the switch is in the forward "stop" position. That continuity (when the switch bridges the gap) is what grounds out the coil, killing the spark.