P80 Ignition switch, Electrical part, 9447804 Root Failure Analysis Topic is solved

[abscate]

Most of us have had to replace the electrical part of our ignition switch on high mileage P80s - I dove into my replacement from 2013 and this is what I found,comments on pictures

Executive summary - these switches can probably be put back into service by opening them up and cleaning the points inside the gray cover.

Part top view

Part Side view

Unstaking gray pot metal case, easy with small screwdriver or punch

View of cam and operating of points on terminals

Apart

Ready to pop off gray cover - note index

View of case, cam, points - note index mark and also ball/groove

Points view

Points view

Close up of points in Term 30, 10x macro - pitting evident

[erikv11]

These switches are often very loose when they are failing too, so the key rotates back and forth with little resistance. Can you tell or speculate what would cause that?

[matthew1]

Someone years ago said heavy keychains can cause problems with ignition. I have about 5 keys and my Volvo key, and no BS on mine, so I don't have any first-hand experience. But some people like to load up on the crap for their keys, and that weight swinging and pulling down for thousands of hours probably does it.

[matthew1]

Good post abscate. I'll put it in the VRD.

[abscate]

The 5th and 7th picture give you an idea on this erik.

IN the 5th, you can see there are white plastic eccentric cams - these open and close points which connect the various terminals based on switch position. There are two radii of points and two plastic cams that open/close them by the way.

In the 7th, you can see the ball bearing and groove that limits the rotation of the switch - Im guessing this wears out and the ball pops out, relieving tension and giving the 'loose spinning key' scenario

Worn cams will allow spinning, and perhaps are root cause of the points not fully closing, creating electrical chaos.

OF course, points can pit and grunge, like mine were, so Im guessing thats more likely how they fail.

Oh, important safety note. Some of the points are all normally closed, so don't put this back into car to test it without the cam in place - that could cause all sorts of havoc.

[cn90]

I did this cleaning for the "sake of science", ha...

- Problem: Sometimes cannot get out of Park ---> Drive, sometimes no headlight, sometimes turn signals do not work (but hazard light OK). Read the post by jblackburn and followed his advice, brand-new Volvo ignition switch ($55) solved all the problems!

- So I opened the switch as abscate showed above just for the heck of it. I do not plan to keep this switch simply b/c $55 every 10y/100K miles is not a bad thing. Plus it is a safety issue, I hate to have something going wrong with the "15" or "30" circuits causing stall etc. But I can see where abscate is coming from.

- I marked the 2 halves before separating them.

- Note the small amount of pitting where the contacts are. I made the mistake of pushing the copper tab out a tad too much, I could not bring it back properly for proper contact. So if you decide to clean the contacts with fine sandpaper, just slide the sandpaper down that tight space and slide it back and forth. Do NOT bend the copper tab like I did. This may work for people who are short on budget and are willing to take some risks refurbishing it. I have no desire to do that.

IgnSw-01.jpg (361.63 KiB) Viewed 4363 times

IgnSw-02.jpg (148.7 KiB) Viewed 4363 times

[abscate]

Nice. We can sell these to the Scots as almost new for a fiver, with a gallon of slightly used engine oil thrown in for free.

[scot850]

Where do I sign up for them....?

Neil.

[precopster]

Where do I sign up for them....?

Neil.

I was waiting for that.

[BEJinFbk]

For anyone into serious rehab of switch and relay contacts,
this is a handy little addition to your tool collection:

http://www.ebay.com/itm/GC-Electronics- ... 0420528397