Hazard Switch Repair

Post by **John in Simi Valley** » Sun Feb 15, 2009 3:22 am

Repairing the BMW E12 Hazard Switch

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_01.jpg">

Here's the emergency flasher from my 1980 528i. These seem to fail in every car, sooner or later. The button pops outward and when you push it back in, it doesn't stay. So now your flashers are on all the time. I had one give way at night, so when I went to start the car the next morning, my battery was drained. Pretty annoying!
 Here are some basic instructions on how to fix them when the go Ka-Put.

The general anatomy of this switch in this discussion is;
--->Button; the long forward body of the switch.
--->Bezel; slides over the forward portion of the buttom.
--->Rear Body; the rear contact area that houses the spring.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_02.jpg">

TOOLS REQUIRED will be 
--->Small slot (bladed) screw driver
--->Pliers, Needle-Nose
--->Diagonal Cutters (aka: dykes or wire cutters)


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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_03.jpg">

Using the screw driver, work it onto the seam and try to separate the front bezel (face portion) from the switch body. BE CAREFUL you can easily slip and STAB your hand if you're not accustomed to this operation; Leather gloves might be a good idea about now.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_04.jpg">

Once the blade of the screwdriver gets a little separation, slip it under the bezel skirt and lift the rectanular holes up and over the body snaps. Work your way around the lap joint CAREFULLY as to not damage the switch and your fingers.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_05.jpg">

In separating the fore and aft portions, be aware of an internal compression spring that applies opposing force. One end could "JUMP" off as the spring launches it.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_06.jpg">

In the body there is a claw pin that rides in a latch guide. This claw pin usually gets over stressed and over time, will bend slightly outward. We need to fix this by using the needle nose plyers and genltly bent it so the claw pin is a little more inward. This causes the pin to extend deeper in the guide for more positive engagement.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_07.jpg">

Here's a close-up of the claw pin as it has been tweaked inward. Note this doesn't need to be very much. Make the pin come inward about 1/32 to 1/16th if an inch (0.8 to 1.5 mm).

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_08.jpg">

Remove the compression spring and snip off the last coil on one end. Only do this on ONE END. What we are doing here is reducing the total spring force -- the same force that was overloading the claw pin in the first place. A very cool option is to take the spring down to a hardware store that carries a broad selection of little mechanism springs and try to select one that is the same size, but smaller wire diameter; lower spring rate = lower assembled force.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_09.jpg">

Remove the front bezel from the button. Make a mental note of how the button fits into the forward bezel.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_10.jpg">

Okay, HERE'S THE TRICKY PART. With the front bezel removed from the button. We need to assemble the button into the rear body and set the claw pin into the pin guide.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_11.jpg">

Work the buttom body into the rear body such that the claw pin rides up into the guide and back down so it catches. Got that? This is a two-handed operation, I'm using my other hand to operate the camera.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_12.jpg">

You must get to this point in the assembly where the pin is caught in the guide; the button and rear body are held together with the claw pin.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_13.jpg">

Slide the bezel over the button and snap the bezel together with the rear body. Keep track of the alignment tongue and groove.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_14.jpg">

Here's the switch after snapping it together.

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<img src="http://www.geocities.com/tunaoue/FirstF ... HER_15.jpg">

Test the mechanical operation of the switch; push to catch the "IN" position, then push to release to the "OUT" position. Cycle it a few times to make sure it's going to work. 
CONGRATULATIONS! Now go re-install it in your car.


A little off topic; 
Reliability is roughly 5 to 10 years; or about as long as regular household light bulb. This switch actually does a good job considering the signal and hazard lights all operate through it. But in this writer's opinion, it should be re-designed to last longer. Here's How: 
The spring force is the main issue. In NORMAL operation, with the button pushed in, the spring force is HIGH, it over loads the claw catch and the plastic guide. When the button is popped OUT, the blinking hazard mode is on -- Spring load is reduced, but only during the hazard-blink mode. One fix is to reverse the operation mode where the standard operation of the button is OUT (less spring load) and more fail-safe scenario. Press the button in to operate the hazard (like most cars today have). If they choose to keep the same design to prevent redesign and tooling/manufacturing costs, then change out the spring with another of the same size, but smaller diameter to impart a lower switch force.
 Hope the BMW engineers take note of this!

Bruce · Post by **Bruce** » Sun Feb 15, 2009 11:35 am

Excellent write-up! This should definitely be added to the Technical FAQ. I'm having the same issue with the Fog Light Switch and would think this applies. This is an example of how a technical FAQ should be written - clear, thorough but concise and well illustrated. Excellent job!!!

Post by **John in Simi Valley** » Sun Feb 15, 2009 1:40 pm

Thanks Bruce,
Checking part pricing, MSRP from the dealer is about $80 plus tax. A couple discount part retailers offer these for as low as $40 bucks.

With these instructions, I'm think most people should be capable of fixing the switch in 30 minutes. If taken to a BMW mechanic, the fix will be an hour of labor ($75 to 100), plus MSRP ($80) for somewhere around $150. Hopefully this will prevent an unnecessary wallet impact to someone in the future.

1st 5er · Post by **1st 5er** » Sun Feb 15, 2009 5:39 pm

Very very very nicely done.
Two thumbs up from this Lone Star State fan and definitely an archivable Tech FAQ.
Thanks for the detailed photos and language.

Pierre · Post by **Pierre** » Sun Feb 15, 2009 10:46 pm

What a coincidence.
I've been fixing hazard swiches using your method for years.
Thanks for the writeup John.

You know we have 5 members on this board in Ventura Country. (that I know of.)
Are you guys up for a get together? A cruise on PCH? Or a 33 Ojai run?

grumpsjr · Post by **grumpsjr** » Sun Feb 15, 2009 11:58 pm

Of course. I do feel bad that I can't figure out who #5 is: you, John, Warner, me,???

On Feb 15, 2009, at 19:46, "Pierre" <bimmerfan02@hotmail.com (bimmerfan02@hotmail.com)> wrote:

What a coincidence.
I've been fixing hazard swiches using your method for years.
Thanks for the writeup John.

You know we have 5 members on this board in Ventura Country. (that I know of.)
Are you guys up for a get together? A cruise on PCH? Or a 33 Ojai run?

Pierre in Camarillo
76 530i 3.3, 79 323i, 69 2002, 74 tii, 91 318is, 89 325i, 97 M3
OO==00==OO

Post generated using Mail2Forum (http://www.mail2forum.com)

Post by **John in Simi Valley** » Mon Feb 16, 2009 3:00 am

Let's see, Ventura County FirstFivers are:
Pierre, Thomas, Warner, Allyn, John and Bruce.
I guess that's 6 in V.C.

Then there are Chris, Paul who own E12s and the other Paul, the great Jeff F., Myron, Lindsay, Joe and Bruce Barthel who live locally in Ventura and SFV who used to own E12s, but are still E12 & BMW fans. (Well, Paul Purmort still owns a Dinanized '79 528i, but it doesn't run at the moment.) this second group will on occasion check firstfives. Oh, can't forget about Michael and Grip Greg from Long Beach.

Warner suggested having a local group E12 run, something casual. i suggested lake hughes road above castaic lake and maybe Soledad canyon or little tujunga cyn road returning. That may be a little out of the way for some.

My fear of highway 33 this time of year is the potential ICE on the road at the top of the mountain. Fording that river may be a challenge with all the rain we're having.

There are a ton of drive options to choose on a weekend morning. The big question is how much time do we have for this? 2 hours? 5 hours? All day? I'll play it by ear for now.

By the way, how did it go at Willow Springs racing around with all the other BMWs in the rain?

Pierre · Post by **Pierre** » Mon Feb 16, 2009 10:48 am

The SoCal BMW Vintage group had a drive yesterday (Sunday) on PCH/mulholland. 11 cars showed up. It was more of a cruise than a drive but the weather was glorious, the roads were a little crowded and the company was great fun.
I am planning a tax run around April 15th (HWY 33) but we could do something more mellow with the E12s before that.
We could met at 7:00 AM somewhere, cruise for a couple of hours athen stop for breakfast somewhere and be home before noon. Or we could skip breakfast and be home by 10:30 AM.
Any suggestions for a local road?

O Johnny · Post by **O Johnny** » Mon Oct 26, 2009 2:55 pm

Hello John in Simi Valley,
Newbie to the e12 and firstfives.org. For some reason not able to see the images with your tutorial of Feb 15th 2009. Might you be able to re-post or send to my email address johnkmorri@aol.com? Thanks so very much.
O Johnny

1st 5er · Post by **1st 5er** » Mon Oct 26, 2009 9:51 pm

Yep, pics ain't workin'.

trasmu82 · Post by **trasmu82** » Tue Oct 27, 2009 10:52 am

They were hosted on geocities...

geocities was discontinued on Oct 26th 2009

O Johnny · Post by **O Johnny** » Tue Oct 27, 2009 3:37 pm

Wow, Geocities went belly up... I had thought they were a leader in that space.

EURO M3 CSL · Post by **EURO M3 CSL** » Thu Oct 29, 2009 10:32 am

maybe change the pictures to photobucket? yea mine is stuck out as well

using a small pin to hold it in now

Firstfives.org