Reverse lights not working

[lagunae34m5]

I just realized the other night that my reverse lights are not working. No message about bulbs being burned out, so my assumption is the reverse gear sensor at the transmission.

Is that a common issue with our cars?

How hard is it to replace? I might as well swap the tranny fluid at the same time...

cheers,

[joosyjoos]

Bump. I have the same issue with my '95 M3.

[EricP]

Insanely easy.. and cheap. It's probably the reverse light switch on the side of the tranny, has a little wiring harness running out of it. You can't miss it. It just unscrews.

[ECSTuning]

Good chance it's the reverse light switch. HERE (http://www.unitedbimmer.com/kb-e36-reverse-lights-switch.php) is a link to a pretty good diy on the switch. Also I have the switch for the E36 available HERE (http://www.ecstuning.com/ES42636/?salesrep=JRiggsbee&utm_source=bimmerforums&utm_medium=forum&utm_content=JRiggsbee&utm_campaign=postreply). Below is a photo of the switch for reference when you're digging around looking for it.

http://c1552172.r72.cf0.rackcdn.com/32117_x600.jpg (http://www.ecstuning.com/ES42636/?salesrep=JRiggsbee&utm_source=bimmerforums&utm_medium=forum&utm_content=JRiggsbee&utm_campaign=postreply)

ECS

[jayjaya29]

Hrm, never woulda guessed that such a switch could fail. Guess I'll replace mine too.

EDIT: Just fixed the problem, was actually the reverse light bulb sockets not the reverse switch. I simply bent the contacts in the sockets outward a little and presto working reverse lights!

[dwonda]

Hrm, never woulda guessed that such a switch could fail. Guess I'll replace mine too.

EDIT: Just fixed the problem, was actually the reverse light bulb sockets not the reverse switch. I simply bent the contacts in the sockets outward a little and presto working reverse lights!

Yup back to 2012 we go...

So your reverse lights weren't working because somehow spontaneously, both bulb sockets decided to come loose?

[Wheelyneat]

I had the same problem on my '96 coupe and the fix was the same. One bulb was not making good contact with the contacts in the socket. Carefully bend the tabs out, clean everything up and apply a light smear of dialectric grease to the base of each bulb before reinstalling them.

[shogun]

That is always the first thing to do when there is a problem with lights on the rear, checking bulbs and the sockets and re-bending the tabs, and the idea with dielectric grease is good. It is designed to seal out moisture and prevent corrosion on electrical connectors.

[dwonda]

That is always the first thing to do when there is a problem with lights on the rear, checking bulbs and the sockets and re-bending the tabs, and the idea with dielectric grease is good. It is designed to seal out moisture and prevent corrosion on electrical connectors.

Sure sure, yes I'm quite familiar with this process. But just to be clear, it is belong suggested, that this happened to both lights at exactly the same time?

[jayjaya29]

Yep.

Funny thing is that my reverse lights (both of them) aren't working again. I'm gonna mess with the bulb contacts again before throwing in a new switch.

[dwonda]

Yep.

Funny thing is that my reverse lights (both of them) aren't working again. I'm gonna mess with the bulb contacts again before throwing in a new switch.

Ok so this is interesting... It would probably help if I better understood the electrical diagram but this is what happened... With my car off, and my key on, and shifter in reverse. I went to the back, no reverse lights on. I started with the driver side first, accidentally took out the wrong bulb socket, and instead a brake light bulb. This is when I noticed the passenger side reverse light came on. Then I took out the driver side reverse light bulb socket, played with it a bit, put it back in and now both reverse lights are working. AFTER I ordered a new switch *palmface*. So somehow lights on the left can affect bulbs on the right. And it really surprises me that there is no message for reverse light failure. I suppose BMW decided they weren't that important.

[jayjaya29]

Weird. Hopefully they continue to work.

[dwonda]

Weird. Hopefully they continue to work.

Turns out it had nothing to do with the bulbs or sockets, and everything to do with the wiring harness plugging into the driver side tail light. When this is unplugged for example even the lights on the passenger side go out, and I guess the pin for the reverse lights wasn't making good contact, so I cleaned things up a bit and plugged it back in, all good now.

[shogun]

Good to hear, thanks for the info. And that makes sense, see here cable harness sector routing rear http://2009.bmwfans.info/parts/catalog/E36/Sedan/USA/M3_3.2-S52/LHD/A/1998/february/browse/vehicle_electrical_system/cable_harness_sector_rear/

[MMMGP]

Funny... On my manual, the switch on the side of the transmission was faulty at 70k miles. And on my automatic the bulb sockets were loose.

[pizzaman09]

I have a bit of a different problem with my reverse lights. I looked under the car to see if the sensor was plugged in and what I found was two bare un-terminated wires near the reverse light switch.
Does anybody know what the part number is for the plug that goes into the reverse light switch on a manual 328is?

I just purchased the car a few days ago and have no less then 5 lights that are not working, quite impressive for a car that was registered and inspected. I also need to purchase the holders for the reverse light bulbs as they are missing.

[jayjaya29]

I have a bit of a different problem with my reverse lights. I looked under the car to see if the sensor was plugged in and what I found was two bare un-terminated wires near the reverse light switch.
Does anybody know what the part number is for the plug that goes into the reverse light switch on a manual 328is?

I just purchased the car a few days ago and have no less then 5 lights that are not working, quite impressive for a car that was registered and inspected. I also need to purchase the holders for the reverse light bulbs as they are missing.

Probably best off going to a junkyard to get all the pieces you need.

[Eyecon82]

Both of mine spontaneously blew out

[02fanatic]

This is a great thread! Don't we just love E30's? I have had an issue for a couple of years with the reverse lights not working! I promised my Indy BMW mechanic that I'd get them working before the annual inspection so finally today I replaced the backup switch on my 1990 M3 & guess what? No workie! I tried bending the tabs under the bulbs, both bulbs look brand new & I checked the wiring under the shift boot. I did not troubleshoot with a multimeter though. They used to work but nothing now! Fuse is fine & btw can you believe the E30 Owners manual doesn't have fuse information? Fortunately I have an original blue workshop manual. So, I'm stumped! Could it be the wiring harness connector at the taillight assembly? Everything else works fine.

Any ideas?

Thanks!

[RRSperry]

wrong section... this is E36 not 30... But thanks for playing...

[02fanatic]

Thanks....my apologies. At least it's a similar problem. I'm beginning to believe it's the backup switch not having a long enough plunger to be depressed far enough by the reverse shift linkage in the trans. I found a lot of help on the s14 forum. Possibly this is a somewhat universal problem.