Both sides brake and reverse lights out

Post by **mgjh** » 21 May 2010, 05:51

I have an 88 240 wagon. Recently replaced passenger side rear light unit & bulbs with cheap (won't do that again) aftermarket unit. Since then, both upper brake lights and reverse lights are out & there is no power into the driver's side upper two bulbs. From what I've been reading, it sounds most likely to be reverse light switch, brake light switch or bulb failure relay, however I'm pretty ignorant as far as electrical goes. My questions are:

1. What are the easiest ways to access brake and reverse light switches (manual transmission)?

2. I have a multimeter but am not sure how to use it to test current at switches or bulb failure relay. Help?

3. Given that both sides are out, does that help identify exactly what component has malfunctioned?

4. Could it be something other than these switches or relay?

Also, not sure if it matters, but it also looks like I have a temperamental ignition switch. Thanks in advance for any help/suggestions!

cmblackburn · Post by **cmblackburn** » 21 May 2010, 08:06

First off, you should try checking fuses. I'm pretty sure in all cars there's a fuse that controls those lights, and the cheapo bulb you put in may have drawn too much current and blown a fuse.
Do your turn signal lights work? I wonder if you messed up a connector somewhere along the line.

Post by **mgjh** » 21 May 2010, 13:34

Thanks for the reply. Checked fuses and doesn't look like anything's out. Both turn signals work and running lights are good, but I'm pretty sure those are on a separate circuit.

Post by **mgjh** » 29 May 2010, 15:52

I'm getting a crash course in basic circuits, but still can't figure out what's going on. Here's what I've eliminated:

Fuses good
Brake switch is good (tested for 12v)
Bulb failure sensor is good (tested blue/red in, yellow/white & yellow out for 12v)
All plugs and bulbs are good (tested for continuity)
Both (R & L) reverse lights and upper brake lights went out at same time but lower brake lights and turn signals working fine

I'm not sure where to go from here- thoughts? Thanks in advance.

Post by **billofdurham** » 30 May 2010, 03:48

There is a common fault on these due to bad design. The wiring to the rear lights comes along the roof and down the hinge of the tailgate. Over the years the wiring starts to deteriorate at the hinge. Do a search using "tailgate wiring" for more information. Our sponsor IPD sells the harness to make the job easier.

Bill.

Post by **mgjh** » 30 May 2010, 07:29

That makes sense- I looked up tailgate wiring as suggested & symptoms described sound similar. The third brake light is also out & rear wiper is getting power but not working well. But why are the top two lights (reverse & brake) in both taillight units out? I'm trying to understand how the wiring is routed. Does the circuit go from bottom two lights (brake and turn) through tailgate, then to upper two lights? Is there a test I can run to really isolate cause? From what I read, it can be a little challenging to rewire the tailgate on your own- I'd like to just make sure I've identified exactly what's going on before I take things apart. Thanks.

Post by **billofdurham** » 30 May 2010, 12:24

I'm going away for 10 days from tomorrow. How I wish I had gone today.

Only joking.

The top two lights on the 240 estate (wagon) could be rear fog lights not brake lights. Apparently in the US market certain models were fitted with brake lights and others with rear fogs at those locations. UK models had rear fogs.

Looking at the wiring diagram for the US model with brake lights at the top position they are linked to the brake light lower down. As there is no wire running to these lights through the tailgate it can't be broken. This then begs the question do you have a car fitted with rear fog lights or brake lights at the top position? If you have fog lights there will be a white wire going to the connector at the top position. Usually the lead in for the fog lights is to the left hand light first so there should be two whites there, one in and one out going to the right hand side. That is the set-up on my wiring diagram but it has been known for them to be the other way round. You will also have a rear fog light switch on the dash. If you have brake lights at the top position there will be no wires going to those bulbs.

The reverse lights, according to my wiring diagram, are wired to the driver's side first with a black wire in and a black wire out to the other reverse light, but again, that could be reversed. To do a quick, and safe, check on the reverse lights run a wire from the battery positive terminal and back probe it into the plug for the reverse lights. This should be done at the side with the two wires and it should illuminate both bulbs. Another way of checking is to engage reverse with the ignition on and test for 12 volts at the bulb holders with your multimeter. No 12 volts would indicate a blown fuse, a broken wire or a bad connection at the reverse light switch

Bill.

Post by **mgjh** » 14 Aug 2010, 07:10

It actually ended up being the fuses. I had put new ones in, but didn't clean the contacts in the box. After carefully toothbrushing those w/a baking soda paste, I replaced all fuses and voila! I have light! Thanks.

SmokinJazz · Post by **SmokinJazz** » 17 Jun 2015, 20:22

I just went through a situation with having no reverse lights, but I had swapped out the tail light assemblies for less expensive aftermarket ones. I actually did this a few months back with no issues and then got rear-ended (the other car ended up with a ripped up front passenger quarter panel and my trim got knocked off and tail light broke, but no other body damage at all).

So I re-ordered another after market light, but this one had a little kink in the the tab where connection hooks on. I couldn't flatten it out enough, I simply swapped the filament sheets and everything worked just fine. I hadn't seen any posts talking about the filaments being a possible issue, so I wanted to post this out there to hopefully help others!