240 Just bought - reverse lights and rot to sort?

Hi! I just bought my first car and of course it's a beautiful blue 5 speed '90 240 (245), so I figured I'd finally join this forum.

There's a few problems though and I thought who better to ask than you guys? Well first the reverse lights don't work. I took apart the taillights to poke around and I'm really not sure what to look for. The bulbs are fine though, so I'd have to guess that it's a problem in the harness somewhere but I'm really not sure what to look for. I bought a multimeter to look for where the problem might be exactly but I was hoping for some tips on how to use that, too, in this sense. Like should I have the car on in reverse? But then someone would have to step on the clutch the whole time.

The only other urgent seeming problem is the rust in the spare wheel well. It actually goes through to the ground, and I didn't notice before I bought it. I saw this guide while looking for a way to fix it and I was wondering if there was anything wrong with the technique used.

All in all though, I love it so much. It's been such a blast to drive and learn manual and it's been the best time to drive. It's got no radio, so for now I get to listen to the lovely engine while I drive. I don't regret it for a second!

I'll have a picture of the spare well rust hopefully by tomorrow, but here's a picture of the ride itself.


Rust:

That guide seems like a legit (if not pretty) way to repair your rusted out spare well. I would recommend that you saw out the rust before ordering the patch as there may be more there under the paint than you first realize. There may be a TB member local who will weld in your patch for a reasonable price - welding is always better than pop rivets if you can get it economically. Finally, drill some drain holes in the bottom of the patch and give it a good thick coat of paint (preferably rust inhib. paint) to prevent this from happening again.

Check under the plastic trim at the door sills, IIRC that's another super common rust area.

Oh, and welcome aboard.

As far as the reverse lights go - Check the fuse first to make sure it's not blown. Then, make sure the bulb is firmly seated in the holder and has good contact (bend the tabs on the holder a little if necessary) Then, with it in reverse, check for power at the bulb (multimeter in DC Volts mode between the "hot" wire and a ground) and at the fuse (ditto).

If there's no power at the fuse I think the most likely culprit is the switch that detects you shifting into reverse. If there's no power @ the bulb but power at the fuse then your wiring is suspect.

The wiring goes though the rear door hinge: a known problem / failure area.

I don't think the wiring for the reverse lights goes through the tailgate. Understandably it would for the license light, wiper and defrost grid.

As for using a multimeter, they're pretty simple. There's likely a dial on it which you would set to V DC (volts, direct current). There may be a few options under that setting. You should set it to the closest that's over 15 volts. Though your car is a 12 volt system, the alternator output is a little more than 14 volts.

To test the bulb socket, you don't have to have it running with someone holding the clutch down. Simply put the car in reverse and turn the key to KP II (key position 2) without starting the car. This will power up the circuit. You may even be able to use KP I (key position 1), but I'm not sure on a 240. I try to not leave the key in the "on" position (KP II) without the engine running for more than a few minutes.

Hold the black probe on the multimeter against something that is unpainted metal on the car and use the red probe to touch the center of the bulb socket. You should get somewhere around 12+ volts displayed on the multimeter.

Check the fuse first though.

You can use the multimeter to check the bulb too by setting the dial to Ohms and placing the black probe on the metal side of the bulb and the red probe on the bottom. The readout should be "0" as in zero resistance.

when I got my 240 Manual, the reverse lights did not work. I had a harness hanging from the bottom center of the car by the shifter area, and it needed to get plugged in on top of the transmission. Literally had 2 prongs on top of the transmission, high up above the crossmember. Had to hug the tranny to find them and re connect.

^ Not much help, but atleast a general direction if the above tips from alschnertz don't check out

Yeah you probably have rotten wires above the tranny. I do! Kept blowing the fuse until I unplugged the wiring connector for em inside the cabin. I need to fix it, but haven't done it yet. Passing smog is at the top of the list.

Unless you have your reverse wires in your tailgate, wink, it has absolutely nothing to do with tailgate wiring.


We don't wanna see rust pics! Just take pics AROUND the rust and show us her good side if anything.

You guys...


The reverse lights in an automatic 240 are triggered by the PNP switch. To access the switch, carefully remove the gear selector knob and the gear selector trim/surround. Once that's free, you'll see the PNP switch in the metal "bucket". It's held in by two philips head screws. Remove the screws and wiggle the switch out. Once it's out, you can move the white plastic lever to see what pins are jumpered when.

Those switches like to get crusty and grungy down in there. A simple cleaning may get your lights operational again.

There's only one wire that actually goes to the transmission itself in an automatic 240, and that's the signal wire for the overdrive solenoid.

propav8r said:

You guys...


The reverse lights in an automatic 240 are triggered by the PNP switch. To access the switch, carefully remove the gear selector knob and the gear selector trim/surround. Once that's free, you'll see the PNP switch in the metal "bucket". It's held in by two philips head screws. Remove the screws and wiggle the switch out. Once it's out, you can move the white plastic lever to see what pins are jumpered when.

Those switches like to get crusty and grungy down in there. A simple cleaning may get your lights operational again.

Click to expand...

You guy.... ready the first sentence in post one. Or second sentence paragraph 4.... Quoted so no ninja edit! ha. j/k.

ZVOLV said:

You guy.... ready the first sentence in post one. Or first sentence paragraph 4.... Quoted so no ninja edit! ha. j/k.

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Aw...where did I get automatic? Sigh.

Reverse lights in an auto, ya, should be rock solid reliability with the switch inside the cabin. My poor exposed manual tranny wires have taken a beating with all the oil and heat down there over the years. Just like OD wires do on the auto tranny.

Khrrck said:

That guide seems like a legit (if not pretty) way to repair your rusted out spare well. I would recommend that you saw out the rust before ordering the patch as there may be more there under the paint than you first realize. There may be a TB member local who will weld in your patch for a reasonable price - welding is always better than pop rivets if you can get it economically. Finally, drill some drain holes in the bottom of the patch and give it a good thick coat of paint (preferably rust inhib. paint) to prevent this from happening again.

Click to expand...

Okay. I'll probably do that as soon as possible. My main concern is the wheel in there making it bigger. Thanks for the advice!

Khrrck said:

Check under the plastic trim at the door sills, IIRC that's another super common rust area.

Click to expand...

Will do! You mean all round the car or are the back or front particularly problem areas?

Khrrck said:

As far as the reverse lights go - Check the fuse first to make sure it's not blown. Then, make sure the bulb is firmly seated in the holder and has good contact (bend the tabs on the holder a little if necessary) Then, with it in reverse, check for power at the bulb (multimeter in DC Volts mode between the "hot" wire and a ground) and at the fuse (ditto).

If there's no power at the fuse I think the most likely culprit is the switch that detects you shifting into reverse. If there's no power @ the bulb but power at the fuse then your wiring is suspect.

Click to expand...

I'll go do this now. Do I do red prong on the fuse and black to ground to check the fuse?

Khrrck said:

Oh, and welcome aboard.

Click to expand...

Thank you

alschnertz said:

To test the bulb socket, you don't have to have it running with someone holding the clutch down. Simply put the car in reverse and turn the key to KP II (key position 2) without starting the car. This will power up the circuit. You may even be able to use KP I (key position 1), but I'm not sure on a 240. I try to not leave the key in the "on" position (KP II) without the engine running for more than a few minutes.

Hold the black probe on the multimeter against something that is unpainted metal on the car and use the red probe to touch the center of the bulb socket. You should get somewhere around 12+ volts displayed on the multimeter.

Check the fuse first though.

You can use the multimeter to check the bulb too by setting the dial to Ohms and placing the black probe on the metal side of the bulb and the red probe on the bottom. The readout should be "0" as in zero resistance.

Click to expand...

Alright, I'm going to go check that now and report back as soon as possible.

nudextro said:

when I got my 240 Manual, the reverse lights did not work. I had a harness hanging from the bottom center of the car by the shifter area, and it needed to get plugged in on top of the transmission. Literally had 2 prongs on top of the transmission, high up above the crossmember. Had to hug the tranny to find them and re connect.

^ Not much help, but atleast a general direction if the above tips from alschnertz don't check out

Click to expand...

Thanks! I'll peep if it turns out that nothing else works. And this is located just underneath the car?

Okay, so I went out to go check all the stuff with the multimeter. And it looks like with the lights fully off so that the license plate light and the dash light wouldn't interfere, and the car in R, the fuses for L and R "parking lamp" (which is the only one that makes sense to be reverse lights... Right?) had zero voltage. I was afraid I was doing it wrong, so I turned on the lights to double check with the license plate and dash lights on and I got a voltage.

I also checked the taillight. First as a base, I checked the rear fog light and I got a voltage of about 10. I checked the resistance of the reverse light's bulb and got 0 so I think that's good, right? But when I checked the voltage I got 0 too.

ZVOLV said:

Yeah you probably have rotten wires above the tranny. I do! Kept blowing the fuse until I unplugged the wiring connector for em inside the cabin. I need to fix it, but haven't done it yet. Passing smog is at the top of the list.

Click to expand...

So it's looking like Nudextro and ZVOLV's idea that it might be the wiring underneath the car is going to be the case. Which sucks, but at least I identified the problem, I think. Someone tell me if I did something wrong. So how would I fix that? I have to pass inspection in a few days haha.

Also, I put another picture of the bus and a picture of the well rust in the OP.

http://www.volvowiringdiagrams.com/volvo/240 Wiring Diagrams/Volvo 240 1990.pdf

So I looked at the wiring diagram (link above) - and it looks like the reverse light switch is on the other side of the fuse than I thought, so testing at the fuse block probably won't tell you anything. You'll want to check the switch itself. It's #11 on this diagram.



Unfortunately that means it's on top of the transmission... If you can get at it, check for resistance across the switch. Should be 0 with the transmisison in Reverse. Car doesn't need to be (and shouldn't) be on.

Ahtum said:

Okay. I'll probably do that as soon as possible. My main concern is the wheel in there making it bigger. Thanks for the advice!

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Put a plank in the bottom for now, or just put the wheel in the cargo compartment (tie it down so it doesn't bean you in a collision)

I suggest you get a Bentley, it'll really help you.

http://www.amazon.com/Volvo-240-Service-Manual-1983/dp/0837616263

Khrrck said:

Unfortunately that means it's on top of the transmission... If you can get at it, check for resistance across the switch. Should be 0 with the transmisison in Reverse. Car doesn't need to be (and shouldn't) be on.

Click to expand...

Ouch... How do I access the tranny? Do I go underneath or do I go through the shifter? That seems rough.

Khrrck said:

Put a plank in the bottom for now, or just put the wheel in the cargo compartment (tie it down so it doesn't bean you in a collision)

Click to expand...

That's a solid idea. I'll probably do that till I fix it, thank you.

Ahtum said:

Ouch... How do I access the tranny? Do I go underneath or do I go through the shifter? That seems rough.

Click to expand...

Ask someone else, I have an automatic. I suspect you'll have to get at the switch from underneath if it's possible at all. Use jack stands and be safe when lifting the car.

You put the car in the air, disconnect the plug from the sensor, and then dig out the wiring harness from inside the cabin. You then cut out the old rotten section and splice in a new pair of fresh wires. Go for it!

You could try it from underneath, but good luck getting your hands up above a greasy tranny and doing wire splicing.

google searchage. see the sensor on the top!?

The wires on my car just kept coming unplugged there so I no longer have working reverse lights. They do work when properly plugged in.