I am currently driving a 940 wagon, 1993 and have unsuccessfully attempted to wire for a trailer. I purchased the recommended converter (now no longer available) installed per instructions and have only working directionals, no tail lights or brake lights. To further complicate things the "bulb out indicator" is now on when I 1) apply the brakes or 2) turn on the head lights. When I step on the brake pedal the left tail light, where I wired the brake wire to, goes out.

The recommended wiring goes like this: the converter has five wires, three are wired to the car, and two are wired to the trailer connector. the three for the car are marked: left directional, right directional, and brakes, all of which I wired in with crimp-down connectors. the two for the trailer are marked: left turn and right turn, both of which I connected to the two turn wires on the four prong flat trailer connector, this still left the white neutral unwired and the brown taillamp unwired.

Can anyone help???????

I'm not intimately familiar with the U-Haul converter, but the trailer wiring story goes something like this.

A proper 4 lamp to 2 lamp Euro->US converter must have (at a mininum) wires that connect to the vehicle brake, left and right turn lamps plus a chassis ground. Most, but not all, will have a wire for the park lights. Some (the best kind) will have a +12v power line.

There are two basic kinds of Euro-US trailer light converters. If wired correctly, these units should not interfere with the vehicle bulb out sensor. Depending on quality and accidental misuse, both are subject to failure.

One is a small sealed unit that usually sells for under $20. You'll see these in places like WalMart. It gets power to run itself and the trailer lights from the vehicle light circuits. The unit consists of protective diodes, switching transistors and pull down resistors. There is a noticeable voltage drop through these units, as low as 5 volts DC out if really cheap transistors are used. The result is that the trailer lights, particularly the brake/turn lights will be very dim. They also tend to dim with age as the components inside start to fail. Add a slightly corroded socket and a bad ground connection between the trailer and vehicle and you'll have a stealth trailer -no visible lights. These units also tend to fry at the first sign of a short or overload. They are also capable of upsetting the bulb out sensor if cheap, unmatched components are used inside.

The next level up are the direct powered systems which cures the dim light problem and also allows more trailer lighting without blowing the vehicle lighting fuses. As the trailer lighting is separated there is even less of a chance of upsetting the bulb out sensor. These units consist of relays using the vehicle lighting circuits to control the relays which then feed battery power to the appropriate lights. Prices range from $25 to over $150 depending on the number, size and quality of the relays, the number of circuits supported and the amount of wiring and connectors supplied. Apart from the OEM variety, you can also get these through auto parts suppliers although they may or may not be an in-stock item.

When you order an OEM trailer wiring kit or towing package from a dealer you're normally getting a proper relay driven system. On SUV's you'll often find these boxes mounted under the hood or under the dash with a standard connector plug at the rear of the vehicle.

For installing a trailer wiring converter on your Volvo with a bulb out sensor, there are three things to know:

o Get the brake light source from a point before the bulb out sensor (like directly off the brake pedal switch -sometimes the 3rd brake light wire can also be used).

o Get the park/running light source from a point not on the bulb out sensor (like the license plate lights and sometimes the side marker lights).

o Make a solid ground connection to chassis bare metal. Protect from corrosion with something like OxGuard. Never rely on the hitch or chain as a ground circuit to the vehicle. Make the trailer ground connection at the lamp sockets rather than using the trailer chassis. When troubleshooting trailer light problems, 70% of the time it will be related to a bad ground connection.

If you're competent enough to follow all these wacky fixs and work arounds (Take out the bulb-out indicator bulb and tape it? Are you serious?), then I'd say you should have been able to start with a Volvo harness and wire it yourself. I had one installed because I have neither the knowledge nor the time to learn how to do this wiring. But the system works flawlessly and the connector to the trailer fits very professionally under the rear bumper just to the left of the hitch. I also bought the Volvo converter which works well with U-haul trailers.

Sorry, I know that cost is always an issue, but I would either put up with he indicator light being on during trailering or do it right.

John -

I am a 240 guy, but if the buld failure system is the same, and it sounds like it, here is what I have planned for when I face the same problem:

Tap the brake lights from the high-level light, it doesn't go thru the sensor. Tap the tail lights from there at the light switch before it goes to the BF sensor relay. Turn signal ought to be OK to tap into right in the trunk.

Good Luck,

Bob

:>)

It doesn't seem that you got the right hookup, which should be the one with the logic box that turns the signal from the amber turn indicators into a signal for the dual-purpose red lights of the trailer.

Like Leon said, U-haul has those for cheap. They work really well, actually, but you MUST get the one that has the seperate connectors, or it will never work at all.

The bulb out indicator (in my experiences) is one sacrifice you make when you tow a trailer. The sensor is skewed because of the additional resistance in the circuit.

I had good luck purchasing a hook up from U-Haul and they installed it for $19.95. It works great but with the trailer lights hooked up the "bulb out indicator" stays on.

The only to get everything to work without the bulb out indicator coming on is to wire it before the relay. That means running wires to the dashboard. Get the U-Haul converter. They work. And remove the bulb for the indicator or put a piece of tape over it. When wiring the converter, L turn, R turn and brake lights wire to the converter. You still need a seperate wire from the taillight circuit to the trailer. The trailer harness should have 4 wires. L turn, R turn, taillights, and ground.