Volvo Electric Cooling Fan Conversions

CONVERSION #1 -- GM 14 and 16 inch Fans

Excuse the photo quality. This is a very old pic. This is the first electric fan conversion I did back in 1997 for my 245 Turbo. I also used this fan for several conversions of friend's 240s and one I know of is still going strong and cooling flawlessly more than 10 years later.

The fan depicted is at left from an early to mid-eighties Buick Century, Pontiac Grand Am, Olds Cutlass, or other General Motors mid-sized car with FWD and 4 or 6 cylinder. It is made by AC Delco and is designed to be the primary fan for the car it originated in. This fan will likely be plentiful in any self-service auto salvage yard and should cost between $20 and $30. Dimensions for this fan are as follows:
Height and Width: 17 inches at shroud edges
Depth at shroud housing next to motor: 3 1/8 inches
Depth at rear of fan motor: approx. 4 1/4 inches
Fan blade diameter: 14 inches.

A 16 inch diameter fan in the same typical version can also be found in som GM 6 cylinder cars. The outer dimensions will be the same. This is important because this shroud is the pefect size to fit directly onto the typical Volvo 240/740 radiator.

All four of the original plastic mounting ears on the shroud need to be removed for fitment to a Volvo radiator.
A hacksaw does just fine here. In this photo the ears have already been cut off, but I left them next to the fan so you could see where they came from.

Since this fan will be mounted to the radiator, you'll need some mounting hardware. The simplest method will be with some 2 inch sheet metal screws, washers and these funny little sheet metal nuts. The screws I used were the counter-sunk type with some counter-sunk finishing washers. Most any will work though.

This photo shows an existing hole in the top flange of the radiator. All Volvo radiators will have these holes for mounting of the original fan shroud. The sheet metal nut can be used here. You will then need to drill a small hole in the GM fan shroud directly over the original hole in the radiator.

The plan is for the new fan shroud to be fastened to the radiator by four such sheet metal screws, two at the top and two at the bottom. You may need to drill the holes in the bottom flange if there aren't already suitable holes.

Here we have the new fan mounted to the radiator.
This can now be placed in the car as one unit and mounted as any Volvo radiator is mounted.

To make this fan work in your car, you have several options. You can purchase an all-in-one fan controller with a temperature probe that goes into the radiator fins. You can use a sensor mounted in your radiator if it has one. For an assortment of wiring diagram options, click here (pdf file).

2009 Conversion for my 242: This is a very popular fan used in many conversions. It's found in 1992 and later Volvo 940 and 960 models as well as all 850s. There is a similar fan found in the S70 and S80, however the S80 models I have seen feature a smaller, more compact motor. I'm not sure if it's capacity is less. All of these fans are two-speed models, with low speed being about 50% of high speed. The motor will have three wires; one ground and two hot wires (one for low and one for high). A two speed circuit may be used when you install one of these or you may use just the high circuit only. My installation used the the high speed only.
For an assortment of wiring diagram options, including two-speed circuits, click here (pdf file).

This fan is about 4 inches deep from the motor to the furthest point on the fan. The fan shown in the far left has been removed from the fan shroud. After being removed from the original shroud, you'll find that it is about 17.5 inches across at the outer ring, which is why is fits so well into the Volvo RWD mechanical fan shrouds, which have 18 inch openings . The actual fan blade portion on this fan is only 15 inches.

One cool thing about this fan is it simply unbolts from the original shroud. No cutting or shopping needed. The 940 shroud is too wide for a 240 or 740 radiator, so it should be tossed out for this conversion, although some people have cut them down to fit. The shroud used in the photos here is a 240 Turbo (Intercooled) shroud. The inside diameter of this shroud is 18 inches. This particular shroud will only correctly fit the 240 Turbo. It will not clear the auto transmission cooling lines in a 240 non-turbo or a 740. Since this shroud sits further back in a Turbo Intercooled car (because of the intercooler), some extra work was required to get the fan to sit deep enough into the shroud to clear the water pump. It was a tight fit when done.

The shroud from a 740 Turbo (which can be seen in the Ford fan conversion below) is a much better choice to mount one of these fans into. The 740T shroud, also with an 18 inch opening, may be used in any 740 or 240 model without any fitment issues. And this shroud places the fan closer to the radiator, offering at least 1 inch more clearance from the water pump than a 240 Turbo shroud does. Plus it's a lot less work making it fit in a 240.

The above fan pulls a lot of amps upon start up when using the high speed circuit only. Because I wanted to avoid sudden, hard current draws in my charging system when this fan came on, I sought out a high-tech fan controller that offered a "soft-start" feature for the fan motor. I chose the Delta Current Control FK-50P. This is an all-in-one controller and it works smoothly, so no relays or other sensors are needed. When it's time for the fan to come on, it comes on slowly and smoothly, beginning with about 10% speed until more speed is needed to control temperatures. It regulates your radiator temperature by smoothly increasing or reducing fan speed, instead of on, off, on, off, like the old school method. While not cheap, it is a very nice device. http://www.dccontrol.com

CONVERSION #3 -- Ford Thunderbird SC 17 inch Fan

May 2010 conversion for my 242: This fan is only found in the T-Bird SC (with supercharged 6 cylinder) made in the late 1980's to mid-1990's. The circular portion on the shroud is 17.5 inches across, so after some chopping, as seen in these photos, it fits very well into the 18 inch opening of the Volvo 740 Turbo fan shroud. I sought out this fan because after using a heavy duty tropical fan clutch for many years in my 242 Turbo, I was spoiled by how great it cooled. I tried the 940 fan above for a while. I was disappointed. It did not cool as quickly or as efficiently as I liked. I believe this disapointment was because the 15 inch fan was sort of a bottleneck and the volume of flow through the radiator was reduced compared to the heavy duty mechanical clutch fan. It was easy to see a difference on uphill grades, especially with the A/C on.

Here is the Ford fan next to the 740 Turbo shroud I used to mount it in.

The Ford shroud needed to be cut down, separating the fan and circular ring that was then mounted into the Volvo shroud. I used a friction cutting wheel to trim the Ford shroud, which worked ok... not the best job. A sawzall with a fine blade would have worked much better on this plastic.

Here is the in-progress assembly and completed fan. The last pic shows it mounted in my 242 Turbo. The depth of this unit from the fan motor to the front of the fan is only 3.75 inches (a little shallower than the 940 fan). This is a two-speed fan, like the 940 fan, except this one is much, much more powerful. The low speed on this fan probably pulls at least as much air as the high speed on a 940 fan. I have read that the high speed on this fan pulls between 35 and 40 amps when running continuously. So this is NOT a fan for a light-weight charging system. A large capacity alternator (100 amp), heavy cables to the fan motor and a high capacity relay (50 to 70 amp) would be a good recommendation. For an assortment of wiring diagram options, including two-speed circuits, click here (pdf file). For my installation, I used the Delta Current Control unit shown above, controlling the fan high-speed circuit.