In the middle of installing a tachometer in my '80 245, and can't figure out how to wire this thing. I was going to just run a wire to the coil, but I don't know how to get a wire there. Someone said eariler I could just run a wire to the fuel pump relay, but I have no idea where it is, or what it looks like.

When I do find the relay, where should I run the wire to?

Thanks for any and all help.

You might look on the driver's side at the firewall inside. That's where the fuel pump relay is on my 82 245.

That's exactly where it was.

Thanks for the help!

The engine RPM signal for the Tach comes from the No. 1 connection on the spark coil. This also connects to the fuel pump relay at pin 31b which has a red/white wire on it. The fuel pump relay is just above the passenger's feet on the firewall. It is an aluminum can about 1 inch or so square. There is an identical relay, the main relay, next to it. The Bentley manual shows the one on the right is the fuel relay for the 1983 model. Hope this helps.

I've been looking like crazy, and I can't find the relay. What color is it? Does it attach to anything specific? Is it behind the heater fan houseing or something? Are you sure it's the same on a '80? There are a lot of differences between my car and any made afterwards.

I'm beginning to thing that it would just be easier to run a wire directly to the coil, but I can't figure out a way to get a wire from inside the car to the outside. Where should I run a wire to connect it directly to the coil? Where do the wires that are already there run usually? Could I just drill a hole somewhere?

It should be green. It plugs into a six wire receptacle.

Use this link

http://www.volvoworld.com/200/Section_2_5.htm

There is a picture of it at the bottom of the page.
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'80 DL 2-door

I used to have an '80 240 and the fuel pump and main relays were aluminum and located on the firewall above the passenger's feet. I was under there enough trying to get them to work! However, maybe this is a different setup from mine.

Well, at any rate the location is the same. Hopefully, Dylan has already found it and wired his tach.
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'80 DL 2-door

I ended up finding the Relay on the drivers side instead of the passenger side. Hooked it up and the tach works.

Thanks for the help everyone!

Good work. When I suggested you pick up the coil signal there, I figured it would save you the time of fishing a wire through the firewall, but I didn't count on the time it would take to find the relay. My memory for colors isn't great, but I seem to recall the one in my 79 being green too.
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Art Benstein near Baltimore

I misread what Jim had written. He said "passenger side" (correct for the '83 he referred to) and I guess I saw "driver side" because that's where it is on an '80.
Shoot me in the head.
Anyway, I'm glad you found it. Was it green?
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'80 DL 2-door