Hello all--I'm a long time tinkerer and mechanic, new to this site and to this particular Volvo. The customer complained of the battery going dead when sitting for a few days. I checked the current draw with everything off, and there is a constant .78A drain. Pulling the fuses one at a time quickly showed that the drain was in the circuits powered by the No. 7 fuse. No. 7 is hot at all times, and sends power to the clock and to the fuel pump relay. Pulling the fuse takes away the drain, as does removing the fuel pump relay. The Volvo wiring diagram shows that the fuel pump relay is normally open to terminals 87 and 87c. However, the relay that was in the car is normally closed to terminal 87c (labeled 87a on this relay, a Bosch P/N 0 332 209 158). I figured that someone installed the wrong relay, so I ordered a new one from swedishautoparts.com. The relay I received is a Bosch P/N 0 332 209 150, and is also a NC relay, just like the one that was in the car. So either relay, with the key off, is sending power at all times to the Auxiliary air valve and Control pressure regulator. Testing these components separately shows a draw of .27A for the former and .51A for the latter, for a total draw of .78A. Seems to me that a NO relay as shown in the diagram would fix the problem. Since I'm not familiar with this car, can anyone shed light on this for me? Did I receive the wrong relay?

 

Well, the original Bosch numbered relay is the correct relay for the 76-77 CI Volvos. However, those five legged relays can only be set up a limited number of ways from the factory. Assuming the amp load rating is the same and the legs are the same as to what does what, the replacement should be fine. You've nicely narrowed down the search. That era car is normally free of the biodegrading engine harness insulation of the early 80's but still...the common thing would be bad insulation somewhere or possibly a failing ignition switch energizing components. Or...at some point in the past, prying hands mis-wired something. Sorry I can't be of more help at the moment...when I get to work tomorrow I'll do some research; we should have detailed schematics in the old Volvo green books for that year.
Not sure what you paid or how long it took to receive but my experience with SwedishAutoParts is they are higher than a Georgia pine on stuff. Here's the link to the relay at one of our sponsors...
http://www.fcpgroton.com/product-exe...ategory_id/171

Actually, you can directly access the same Green books we have here...
http://www.k-jet.org/documents/greenbooks/200-series/

 

Thanks for the reply. I looked the relay you linked to, and it's the same--normally closed to terminal 87a. This would send power to the Auxiliary air valve and Control pressure regulator at all times. Unless these two components had NO draw, that's going to make for a full time draw on the battery. I have the green book of wiring diagrams; the image I posted is from the Volvo book. Check out the diagram and see what you think. Looks to me like the relay in the diagram is one like THIS, normally open to both contacts.

 

Thought I would post a follow-up. I ordered a normally open relay with dual contacts, Del City P/N 73996 and installed it. There is now no drain on the battery, and everything is working correctly. Looks to me like the relay being sold as the OEM replacement is incorrect. Maybe this will help someone else having the same problem.