In the process of replacing factory HVAC with a Classic Auto Air system. Came across a couple of relays and I'm trying to confirm their function. One is part of the stock heat/a-c wiring harness, and one appears to be connected to the large guage/blue-yellow wires that are connected to the rear window defroster. Pic link below -- the one I think is heat/a-c related is the one with the schematic on the side (black/white letters) and the one I think is rr window defrost related is the blue one. Can anyone confirm my guesses? I don't have a wiring diagram for the car --- may have to remedy that!

http://i937.photobucket.com/albums/ad214/MichaelYount/New%20HVAC%20System/relays_zpshnszio8o.jpg


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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

At a glance the case color and wiring of the blue relay indicate it's for the overdrive.

If the car is an automatic that shoots the hell out of that theory.


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'80 DL 2 door, '89 DL Wagon

I think your guesses are right. But if you want to be absolutely sure, give the colors of the wires on the relay sockets. The boxes themselves are not that uniquely decorated, but the wiring is like a fingerprint.
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Art Benstein near Baltimore

Be careful of your tongue: It's kept in a wet place and could easily slip.

Thanks Art -- I found schematics tonight - the GREEN BOOK stuff. I'll get back to you tomorrow with colors.
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

Last night I started to edit my post to add the link to k-jet.org but when I looked there, I did not see the '82 wiring diagram manual. I have a copy of the '81. Glad you found yours, as it makes certainty out of what otherwise would be guessing once you match up the drawing with your car as built.

Your aftermarket climate project is, I think, groundbreaking in the 240.
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Art Benstein near Baltimore

"Everybody's got to believe in something. I believe I'll have another beer." (W. C. Fields)

Here we go....

Blue relay - Hella 50a; 87=double yellow; 86=black; 85=red; 15=double blue; 31=black/chassis ground nearby. All wires pretty good size 14 gauge, maybe 12. The black wire grounds to the passenger side steel dash support/console surround. And the rest of the harness is in the OEM black sheathing and heads down into the passenger side footwell alongside the passenger side rear seat heater duct.

Black relay - 15=yellow/blue stripe; 87=bright green; 85=brown/chassis ground nearby; 61=red; none of the wires as big as the ones on the other relay. This harness comes from the driver's side/fusebox area and is clearly part of the same harness that went to the fan control switch.

I suspect, Art, it may be the first, certainly one of the first, to have aftermarket A/C added. The 82 systems just weren't designed to effectively deal with the heat/humidity of the S.E. USA. I'm finally remedying that. If you'd like to follow along -- go here - http://forums.corral.net/forums/southeast/14792-anyone-east-tn-corral-757.html . Starts on page 752. I'm also pulling out the 5.0L engine that's been in the car since 1996 and putting an LS3 in --- so there's some coverage of that as well.

Bulletproof - I'm the second owner and the car already had a T5 tranny in it when I got it, but I don't think it had OD on the original tranny. Just a guess though.

Oh - Art - I found 'my' schematic in the online greenbook pages....
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

Yup, Don nailed it from your photo on the M46 relay. The wire colors you provided make it certain.

One thing that AC relay does, you might, just possibly, find useful in your new system. The D61 terminal "reads" the fact the motor is running by looking at the alternator's output.

The relay is made to stay disengaged until 10 seconds of alternator output have occurred, ensuring the motor is successfully started and idling before allowing the compressor to further load it. At least that was the purpose of it in the 82 as it was originally built. Your V8 probably doesn't even notice an AC compressor.
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Art Benstein near Baltimore

The quickest way to double your money is to fold it and put it back into your pocket.

A nice thought....but the new system will handle the a/c and compressor operation. Instructions had me mock everything up hooked up to a 12V battery and run through all the modes of operation to program the system. And of course, it confirms that everything is working correctly. So the entire Volvo system and wiring/relays can come out. It's even fused separately, so no need to keep any of the old system. Between the efficiency of the 7-piston Sanden and about 280 lb-ft at 800 rpm with the new motor, shouldn't have any problems with the A/C system overwhelming the engine.
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

MY wrote--"I'm the second owner and the car already had a T5 tranny in it when I got it, but I don't think it had OD on the original tranny. Just a guess though."
In a T5 gearbox 4th gear is a direct 1:1 ratio. 5th gear is an overdrive ratio. I think the Camaro T5 I'll be using in my VolvOldsmobile V8 has something like a .68 :1 ratio. I think the Ford versions may be a little different. -- Dave

The 5.0L Stang T5's have a .675 5th. My tranny is the T5z which has a .625 5th.
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82 242 5.0L; '10 Cayman S; '15 Honda Fit

1307064 is definitely an AC relay part number.

In spite of the T5, the blue relay, as you have described it, is exactly how the M46 OD relay is wired. That relay was first used in 1981 models.

Sounds like the PO was a bit lazy. Might as well remove it and the associated wiring.


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'80 DL 2 door, '89 DL Wagon

For anyone else following along, here's the best schematic I've found....

http://www.davebarton.com/pdf/240_M46_Overdrive_Harness.pdf
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

....and it turns out that the wiring under the carpet - used to go to the shift knob and the OD solenoid itself - had been terminated but never removed. So out it all comes -- and I get another used relay, in addition to the A/C relay, to add to the collection.

Thanks to all for your assistance.
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

Yes. There are intermediate connections for all but the wire to the dash light which I'll wager is still intact.

It's easy enough to remove from the 12 pin connector. Just don't confuse it with the other yellow wire. OD is 4. Temp gauge is 2.


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'80 DL 2 door, '89 DL Wagon

Yeah - I sorted that out yesterday and found a surprise. All the way to the right on the row of lights at the bottom of the cluster is an "OD Off" light -- I can read/see it by shining a light on the outside of the cluster. I thought that light would be illuminated with 12V+ to the yellow wire. However, when I hooked a 9V battery up to the yellow wire in question, I was surprised to see a nice little green light that just says "OD" more in the middle of the cluster. That one you can't read from outside the dash - it has to be backlit; all these years I actually thought that space/light in the cluster was un-used.

I presume that one or the other of those lights was on at all times when the car was running and both on for test with ignition on?

Anyway - left the yellow wire loose and marked --- may find a use for that one just to signal me that some yet unidentified device is powered. Perhaps have it light up when the cooling fans come on for the a-c or when a-c clutch energizes. Or maybe have it light when the cruise control is energized. I marked temp gauge, oil press. idiot light, tach feed, oil pressure gauge, oil temp gauge and alt. light (alt exciter) wires when pulling the 5.0L out. I removed the blue OD power feed all the way back to the fuse box - #11 I think.

I also left the large gauge white/black stripe wire that fed power from the fuse box to the heat/a-c fan in place -- it comes off #3 25A circuit --- it'll be perfect to feed power to the new HVAC system which is fused with a 20A circuit. That will power the fan, the heater control valve and all the air diverter functions.
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

The green OD light is the one for the M46. With everything hooked up as Volvo intended, this light would only display when the car is in fourth gear and overdrive is engaged.

The OD off would be for the AT w/ OD, where equipped. Light is on when OD is off. Seems backwards somehow. But that's how they did it.


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'80 DL 2 door, '89 DL Wagon

The 240's with the 4-speed AW 70/71 automatic (really a 3-speed with hydraulically operated OD) were set up so that the default was OD on. You could press the OD-Off button on the gear lever and a solenoid would cut out the OD, at which time the OD relay (a very different unit from the manual trans OD relay) would turn on the dash warning light. This probably was because the Swedes had visions of unaware drivers howling down the freeway in 3rd gear, perhaps after unintentionally hitting the button.

Pressing the button again or switching the ignition off then on, would reset the relay to allow OD on - and kill the dash warning light.

I'm following your engine swap with interest. My LT-1/T56 powered 700-wagon in "refrigerator white" is an even better sleeper than a 240 sedan. Especially with white-haired Grandpa at the wheel. Plenty of fun shocking the hipsters in their 3-series.

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Bob: Son's XC70, my 83 244DL, 89 745 (Chev LT-1 V8), 98 S90 (recently sold) and 2010 XC60. Also '77 MGB and four old motorcycles

Thanks for education!
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82 242 6.2L coming...; '10 Cayman S; '15 Honda Fit

Thanks for the quick reply. May have trace out that OD harness and see where it goes - none of that wiring is on the underside of the car, that much I know.
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82 242 5.0L; '10 Cayman S; '15 Honda Fit