Forum;

Hello from the folks at the left end of the Brickboard Forum list (where we don’t have seat warmers or air-bags in our cars, can do a tune-up for under $50 - if we’re not buying two $60 air filters(!), and the entire vehicle wiring diagram fits on a single page!).

I understand there is a relay or circuit used in the 240 series to control the OD, which self-cancels, that is, if one is in 4th gear +OD and shifts out of 4th, there is a provision which automatically also deselects the OD activation, so that the next time 4th is selected, the OD doesn’t automatically drop in unwanted (like it does with the simple control system of the oldies). Can someone please confirm this; provide part numbers and circuit and any other info or details on this. I wish to show it for control of an OD in 122 or 1800 vehicles. These vehicles do not have this feature, but it is obviously nice to have and recommended, especially if it can be simply and painlessly retrofitted. Gearboxes on these vehicles do have an isolated switch which closes when 4th gear was selected.

Any help on this is appreciated. TIA!

Ron-

I run a 240 OD relay from an '81 M46 in my '65 122 with a M41 since 2003. The writeup has been floating around BB. Bob S. (Sil) has modified it a little for his 544. I can send you the writeup, or just build you one.

email me at malloy1atprodigydot

Paul

BTW- I use the high beam switch on the turn signal stalk to activate the OD (kind of a paddle shifter). If you remove the sugar cube relay in the diagram, those two wires become your momentary switch wires.

Paul;

Thanks for info...if you could forward your notes and any other details, I would like to study the circuit a bit more.

Cheers

Ron-

I'll send you the write-up later, but this is from the green books. You can get all the greenbooks for the K-jet cars at k-jet.org

It's pretty good!

Paul

Hello,

To use the later O/D relay with the self canceling feature from a later Volvo you need to use a momentary switch as a O/D triggering switch, preferably a switch that can handle positive voltage, but that is not manditory.

There are several different relays that are used on Volvos of several colors, but I prefer the early blue one for 1981-1984 Volvos as it has a standard connector pattern that I can easily get a pigtail that fits.

On pre-1970 1800, you can use the ground signal from the stock O/D column switch by using a stardard relay to trigger the blue O/D relay.

On all 122 and all 544, you can use the ground signal from the headlight flasher switch from the turn signal switch, to trigger a relay to run the O/D relay IF you are not using it to already trigger the headlight flasher.

Or you can buy a shifter knob with a switch already in it from a performance catalog or shop and this can be done on all the 1800e/es, 122, 544 and 140/160 or you can add a momentary switch on the dash or steering column cowl.

My favorite conversion is to use a 1974 or 1975 shift cover(1975 won't fit M400/M410). This allows the use of a chrome upper shifter handle, knob and O/D switch from any 1981 and later Volvo that used a "J" style O/D.

You have to drill a hole in chrome shifter handle that is 90° to the factory hole to properly mount the later handle onto the shiter stub shaft from the 1974/75 shift cover, but it uses the same size retaining pin.

The 74 shift covers can be used on all M41 and M410 transmissions.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90501

... in my post below, where at the end I added the following:

Seems like most any simple relay would work, with a push-button switch (ON) and grounded thru the 4th gear switch (the "self"canceling" part).
Solenoid current would be a consideration.

That's dead wrong. A special "latching type" relay is required. The simpler relays would do just what you don't want — they would re-energize as soon as 4th gear was re-established.

Once the ground is lost (by going out of 4th gear), the latching relay I described will not automatically "switch on" again when 4th is re-engaged. The energizing pulse from the OD push-button switch is also required.

The simple On/Off switch on pre-'81 OD's that Randy suggests would also allow the unwanted "automatic" OD re-engagement you want to avoid. You need the combination of a PB switch AND the later (electronic) relay.



P.S. Apologies for the duplicates below. The BB system was stalled for a short time I guess.
--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Lucid;

Thanks for info!

I should have given link to what I have written so far: http://www.sw-em.com/OD_Retrofitting.htm#OD%20Wiring

ALL three have OD control circuits known to me have "unwanted reactivation"...because in each circuit, the 4th gear switch is simply in series with solenoid...addition of a sequence dependent function is necessary...I expect the 240 relay has that built in with electronics...

Thanks again to all for responses...I need to study these further.

"..because in each circuit, the 4th gear switch is simply in series with solenoid..."

I see that in all 3 of your OD circuits. IMO that's key to the problem. It should be in the relay COIL circuit as with the 240 M46 OD.

Your OD 3 is close, and would work if the 4th GS was put in series with the Momentary Dashboard switch. That would make a logical "AND" of both switches be required for relay (and thus solenoid) control. Re-engaging 4th would not power the solenoid until the momentary PB switch was pushed again.

That's essentially what I suggested, except that the OD momentary switch is on the + side of the coil while the 4th GS is in the coil ground side. And the later "electronic latching" relay, eliminates the older mechanical type.

Thinking further on it, I believe both later style Auto OD relays can be wired to work also, and would be more readily available at the Man's Mall for the DIY'er. Post back if you want the details.
--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

The overdrive in the M46 is enabled only in fourth gear and this is controlled with a switch mounted on the transmission. Only when the fourth gear switch is closed will the overdrive engage, and likewise as soon as the switch opens when shifting out of fourth the overdrive disengages.

The switch screws into the transmission on the passenger's side. I assume that the earlier cars did not have this switch?

Randy

If you have the 4th gear switch, I think you want the OD relay for 240 w/M46 from
'81 - '84. Terminals & functions below:

15 Voltage in

87 Controlled voltage out to solenoid and OD light

86 Controlled (push button) voltage to relay coil

85 Coil ground via 4th gear switch
Relay drops when 4th gear switch opens.
Won't pick again till 4th gear switch closes and relay 86 is pulsed again.

Relay # 1259750-6 $76.15 MSRP $54.29 "Internet price" at Tasca Volvo.

This is a Blue relay. FCP (new site) lists only the Orange one for Auto OD, which won't work as described above.

Seems like most any simple relay would work, with a push-button switch (ON) and grounded thru the 4th gear switch (the "self"canceling" part).
Solenoid current would be a consideration.


--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

If you have the 4th gear switch, I think you want the OD relay for 240 w/M46 from
'81 - '84. Terminals & functions below"

15 Voltage in

87 Controlled voltage out to solenoid and OD light

86 Controlled (push button) voltage to relay coil

85 Coil ground via 4th gear switch
(relay drops when 4th gear switch opens.
Won't pick again till 4th gear switch closes and relay 86 is pulsed again.

Relay # 1259750-6 $76.15 MSRP $54.29 "Internet price" at Tasca Volvo.

This is a Blue relay. FCP (new site) lists only the Orange one for Auto OD, which won't work as described above.

--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

If you have the 4th gear switch, I think you want the OD relay for 240 w/M46 from
'81 - '84. Terminals & functions below"

15 Voltage in

87 Controlled voltage out to solenoid and OD light

86 Controlled (push button) voltage to relay coil

85 Coil ground via 4th gear switch
(relay drops when 4th gear switch opens.
Won't pick again till 4th gear switch closes and relay 86 is pulsed again.

Relay # 1259750-6 $76.15 MSRP $54.29 "Internet price" at Tasca Volvo.

This is a Blue relay. FCP (new site) lists only the Orange one for Auto OD, which won't work as described above.

--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Volvo Green book for the electrical system, only way to go.

jorrell
--
92 245 250K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

Yes, the M46 cars (1986 & under) have this OD. I'd think FCPGroton website would have the part numbers (I don't, sorry). Or search here on OD and M46 OD