Marcos Maniacs

----- Original Message -----

From: Ron McLeod

To: MarcosManiacs@yahoogroups.com

Sent: Tuesday, December 30, 2008 12:29 PM

Subject: [MarcosManiacs] 3-liter Volvo overdrive wiring

Maniacs . . .

I am putting my rebuilt 3L Volvo engine back in the car. I have one little problem – can’t figure out how the overdrive wiring should go. Is there a Volvo owner out there who can help me with a written description, drawing, wiring diagram, or whatever?

Your help is much appreciated.

Regards . . . Ron McLeod

Marcos Mantis P8/5858

Marcos 3L GT 3V-5642

From: MarcosManiacs@yahoogroups.com [mailto:MarcosManiacs@yahoogroups.com]
On Behalf Of Denman Mike
Sent: December-30-08 3:43 PM
To: MarcosManiacs@yahoogroups.com
Subject: Re: [MarcosManiacs] 3-liter Volvo overdrive wiring

 

Hi Ron,

The wiring is actually pretty simple. I assume you know where the driver
operated overdrive switch is on your car. This switch is a single pole,
single throw which means that it is the simplest off-on switch you can buy.
One wire coming into this switch will be 12 volts positive (depending on
whether the wiring is original or has been modified, this wire goes back the
fuse box, ignition switch or some source of 12+... depending on the source,
the +12 volts may need the ignition key to be in the "on" position. At any
rate, make sure that one side of this switch has +12 volts. When the switch
is activated (flipped to the "on" position) the 12 volts positive is now on
both terminals of the switch. The wire that was previously at zero volts
should go to a relay, located?? probably under the bonnet. Mine relay was
originally located under the bonnet near the fuse terminals. At any rate,
the wire coming from the driver operated overdrive switch will come to one
of the three(or 4 depending) terminals on the O.D. relay. The other two (or
three) terminals on the O.D. relay... one of the terminals (or the body of
the relay goes to ground. One of the terminals goes back to the fuse box or
some source of +12 volts (again, the ignition switch may need to be in the
on position). Flip the driver operated O.D.  switch to the "on" position and
the relay should activate (pull in) making the remaining terminal +12 volts
(you should be able to hear the relay as it switches if the engine is not
running... thus you can verify that the +12 volts is making it to the relay
and the relay is connected properly and working) This terminal should run to
one of the two terminals on the 4th gear switch located on your transmission
(right side top as I recall). Connect the wire to either of the two
terminals as it makes no difference. When 4 gear is selected this single
pole, single throw, switch is activated which puts +12 volts on the other
terminal and this terminal has a wire that runs to the O.D. solenoid which
has two terminals. Again, connect the wire to either one of the two
terminals and connect the other terminal to a wire that goes to ground. The
wire from and to the driver operated O.D. switch can be fairly small (18
gage) because it only controls the relay and doesn't carry any real amperage
(less than 1 amp typically). The wires from the relay to the 4 gear switch
and to ground and from the 4 gear switch to the O.D. solenoid should be
fairly large since they do carry some amperage... the wire should be at
least 16 gage (bare minimum) and possibly as large as 10 gage (overkill).
The larger wires are necessary to carry the large amperage requirement, to
prevent voltage drop due to length, and the wires are in high vibration
areas and the larger wires are less likely to break. The O.D. relay is the
only confusing part of the O.D. wiring but it too is fairly simple so I will
explain it in greater detail. The relay has two sources of +12 volts (it
could "make do" with one source of +12 volts but that is another story). One
source comes from your driver operated O.D. switch. The other source could
come from anywhere there is +12 volts when the ignition switch is on. So
that accounts for two of the three/or four terminals. One of the other
terminals goes to ground (if there are 4 terminals). If there are not 4
terminals you must ground the body of the relay... run a wire from the relay
metal body to ground or bolt the relay metal body to the metal frame etc..
The last terminal goes to the 4th gear switch and only has +12 volts (at the
relay) when the driver operated OD switch is in the "on position"(with +12
volts  at the driver operated O.D. switch). . Feel free to give me a call if
you need a better explanation... worse case I can walk you through the
wiring by telephone with you having a portable phone at the car as you
connect the wires. The wiring on the cars is fairly simple but
unfortunately, over the years, previous owner modifications and normal"wear
and tear" complicate the situation.

Mike Denman

831 661-0875

 

 

On Dec 30, 2008, at 9:29 AM, Ron McLeod wrote:





 

Maniacs . . .

 

I am putting my rebuilt 3L Volvo engine back in the car.  I have one little
problem - can't figure out how the overdrive wiring should go.  Is there a
Volvo owner out there who can help me with a written description, drawing,
wiring diagram, or whatever?

 

Your help is much appreciated.

 

 

Regards . . . Ron McLeod

Marcos Mantis P8/5858

Marcos 3L GT 3V-5642