Fitting towbar electrics to a 1991 940SE estate

I know that there are lamp out detectors on the tail lights and brake
lights, so how do I connect the towbar electrics so that I don't upset
the detectors?

Cheers

Peter

 

In an earlier contribution to this discussion,

By tapping into the cables *upstream* (battery side) of the bulb failure
detectors.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

 

Roger,

Thanks for that.

Next silly question - where are these detectors located and what do
they look like? Is there one per circuit?

Cheers

Peter

 

In an earlier contribution to this discussion,

Don't know for sure, but http://www.volvotechinfo.com/WD123/ might offer a
clue. This has wiring diagrams for 940's - but only for 1994/5 - but they
are probably similar.

It looks like there's only one unit, and that it's a circular can at one
corner of the relay panel, behind the radio. (See the section on relay
location etc.)

Groups 35 and 38 (further down the document) have more details of the
wiring.

If my reading is correct, the only rear lights to be monitored are the brake
lights. You would need to tap into the yellow and brown wire - after the
brake light switch (3/9) but before the failure detector unit (7/75). You'll
probably need to refer to the list of components (at the bottom of the
contents list) in order to de-code the diagrams.

HTH!
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

 

When I installed mine, I didn't. I rarely tow a trailer so I just put up
with the bulb failure warning coming on. If you tow regularly you can do
as another poster suggested and tap in ahead of the failure sensor but
that involves running the wires all the way up to the front of the car.
Not an enormous task but you do have to pull a bunch of interior trim off.

 

In an earlier contribution to this discussion,

Another possibility is to power the trailer brake lights via a relay. The
small current drawn by the relay coil may not upset the bulb failure sensor
(although there's no guarantee of that!). You would still, of course, have
to run a 12v feed from the front of the car for the brakelights themselves -
unless there's already a sufficiently heavy duty permanently live cable at
the rear.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!