SAAB WIS ONLINE

(03-08-351) Intermittent trailer lighting

Symptom: Trailer lighting is intermittent

TECHNICAL ADVICE - Quick information for your help
Bulletin Nbr: 03-08-351
Date: ........... Augusti 2003
Market: Alla
Intermittent trailer lighting

Cars affected

Some Saab 9-3 (9440) M03- with towbar and where the car is used together with a trailer having a 7-pin connector

Background

13-pin connection for trailers is a new standard which provides many advantages for the user, including the possibility to connect the trailer's power consumers to separate connections adapted to higher power consumption and to have both rear fog light and reversing light on the trailer. The Saab 9-3 Sport Sedan (9440) is built in accordance with this standard. A trailer with a 7-pin connection can be connected via an adapter.

When using a trailer with a 7-pin connector connected according to one of the following alternatives


• all exterior lighting is connected to either pin 5 or 7 in the 7-pin connector

• extra power consumers (e.g. heating fan) are connected via the trailer's connections for lighting (pin 5 or 7 in the 7-pin connector)


the load becomes too high in the car's REC and in the electronic module for the trailer. This results in the electronics switching on and off which means that the trailer lighting is intermittent.

Symptom description

Trailer lighting is intermittent



Procedure

Alternative 1 (recommended)

Replace the trailer's connector and wiring harness with the 13-pin version. Extra power consumers are then connected to pin 9 or pin 10.

Pin no.
Function
Max. load
1 Direction indicators L 6 A (short)
2 Rear fog light 30 A
3 Ground
4 Direction indicators R 6 A (short)
5 Exterior light R 6 A (max. nominal load 50 W)
6 Brake lights 30 A (short)
7 Exterior light L 6 A (max. nominal load 50 W)
8 Reversing light 25 A
9 +30 (constant power supply, max. power consumption 20 A) 20 A
10 +54 (power supply via car's ignition switch, max. power consumption 30 A) 30 A
11 Ground for pin no. 10
12 Not used
13 Ground for pin no. 9


Alternative 2

Make an adapter harness with a 7-pin female contact for connection to the trailer's connector at one end and a 13-pin male contact for connection to the car's connector at the other end. The connectors are connected together as follows:

7-pin female contact, pin no.
13-pin male contact, pin no.
1 (Direction indicators L) 1
2 (Extra power consumers) 9 (constant power supply, max. power consumption 20 A) or 10 (power supplied via car's ignition switch, max. power consumption 30 A)
3 (Ground) 3
4 (Direction indicators R) 4
5 (Exterior light R) 5
6 (Brake lights) 6
7 (Exterior light L) 7