960: no start - no spark, no fuel, no communication via OBDII port?

crashtest · Post by **crashtest** » 03 Apr 2016, 15:42

93Regina wrote:
crashtest wrote:If the ECU is dead - would pin 30 in the main fuel injection relay
Diagram shows a direct connection between battery, fuse, and pin-30

Go to fuse-4, is there voltage on one side? If true, then disconnect battery, and ohm spec from other side of fuse to pin-30

12V at fuse 4. Broken circuit from fuse 4 to pin 30 on fuel and also ignition relays (2/32 and 2/46). Would the ECU be able to sever this? I don't understand how these two wires could have been cut while parked, but all other connections from the 50A fuse block to the relay box are functioning.

93Regina · Post by **93Regina** » 03 Apr 2016, 21:06

crashtest wrote:...Broken circuit from fuse 4 to pin 30 on fuel....

All I can say is trace the circuit, and fix it.

Fuse #4's circuit must be delivering power to ECU at pin #26, ignition switch via Y-R wire, and relay 2/32 at pin #30...so see page 50 in that wiring diagram, and trace out,

crashtest · Post by **crashtest** » 06 Apr 2016, 11:01

What I don't understand from the diagram is: the circuit goes from fuse 4 to pin 30 on relay 2/32 and to the ECU. If the ECU is toast, the relay would still see 12V, right?

93Regina · Post by **93Regina** » 06 Apr 2016, 11:53

crashtest wrote:...fuse 4 to pin 30 on relay 2/32 and to the ECU. If the ECU is toast...

If fuse #4 is not sending current to pin 30, then this circuit is toast, and needs to be repaired.

At the arrow point in this first diagram is where several wires obtain current from fuse #4. The wires' color at this junction point is white, and the wiring diagram says this is a branch point called "33/100," which is located in next photo.

Chances are, this junction point is messed up, which means this box will have to be taken apart...and I know nothing about this process. But, if you could find this white colored junction point, one could insert current there, and see if everything works.

I have taken apart a Ford box like this, and there is a technique to do it. On the interent, there is a web site where one can ask a Volvo mechanic, for a price. It's possible this issue has happened before, and if so, Volvo may have a TSB, and maybe a free fix for it...a big maybe.

: Capture.PNG (47.99 KiB) Viewed 1283 times

: Capture.PNG (62.99 KiB) Viewed 1283 times

crashtest · Post by **crashtest** » 13 Apr 2016, 07:05

Just following up for anyone who searches for a similar issue. Problem was resolved, broken wire between fuse 4 and junction 33/100 (as suggested by 93regina). Ran a new wire and all is well. Didn't want to open the 20 year old bundle of wires so ran the new wire along the outside of the existing harness.