2001 S40 Turbo blown Fuse Topic is solved

Volvoblackdog · Post by **Volvoblackdog** » 14 Jan 2021, 11:23

I have a fuse that is blown on the Sensor section of the engine fuse box. Using a test light I am not getting power to either side of the fuse which leads me to believe that the relay is stuck open?

I do not have access to wiring diagram good enough to show where the wires go from the fuse box to trace the short. Any help would be appreciated. Thanks

Post by **RickHaleParker** » 14 Jan 2021, 20:00

The document you are looking for is Volvo publication TP3949202.

Volvoblackdog · Post by **Volvoblackdog** » 16 Jan 2021, 12:34

Thanks, I will take a look. I have been looking at Chilton on line. Has anything having good luck with that.

Volvoblackdog · Post by **Volvoblackdog** » 01 Feb 2021, 15:59

Okay I am still having an issue with this above problem. I have a wiring diagram now and have tested all the sensors that this fuse goes to and all seem to be fine. However, I would like to trace the short if there is one but I am not able to as the relay shuts down after I turn the key on and the relay provides power. After about two seconds the relay opens and power is shut down. I bench tested the relay and it seems fine. I am new to relays so I may not have tested it correctly. Any other ideas would be greatly appreciated.

Post by **RickHaleParker** » 01 Feb 2021, 17:37

Here is an idea: Tell us which relay and which fuse ...component numbers and which document you are using.
We are good but we are not Telepathic.

For short tracing there are tools for tracing shorts and opens in a loom. The kit consist of a transmitter and a receiver. You connect the transmitter to the wire then run the receiver along the loom until the receiver detect the location of the short or open.

You can also use the kit to trace the path of a wire without opening the loom.

The kits range in price from ~$25.00 to $200.00+ .

Here is an example in eBay.

Volvoblackdog · Post by **Volvoblackdog** » 02 Feb 2021, 14:33

I decided to try another relay in the slot for the sensor relay and found that even though the relay was working and showed at least 78 Ohms on the control side and a battery test closed the circuit. I tested the Ohms on the power side and there was no resistance but the terminals seem loose. I tried another relay and the car starts up, runs and now does not blow the fuse. I guess it was the relay even though it tested okay.

For those of you that have been following. I traced the blown fuse as follows. Battery to Fuse 11 wired to relay marked Engine Sensors in the Engine fuse box. Power out to a 10 Amp fuse number 18 , (this is the fuse that was blowing) Using a circuit breaker fuse, I was able to find that the relay was perhaps shorting the system and not allowing the sensor circuit to stay on and thus the the car would not idle.

Volvoblackdog · Post by **Volvoblackdog** » 05 Apr 2021, 23:03

I would like to re-open this issue as I have just had the problem re-surface. Although I have been driving the car for about two weeks since this issue occurred. I had to take care of some other issues regarding the drive train and had to await parts. I replaced the Left and right drive Axles as they were worn and priced new vs replacing CV boots and the cost was about the same. After doing so I noticed that the car ran fine but noticed that the Speedometer was inoperative. As I continued to drive I made my way home and the car stalled and I noticed an ABS Annunciation as well as a Brake annunciation. I started the car back up and was able to make it home but when I tried the start it again the next day, it was not starting as it should and would not idle. I checked the same fuse and it was indeed blown

To re cap. I have a sensor fuse that is blowing and this is not allowing the car to idle. According to the fuse box schematic fuse 11 routes to relay 2/14 which connects to fuse 18, the fuse that is blowing. These items are as follows:

Oxy Sensor front and rear.
Crank case breather
Turbo control Valve
Idling valve
Leakage diag. Pump
Evap. Valve

I checked these components and they seem to all be working properly, However I do not have the equipment to test each sensor correctly.

Thanks for any and all help.

Thanks