Tom Gierisch

I don't know what you mean by putting two extra ABS sensors in the single axle. I don't know what a toner unit is.

Dear Mr. Never Easy, Thank you, thank you, thank you. One two wire connector was already disconnected on that harness. When I disconnected the second connector (4 pin) it cleared the faults and fuse 12/27 are not blowing. My assumption is that I do not need anything related to Qualcomm. I hope that is the case. I really appreciate your time, knowledge, and skill to figure that out for me. I would have never have found that on my own. Can I assume from your schematics that the Qualcomm is the only thing on those two circuits? I'm not sure if this was related to my intermittent loss of power but I am so pleased to not have fusses blowing, not knowing what they were for and not knowing why they were blowing. This was a learning exercise and I appreciate everyone's efforts. I also have lot's of new wire loom that looks good and found a few wires that were in need of a little TLC. Now I think I'll tackle my ABS issue.

Weather is not to good today so my time outside has bee limited The fuses have always blown with the drivers display disconnected. I'm not sure if that means if the fault is between the display and the fuse panel or not. I guess I would be leaning toward the assumption that it is between the fuse panel and the drivers display if I had to guess. Both fuses read .85 ohm's to ground on the load side of each fuse with the multi meter set on 20K scale. ( I'm not an expert on resistance to ground and I'm not sure what that means) I would guess not good. When I tested the load side from fuse to fuse (12/27) I get zero oms to ground. That tells me the load side of the two fuses are common. I don't think that is a good thing! I'm still looking at wire in the engine bay, haven't found anything out of order yet. The wiring under the dash looks in very good shape for a truck that is 20 years old. The insulation is soft and pliable with no cracking . I know that doesn't mean there can't be a problem in that area just saying Volvo has some good wire. While waking up this morning I had a flash back to 2005 when I had the truck singled out. As I said earlier I think the circuit on fuse 27 always had a fault. As I remember I had an ABS warning light on after the front rear axle was removed. The shop foremen asked me if that light was on before he did the work and I told him yes and I believe it was. I was never able to get the light to go off after making several suggested checks, so I did a Larry Zigler for any of you that have been around that long. I removed the bulb from the panel and installed a burnt out bulb so I didn't have to look at it. Since both of these circuits (12/27) have to do with the instrument cluster maybe I should move my search to the rear axle. Thoughts on how to trouble shoot an ABS system are welcomed.

Thanks for all your input. The harness that comes off the fuse panel makes a 180 under the dash and splits with most of the wiring headed towards the drivers side. As you probably know the harness are massive and near impossible to lay your hands on. I could see the wires coming off the two fusses. There are actually three wires which quickly disappear into a large bundle which would be near impossible to trace. I'll check the resistance to ground on the load side of the fusses and lamp test as suggested. I'll start daylighting the harness in the engine bay and start examining each wire. Maybe I'll have better luck on that end. This could be worse than looking for a needle in a hay stack. My build date is October 1998

Checked battery voltage this morning. Volt meter read 17.5 V. Obviously that can't be right. Got another volt meter, battery voltage read 12.7 V. Started engine, 14.3 volts at the alternator about the same at the batteries. I guess the good news is I don't need to go to Phoenix to buy a new alternator.

I have been pretty busy for the last few days trying to run down my short. 1. Checked wiring under the hood where work was recently done. I did not find any issues. 2. Pulled all the lower panels under the dash including the dog house. Inspected wiring, removed some wire ties, removed screws securing fuse panel, visually inspected wiring, looked for signs of a ground to chassis, and wire to wire. Tried to move wire harness a little bit to see if that would help. Removed and cleaned all ground wire to the fire wall of the engine. Replaces some worn wire loom but no obvious problems. Since I had the batteries disconnected during this exercise I cleaned all the battery terminals any wiring before reassembling. 3. After starting the engine both of my problem fuses #12 and #27 blew immediately. 4. After the fuses blew I checked the voltage at the fuse panel, 19.5 volts. Then checked at the alternator, 19.5 volts. That does not sound so good. Sounds like I need a new alternator. I believe the voltage should be 14/14.5 volts. This may not be the answer to my problem but I think it has the capabilities to create more problems. What do you think?

Started my project yesterday. Found a few surprises but none solved my problem. I knew it would not be simple and I'm usually not that lucky. I have not been successful to find the link to Dale Bruss's wiring diagrams. Can someone help me out.

Thanks for all of the replies. I'm in Sedona AZ and looking forward to the good weather after leaving MT about ten days ago. The engine ran fairly well on the way down. I definitely have an electrical issue but I'm not convinced it's directly related to poor intermittent engine performance. The hunt will start today looking for a fault. Again thanks for your comments and I'll post updates on what I find.

I own a 1999 VNL Volvo with a Detroit 60 series engine. I have owned this truck since 2005 and always had an electrical gremlin. My drivers display has never worked. No big deal most don't. I had one fuse that blows immediately which is #27 5A for drivers information center. I believe I have had this problem from day one with this truck. It doesn't seem to effect operation or engine performance. Recently I have a second fuse, #12 5A for the drivers information center which now blows immediately when the engine is started. This fuse/problem has caused loss of power making travel difficult. I have very recently had the air to air cooler replaced along with srs and trs sensors. The radiator and a/c condenser were removed to complete this work and A/C was recharged. Fuse #12 blew for the first time shortly after this work was done causing loss of power. After discovering the blown fuse I replaced it and the truck ran fine. I drove from northern Montana to Moab UT with no issues. Upon arrival in Moab the fuse blew again. With that fuse blown I have loss of power again. The fault remains and fuse #12 blows immediately when you start the engine. I have removed all wringing harnesses from the instrument cluster and replaced the fuses. Both fuses blow when the engine is started even with the wiring disconnected to the instrument cluster. I plan to try and head south today and see how things go. Your thoughts and advise are welcome. This problem may be beyond my level of expertise. I'm headed towards AZ. If anyone knows of a shop with a good electrician it would be appreciated.