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Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 3321
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
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Have an 01 ***** ***** 9500 with cat c12 the dash gauges

Customer Question

Have an 01 ***** ***** 9500 with cat c12 the dash gauges wont self check
JA: Thanks. Can you give me any more details about your issue?
Customer: my name is adam
JA: OK got it. Last thing — Technicians generally expect a deposit of about $54 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  ][\][iCk0411 replied 1 year ago.

Hi, my name is ***** ***** I would be glad to help you today. Welcome to Just Answer! Would you like me to call you? if so just press the request tab, or I can initiate the call. In the meanwhile could you tell me what are the gauges doing if they don't sweep? are they just sitting on the bottom? or going all the way around and maxing out? any other issues at all? are all gauges affected? Thank you

Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed
Customer: replied 1 year ago.
The gauges are all over the place speedo is stuck at 55 the oil press is fine and the air is fine too. When you turn the key on the gauges do not cycle. the brake light and buzzer is the only light illuminated. The 6 pin connector will not allow a scanner to power up. i checked the 6 pin connector with a power probe the center pin is at 8.8 volts the other 3 pins are showing voltage as well idk if there is a grounding issue would u have a wire diagram
Expert:  ][\][iCk0411 replied 1 year ago.

Okay, I can see if I can pull up a diagram but in the meanwhile I would start super simple with these dashes. Many of times before I have found it is exactly what you are suspecting as a ground issue. On your 9500 there is two spots that the interior, or dash are grounded to the chassis. there is a ground post on the firewall on the driver's side, and the passenger side about mid way up and its a post that is secured on both ends with all the grounds. I would recommend removing all wires on the outside, and inside of the firewall and cleaning all connections, take sand paper, or something abrasive to sand the actual aluminum of the firewall. These dashes and interior circuits are extremely sensitive to ground losses. Clean and re-assemble both sides, make sure the bulkhead is nice and tight when you re-assemble.

Customer: replied 1 year ago.
Also on fuse 22 when you insert the fuse it faintly brings the brake light on and the buzzer doesnt matter if the key is on or not seems like a short and and fuse 22 controls the gauges. Also i would like to add the truck will not run because of this issue
Expert:  ][\][iCk0411 replied 1 year ago.

Yes, that is correct that it could be a short in the circuit. The fact it isn't starting could be two issues possibly. How did this defect get to this point? Was there any other symptoms? Did it just not start today, or broke down while in service? Next thing if it wont start would be to check the ECM fuses at the batteries. Can you confirm this exact unit? 2001 Navistar 9500 with a c12 correct?

Customer: replied 1 year ago.
The truck was driving down the road and shut off. I had a person with a bosch computer try reading the codes his computer wouldnt even power up. These batteries are brand new and i cleaned the connections to them. Like i said i power probed the 6 pin diagnostic port. i had 8 volts on center pin on the ground pin i had 12.8 volts on the power pin i had 12.8 volts and on the negitive data pin i had 1.2 volts. The truck is a 2001 sterling 9500 with a c12 cat.
Expert:  ][\][iCk0411 replied 1 year ago.

My apologies for that, the first part I mentioned about the grounds on the firewall was for a Navistar. Okay, now that we are on the same page I've located a simple diagram I can send. Looks at first glance that all the grounds, and power is split for all the gauges at the ignition switch. Would be a good first place to inspect if there is any wires rubbed, possibly shorted on the drivers side behind the key switch. With the lights and buzzer acting up you may have to eliminate each circuit individually. The light switch is on that side of your dash as well so I'm wondering if you open up that side of the dash to inspect, you may find either rubbed, melted, or rotted wires together to get all these symptoms is very uncommon.

Customer: replied 1 year ago.
are you sending the diagram? and what do you make of the readings at the diagnostic port?
Expert:  ][\][iCk0411 replied 1 year ago.

The way this site works is the experts don't receive any proceeds unless the question is rated. I will send the diagram and continue to walk through the issues for no further cost if you can rate the question. The readings are there, I'm thinking one of those ports shouldn't have power and could be rubbed, shorted with the circuit 22. It more than likely isn't a co-incidence that the issues are all originating from the driver's side dash where the plug in, ignition switch, and dash are located. you need to do a vey thorough visual inspection in behind all the wires, with how old the unit is I would check for rot at that diagnostic port, even try unplugging the ignition switch and try the fuse to see if it changes. possibly an internal short in the ignition switch.

Customer: replied 1 year ago.
Do you know what size bolt hold the computer connector to the ecm that's actually part of the plug
Expert:  ][\][iCk0411 replied 1 year ago.

Not entirely sure Sir. Usually if its either a 8 or 10 MM. you can assume its more than likely a metric size.

Customer: replied 1 year ago.
I heard it might be an Allen key.
Expert:  ][\][iCk0411 replied 1 year ago.

Yes, could be as well. If it is then it will be a metric size. Almost everything on a CAT motor is Metric.

Expert:  ][\][iCk0411 replied 1 year ago.

How did everything look in the dash so far? Find anything out of the ordinary so far?

Customer: replied 1 year ago.
In desperate need. Of wiring diagram from fuse panel to dash and dash to outside.
Expert:  ][\][iCk0411 replied 1 year ago.

I am unable to get that for you so i'm going to Opt out of the question and see if anyone else can assist you further. Goodluck!

Expert:  Jeremy replied 1 year ago.

My name is ***** ***** I will assist you with your question today.

I'm an independent contractor and I don't get paid until a rating has been made. No rate, site gets it all.

We can go back and forth as needed to help resolve the issue you are having. Follow ups are free after ratings, so rate in confidence!

Do you still need the cluster wiring diagrams? I can send you that section of the manual off of the Freightliner site if needed.

This question has been locked for a few days and unlocked today so I'm not sure if you are still needing assistance or not.


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Once an answer is provided, you should see a rating screen. Please rate my personal service to you. The ratings are my personal feedback,

they are not the site feedback.

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