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Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 2721
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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1987 Peterbilt wiring schematic 379. The switched side of my

Customer Question

1987 Peterbilt wiring schematic for a 379. The switched side of my fuse panel is dead
JA: We'll do all we can to help. Tell me a bit more about what's going on so the Heavy Equipment Mechanic can help you best.
Customer: I have no blower motor no Jakes no wipers the volt gauge stays at 12 volts even when the key is off
JA: Is there anything else the Heavy Equipment Mechanic should be aware of?
Customer: We checked fuses can't see any broke wires batteries are good terminals are clean connections are tight
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Heavy Equipment Mechanic about your situation and then connect you two.
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 4 months 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.

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!

There are 2 diagram sets that Peterbilt has for this truck I will load them both for you. One is the main control box which shows the whole truck and the other is the split. This is all Peterbilt has for the year of your truck. The rest has been purged from their system, unfortanetely.



This is just how Peterbilt did the wiring diagrams up until 2005 where they actually split them more. I hope these help you out.


You want a 5 star service and I want to provide a 5 star service. Please consider that I don't know your skill level as well as I can't see, touch, smell, hear the vehicle/machine in question. Please provide as much detail as possible and I will provide as much back.

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.

Thank you for allowing me to assist you through Just Answer!


Expert:  Jeremy replied 4 months ago.

I see you viewed this and this is still showing as an open question due to no positive (3 stars or more) rating.

Were you not pleased with my service to you or is there a rating issue? Please let me know if you still need assistance with this, if there is a rating issue, and/or you need more time to respond.

I like to make sure all my customers are satisfied since you did pay a deposit for me to assist you, whether I’m paid by a positive rating feedback or not.

We can continue where we left off or start over if needed. Also, if you need diagrams, instructions, etc please don’t hesitate to ask.

Expert:  Jeremy replied 4 months ago.

I removed the diagrams since there is no rating or response.

Good Day!

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