Medium and Heavy Trucks

Have truck repair questions? Ask an Expert

Connect one-on-one with {0} who will answer your question

I have a 98 379 that the fan wont kick on after an inframe…

Customer Question
I have a 98...

I have a 98 379 that the fan wont kick on after an inframe new water pump, thermostats, new sensors. On the computer it says fan is constantly on

Mechanic's Assistant: What's the make/model/year of your truck? Engine type?

Peterbilt(###) ###-####

Mechanic's Assistant: Are you fixing your truck yourself? What have you tried so far?

Yes, I’ve put a new water pump

Submitted: 2 years ago.Category: Medium and Heavy Trucks
Show More
Show Less
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
Truck has new solenoid as well & it does nothing
Answered in 16 minutes by:
1/6/2020
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
Mike Mcmillan
Mike Mcmillan, Shop Foreman/Triage Tech
Category: Medium and Heavy Trucks
Satisfied Customers: 6,631
Experience: Volvo/Mack Master Tech, Certified with Cummins, Eaton, GM, Hino, Detroit Diesel
Verified
Hello and thank you for using Just Answer. My name is ***** ***** I will be assisting you with your question. I am sorry that you are having issues with your truck. I know this can be frustrating. I will do everything I can to help you out. Can we please start with what engine you have in your truck? Thank you
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
3406E 1LW 98 peterbilt 379
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
Were all 2 or 3 sensors replaced on the thermostat housing? Are you able to kick the fan on manually with the scan tool you are using?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
38; i can only turn it on with the dash switch. It also does turn on with the ac
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
How hot is the coolant temp getting to? The dash switch is normally wired in parallel with the thermostatic switch
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
194 is what the computer says
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
Are you getting a check engine light at all?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
now i am code 110-3
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
That fault is for coolant temp sensor open or shorted. I would examine the wiring between the sensor and the ecm. I’m sure something was disturbed during the engine work. Please let me know if you have any follow up questions on this. Thank you
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
Sensor was unplugged but fan is at 210 & still wont turn onI got it to 217 & it didn’t switch on
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
Is that fault still present? Are you able to make sure the thermistor can change state at the thermostat housing
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 2 years ago
No the fault is gone, what I’m l
Technician: Mike Mcmillan, Shop Foreman/Triage Tech replied 2 years ago
Because the thermistor on the housing is what controls the engine fan.
Ask Your Own Medium and Heavy Trucks Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a technicianLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Mike Mcmillan Your Own Question
Mike Mcmillan
Mike Mcmillan
Mike Mcmillan, Shop Foreman/Triage Tech
Category: Medium and Heavy Trucks
Satisfied Customers: 6,631
6,631 Satisfied Customers
Experience: Volvo/Mack Master Tech, Certified with Cummins, Eaton, GM, Hino, Detroit Diesel

Mike Mcmillan is online now

Related Medium and Heavy Trucks Questions
It's a 1999 Peterbilt 379 truck with a Detroit 60 series
It's a 1999 Peterbilt 379 truck with a Detroit 60 series engine. I've replaced the radiator, the water pump, the thermostats, and oil cooler and it still overheats when I'm going uphill. The fan does … read more
Nich1019
Nich1019
Diesel Technician
Vocational, Technical or Trade School
64 satisfied customers
I have a 1987 t 800 the engine fan will not kick on by
i have a 1987 t 800 the engine fan will not kick on by itself it will come on if i manually turn it on i replaced the temp coolant sensor becausr it tested bad … read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
5,115 satisfied customers
I have a peterbilt 379 with a fan that doesn't kick on with
Hello, I have a peterbilt 379 with a fan that doesn't kick on with the override switch. I just put a new solenoid on the truck and it doesn't seem to kick on when switched. I verified the voltage to t… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
6,062 satisfied customers
04 peterbilt 379 with c15. Engine fan won't come on unless I
04 peterbilt 379 with c15 . Engine fan won't come on unless I do it manually with the switch in the dash … read more
Nich1019
Nich1019
Diesel Technician
Vocational, Technical or Trade School
64 satisfied customers
I have a 5ek cat and it running 210 and gets to 220 easily
I have a 5ek cat and it running 210 and gets to 220 easily even with fan on u can't get below 210 during day fan runs all time at night long as not in hard pull will stay in 210-212 range has new radi… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
The engine fan will not come on automatically when water
The engine fan will not come on automatically when water temp gets high under a load. The fan works when I turn on manual switch and the fan works with the high pressure side of A/C. this is a C-16 en… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
Fan will not kick off. 2013 Peterbilt 389 isx cummings. And
yes and have put in a fan solenoid all new ac switches has power to solenoid when truck is not running key on but when you start it has no power to solenoid and fan wont kick out if I put power to solenoid fan shuts off … read more
Mike Mcmillan
Mike Mcmillan
Shop Foreman/Triage Tech
Associates
6,631 satisfied customers
2001 379 pete. Fan runs constantly and kicks off and
2001 379 pete. Fan runs constantly and kicks off and immediately back on sometimes. It takes power to disengage fan...when I ran a bypass from battery to fan toggle it could manually operate it to sav… read more
Mike Mcmillan
Mike Mcmillan
Shop Foreman/Triage Tech
Associates
6,631 satisfied customers
I have a 98 379 that the fan wont kick on after an inframe
I have a 98 379 that the fan wont kick on after an inframe new water pump, thermostats, new sensors. On the computer it says fan is constantly on … read more
james Roberts
james Roberts
Maintenance assistant
Vocational, Technical or Trade School
3 satisfied customers
I have a CAT C12 and the Fan doesn't turn on automatically
I have a CAT C12 and the Fan doesn't turn on automatically only when I turn it on manually. However it does turn on automatically when the AC is on … read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
My engine fan will not turn on. Either with the manual
My engine fan will not turn on. Either with the manual switch or just letting the ecm do it by water temp. I've replaced the fan air solenoid and it still will not engage. Unless I cut the wires to th… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
2002 379 pete c15 6nz cat .engine will not start without
2002 379 pete c15 6nz cat .engine will not start without either . has new fuel pump new injectors new cam and crank sensors new engine wiring harness new check valves new filter housing, new ecm. Has … read more
Edward Haniewski
Edward Haniewski
General Studies/Automotive
1 satisfied customers
The engine temp runs up to 212 degrees and fan isn't coming
The engine temp runs up to 212 degrees and fan isn't coming on. I replaced the fan trigger on the thermostat housing and checked the thermostats. I have a 170 and a 180 degree thermostats on it and th… read more
PATRICK WENSLEY
PATRICK WENSLEY
Associates Degree Of Applied Science
98 PETERBILT, the speedometer works but shows no speed on
98 PETERBILT, the speedometer works but shows no speed on the computer, cruise does not set. … read more
Andy
Andy
truck /coach technician
Vocational, Technical or Trade School
214 satisfied customers
Speedometer doesn't work only works part of time but doesn't
Speedometer doesn't work only works part of time but doesn't read right I think short wire … read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
What style plug is the connector for diagnostics on a 1992
what style plug is the connector for diagnostics on a 1992 peterbilt with a detriot engine??. i believe ddec 2... its a rectangle plug not a round plug like newer trucks... i need to see what its call… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
6,062 satisfied customers
2004 Peterbilt 379 w/C15 acert fan will not turn on with
2004 Peterbilt 379 w/C15 acert fan will not turn on with switch in "auto". Gets up to 225-230 with no warning light or buzzer. It just started doing this about a week ago. Prior to that it kicked on a… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
2000 peterbilt379 AC stopped working. Had to straight wire
2000 peterbilt 379 AC stopped working. Had to straight wire to get to cool I got power at AC fuse but the compressors not coming on. When it builds head pressure the fan kicks on with it straight wire… read more
Jim
Jim
Diesel tech.
212 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Daniel Wilson

Daniel Wilson

6,062 satisfied customers

Owner at DJ Wilson

Cat Man

Cat Man

Cat Engine Expert

5,353 satisfied customers

I am ASE Master Truck Certified.

Wayne

Wayne

Journeyman

5,115 satisfied customers

worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling

Jeremy

Jeremy

Certified Truck/Bus Technician

2,756 satisfied customers

ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, Network Engineer specializing in CAN faults, Aftertertreatment, and vehicle communications

Curtis B.

Curtis B.

Technician

1,947 satisfied customers

Technician turned service manager on multiple lines of trucks and engines, used in industry.

cumminsdr

cumminsdr

Mechanic

1,886 satisfied customers

All types of Cummins applications

Chris (aka-Moose)

Chris (aka-Moose)

Technician

641 satisfied customers

24 years of experience diagnosing & repairing

< Previous | Next >

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x