cooling fan doesnt turn on (tried almost everything)
#1
cooling fan doesnt turn on (tried almost everything)
Ok so i did a mini-me swap on my girlfriends 98 civic but the cooling fans will no come on. If i turn on the A/C the A/C fan kicks on but not the radiator fan. If i unplug the coolant temperature switch and jump the wires the fan kicks on. The coolant temperature switch is one on three new ones that i bought. I swapped out the fan relay with the other relay that is in there as well. New fuse as well.
So correct me if im wrong but all i can conclude from this is the ECU is screwed up.
Any ideas? what temperature should the fan kick on?
So correct me if im wrong but all i can conclude from this is the ECU is screwed up.
Any ideas? what temperature should the fan kick on?
#2
Honda-Tech Member
Re: cooling fan doesnt turn on (tried almost everything)
Try changing the coolant temp sensor or make sure that the plug is on there snug. (this is not the coolant temp switch IT IS DIFFERENT)
#3
Re: cooling fan doesnt turn on (tried almost everything)
The ECU has nothing to do with the radiator fan. Try bleeding the cooling system.
Bleeding the cooling system may take 20-30 minutes.
1) Park the car on an inclined driveway with the front end higher than the rear.
2) Push/turn the dash heater lever/**** to MAX heat. Fan need not be on.
3) Follow the directions in the diagram below
Bleeding the cooling system may take 20-30 minutes.
1) Park the car on an inclined driveway with the front end higher than the rear.
2) Push/turn the dash heater lever/**** to MAX heat. Fan need not be on.
3) Follow the directions in the diagram below
#4
Re: cooling fan doesnt turn on (tried almost everything)
Coolant temp sensor is brand new and working according to my obd2 scanner.
I did the bleeding procedure for about 45 min and the temp on my scanner kept going from 189-191 but not any higher and it was 85* out today.
Not sure why it wouldn't get any hotter but if i drive it for awhile it will start boiling coolant out of the overflow because the fan never turned on. This only happens if i drive for more than 30 min or so.
Any other ideas? Thanks for the help guys
I did the bleeding procedure for about 45 min and the temp on my scanner kept going from 189-191 but not any higher and it was 85* out today.
Not sure why it wouldn't get any hotter but if i drive it for awhile it will start boiling coolant out of the overflow because the fan never turned on. This only happens if i drive for more than 30 min or so.
Any other ideas? Thanks for the help guys
#5
Re: cooling fan doesnt turn on (tried almost everything)
You may have a blown head gasket that is blowing exhaust gas into the cooling system. The gas pocket may prevent coolant from registering the correct temp at the switch and sensor. There's a kit available for measuring exhaust gas in the coolant.
#6
Re: cooling fan doesnt turn on (tried almost everything)
I shure hope not since i just got the engine back together after rebuilding it. I had the head and the deck machined and used a honda head gasket. I dont see any air bubbles like i did before i rebuilt it.
#7
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Re: cooling fan doesnt turn on (tried almost everything)
you could test the rad fan switch by putting it in boiling water an check for continuity across the posts
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#8
#9
Re: cooling fan doesnt turn on (tried almost everything)
Right... The coolant temp sensor tells the ecu what temperature the coolant is where the coolant temp switch closes contacts at a certain temperature to turn on the fan.
Does anyone have a wiring diagram of the cooling fan system?
Thanks
Does anyone have a wiring diagram of the cooling fan system?
Thanks
#13
Re: cooling fan doesnt turn on (tried almost everything)
Yes, but in this case, the A/C wouldn't work. If you can jump the 2P fan switch connector and the radiator fan runs with the key in ON(II), then the fan circuit and fuse is fine.
#14
Re: cooling fan doesnt turn on (tried almost everything)
Does the temp gauge go past 1/2? The fan will not come on unless it goes slightly past 1/2 way up?
Since you did a swap, did you put in the proper thermstat? That can affect when the fan will kick on as well.
Since you did a swap, did you put in the proper thermstat? That can affect when the fan will kick on as well.
#15
#16
#17
Re: cooling fan doesnt turn on (tried almost everything)
In general, the normal temp position for our Civics is about 1/3 or just slightly higher, not halfway. Can't say why yours reads higher. Using a scan tool, what is the range of your coolant temps from the ECT sensor at normal operating temp?
#18
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Re: cooling fan doesnt turn on (tried almost everything)
make sure if you got an aftermarket coolant fan switch that the connector snaps into it. i got a fan switch from autozone and it doesnt fit well at all. you can back probe the connector at the switch and see if you get continuity when it warms up.
#19
Re: cooling fan doesnt turn on (tried almost everything)
Also, we have to take into account these gauges are just visual guidelines, and never 100% accurate.
#20
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Re: cooling fan doesnt turn on (tried almost everything)
very true my buddies eg has always sat lower than half way but my ek has always sat dead in the middle.
#21
Re: cooling fan doesnt turn on (tried almost everything)
I would be concerned by a halfway reading.
#22
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Re: cooling fan doesnt turn on (tried almost everything)
i have been driving my car for four years no problems halfway reading...
#24
Re: cooling fan doesnt turn on (tried almost everything)
So by looking at the wiring diagram, if you jump the coolant temp switch connector and the fan comes on then everything in the circuit is working properly and either the switch is bad or the car is not warming up enough to close the contacts on the switch or there is a bad connection between the switch and connector.
Any other ideas?
Thanks guys for the help
Any other ideas?
Thanks guys for the help