HELP! Rad Fan Off When Ignition On...Boiling

[lokuputha]

Hey guys, I need some serious help...i've tried to diagnose this but im coming up with nothing....

Problem: Radiator fan is off when ignition is on, and only turns on when I turn the ignition off.

Symptoms: boiling during driving

Solution:___________________________________________...fill in the blank?


takes:

-fan temp sensor/switch (replaced....problem still exists)
-fuses (all are good)
-relay (switched relays....problem still exists)

Thanks in advance

[lokuputha]

peanut butter and ham sandwiches

[jhondayaaj]

obviously your car is running hot because your cooling fans are not coming on when they are supposed to. I would suggest you replace your thermostat and your thermo switch to start. the switch is on the thermostat housing. good luck.

[accordaffair]

http://media.honda.co.uk/car/owner/m...400/16-103.pdf

How about the timer unit/radiator fan control module?
http://media.honda.co.uk/car/owner/m.../400/15-62.pdf (few pages in, cooling fan timer unit input tests)

also see
http://media.honda.co.uk/car/owner/m.../400/15-48.pdf

let me know

[lokuputha]

http://media.honda.co.uk/car/owner/m...400/16-103.pdf

How about the timer unit/radiator fan control module?
http://media.honda.co.uk/car/owner/m.../400/15-62.pdf (few pages in, cooling fan timer unit input tests)

also see
http://media.honda.co.uk/car/owner/m.../400/15-48.pdf

let me know

accordaffair u r the man, man!...thanks for the links...im going to do some diagnosing....i have a feeling its the Fan Control Module too...

Thanks

[jhondayaaj]

good luck and keep us posted.

[lokuputha]

obviously your car is running hot because your cooling fans are not coming on when they are supposed to. I would suggest you replace your thermostat and your thermo switch to start. the switch is on the thermostat housing. good luck.

replaced the thermo fan switch....got a new thermostat last year...so im still thinking its the Fan Control Module...

...the only problem is the module costs $207.00 ....thats a lot...even in terms of Canadian currency

[SMseagren83]

hmm just by reading it would have thought it was the thermo switch A. that one is supposed to send signal when temp rises to 180 (when car running) to turn on cooling fans. and the thermo switch B sends signal when ur car is off and temps rise to 260 degrees. switch A in on thermostat and switch B is on the front water neck.

thats strange.....arent both fans supposed to turn on? im not 100% sure about that. have you tested the cooling fan motor??? hook jumpers directly to the battery and see if it turns on, if it does and u already placed the switch and fuses are good. its the timer module.

best of luck.

[nucleara]

the one fan I think only turns on when ac is on.

[oranger]

the one fan I think only turns on when ac is on.

thats true. the A/c fan is the one on the drivers side and the regular cooling fan is the one on the left. Never heard of the timer module failing, but then again, my harmonic balancer just broke, so weird things can happen.

[lokuputha]

spoke with the mechanic today, and he said he fixed a bunch of swapped accords lately with the exact same problem...

symptoms:
-temp switch A (beside the thermostat) is not turning on
-upper rad hose very hot while lower rad hose is cold
-interior of car heats up
-rad fans will only turn on once ignition is off
-coolant overheats even when rad fans are hot wired and run all the time

cause:
rusted water pump

description:
swapped motors are usually left without coolant and exposed to water for prolonged periods of time... The fan vanes, which are steel, will usually rust away.

why now:
4000rpm for 1000km would cause already rusted and weakened pump vanes to deteriorate eventually leaving almost no vanes to pump the coolant.

[accordaffair]

so the fans were running?

[SMseagren83]

was that a honda tech? i would not say its the water pump based on YOUR symptoms and description in the original post.

[lokuputha]

so the fans were running?

the fans were working but they would not turn on b/c the temp switch near the thermostat wasn't getting any fluid...

the lower coolant line is cold while the top one is very hot.

was that a Honda tech? i would not say its the water pump based on YOUR symptoms and description in the original post.

yes he is, he actually fixed two different engine-swapped Accords with the same problem in the last month.

[jhondayaaj]

spoke with the mechanic today, and he said he fixed a bunch of swapped accords lately with the exact same problem...

symptoms:
-temp switch A (beside the thermostat) is not turning on
-upper rad hose very hot while lower rad hose is cold
-interior of car heats up
-rad fans will only turn on once ignition is off
-coolant overheats even when rad fans are hot wired and run all the time

cause:
rusted water pump

description:
swapped motors are usually left without coolant and exposed to water for prolonged periods of time... The fan vanes, which are steel, will usually rust away.

why now:
4000rpm for 1000km would cause already rusted and weakened pump vanes to deteriorate eventually leaving almost no vanes to pump the coolant.

dude, you need a thermostat then. upper hose hot and lower hose cald means t stat not operating as it should. replace the thermostat man. And I am no kid off the street. I work on cars 5 days a week and if I saw this symptom on a car, I would definitely replace the thermostat to start.