here's the deal:

91 accord auto. this year, the gauge goes up halfway, and when sitting in traffic, will start to steadily move up about half the distance between half and the top. at that point, BOTH fans will kick on, and it'll bring the temp down to the halfway again. in a couple more minutes, it starts heating up again.

the gauge used to be rock solid. now it is my understanding that there are two temp switches for the fans. it is also my understanding that the cooling fan will come on independent of the a/c in order to keep the car at the proper temp (and make that gauge stay rock solid). my fans will NOT work independently. when i turn on the a/c, they both stay on, and the temp is more or less fine (still halfway up, which is higher than it used to be)

there is a fan switch on the tstat housing on the back of the motor. i don't know whether this is fan switch A or B. i jumped it with the motor off and both fans kicked on, so i replaced it with a new one. no change.

is there a secondary fan switch that i need to check out?

could this all be a thermostat thing? (doesn't seem likely since i never get the cooling fan to come on by itself)

if the fan relays or fuses were bad on either fan, wouldn't both fans be dead all the time?

thnx guys

 

thats wierd, cuz i have the same generation accord as you and when i put my a/c on, only the passneger's side comes on...and im pretty sure that is the only side that kicks on when it is forced to. maybe my driver's side one is broken?

i would try a thermostat and possibly a coolant flush considering both should be under 20 bucks.

 

thermostats are mech only pieces though, and my car gets hot enough that both fans kick on later (at the ~212deg or so that makes them both kick on), but the first fan never kicks on to try to knock the temp down while its heating up.

 

but isnt it supposed to kcik on at 180?

 

I had the same problem on mine. The temp sending unit went bad, I replaced it with a non-honda senind unit, and then it did the same thing. I think the calibration was not correct.

I eventually replaced with a honda sending unit with no problems.

The switch A controls when the fans kick on when running. Switch b is for when the car turns off and the engine continues to warm up. It will kick on when everthing has been turned off.

Switch A could be bad too, or the thermostat could be sticking.

when I went through this, I replaced the thermostat, switch a and b. All because of a sending unit and a non-honda part. I only use honda parts now. They really are better.

 

ok, i first need to know which sensor is temp switch A, and which is B.

as far as i know, the tstat starts opening a bit before 180, and is fully open by 180. the cooling fan is supposed to come on around 180. the second one kicks in at ~212deg to make sure the car doesn't over heat.

the 212deg dual fan turn on is the only one that works on my car automatically

 

Switch A is near the thermostat. Switch b is closer to the front of the car and kicks on at a higher temp, when not running. Temp builds up to 212 after the car is off the switch will close the circuit. It is a higher temp due to latent heat after the engine is off and no more cooling going on via cooling system.

The switch A kicks on, I blieve around 192 or 196 and is set to kick on when the thermostat is fully open, but not keeping the temp down due to lack air movement ie when idling and stuck in traffic.

Interestingly, the honda sending unit and gauge do not show any difference in this small temp change.

Do your fans kick on when the ac turns on? The AC system should override the whole system and start the fans to cool the AC radiator.

How high will the temp eventually get to?

When does the overheating occur? What have you checked already? Will the fans ever kick on? Oh and btw, I think the switch b only turns on one fan, but you would need to check a manual.

 

I suggest you change the sending unit. My sending unit went bad and the gauge showed all kinds of strange things. I had this same problem when I put in a non honda sending unit. Should be around $25, and while you are at it change the thermostat. It never hurts to have a good thermostat in the car.

 

both fans will turn on with the a/c. the gauge will go as high as the top of the N of neutral (i use the PRNDD21 list as a reference for needle position). both fans will kick on and it goes back down to half way or a bit less.

i changed the sensor near the thermostat (the lower rad hose attaches to that one), and it made no change to the fact that the cooling fan will not come on itself.

the fans WILL come on when the car is off if the temp is high enough to cool itself back down.

i guess i will try a new sending unit...even though i hate throwing a lot of money for high priced honda parts on a car that only cost me 1500

thnx for the help guys! i'll keep you posted on the results

 

well, i figure'd out my cooling fan woes...this morning i went to go look at it again. the cooling fan was UNPLUGGED!

i plugged that bitch up, turn the car to II and put on the A/C and both fans turned on.

so remember to check your connections guys!