zwxetlp

Hello, I'm hoping someone can offer me some suggestions as I am having a problem that really has me stumped.

I have a 95 Accord EX that is overheating due to the cooling fan not turning on.
If I start the car and turn on the AC, neither fan comes on. While driving and after warming up, neither fan comes on. However, as soon as I turn the key to the off position and the car is warmed up, the cooling fan comes on! If I then turn the key to the Acc. position or re-start the engine, the fan will turn off. Again turning the key off will cause the fan to start again!

The fuses check out, and since the fan works when the car is off seems to indicate that the fan motor is good I've also tried swapping the fan relay with the one next to it (headlights?) since they have the same part numbers, and nothing changed.

Any suggestions? I'm really not sure where to even start with this one.

Oh, and FWIW, the radiator has developed a leak, which I would imagine is due to the car having overheated at some point, But I don't see how this could in any way be causing the symptoms mentioned above?

Thanks in advance for any suggestions.

deserthonda

yes it can and it will.... if you are very low on coolant the fans will not come on but it will come on when you shut engine off...... i would chk and fix leak, put new rad cap, new t-stat .... start car up and make sure fans work if not unplug the green plug at t-stat , jump the 2 wires together and see if fans come on if they do you got a bad fan swtich ................but first things first fix leak and fill readiator .and recheck ..

zwxetlp

Yeah, i figured that was my next step. I really hope that's it; with the prices of radiators for these things

However, I'm not sure how this could be the problem, and am inclined to think this is a symptom of the problem rather than the cause. But at this point, the price of the radiator pales into what i have invested in the car.

In theory, at least, i guess that low pressure in the cooling system may cause the fan temp sensor to be mis-reading the actual temp, but that wouldn't explain why the fan would come on when the engine was off. Unless... the engine shut off the water pump which would cause the pressure to rise in the cooling system (which we've already assumes holds no pressure) to rise setting off the temp sens, starting the fan. But then setting the key switch to Acc (NOT STARTING THE ENGINE) would then again turn the fan off?

You should now see why im kinda sceptical of dropping $150 on a new rad when I'm not sure it's the cause.

Don't get me wrong, I know the radiator needs to be replaced, It is my next step and I really hope it solves the problem, but am sceptical none the less. I can't think of anything else at this point and this is why i posted.

About the t-stat plug, even if the radiator was missing, shouldn't jumping the two contacts at the plug start the fan anyways? I'm just curious because it doesn't.

Also, could you tell me if there should be + at the fuse for the fan at all times, or only when the temp switch is tripped?

Thanks for the help,
Carl.

JimBlake

I think your year has 2 fan switches & a fan timer module. That timer module is in addition to the fan relays that you checked. The timer module (if present) is responsible for making one fan switch active when car's turned on, the other fan switch active when it's turned off. Sounds like that timer module is messed up, or bad wiring from the fan switches to the timer. Got a wiring drawing for '95? (I don't...)

deserthonda

when you jumped the connector at t-stat housing and fan did not come on you had the key on right ?? cause it won't work unless key is turned on

devilpuppy

i had teh same problem about the fan only turning on when i turned the car off

you should read this thread, it even has a picture

https://honda-tech.com/zerothread?id=1258623

zwxetlp

devilpuppy: Thanks, I was totally unaware of this second switch. I'll check that out this afternoon.

deserthonda: Yeah, I had the key on when I tried to jump the switch, but from the post referenced above I may have been jumping the wrong switch

Thanks,
Carl.

boostmyda

couldnt you just hook it up so you could manually switch the fans on?

like under the dash? then just turn them on whenever you want?

that would be sweet

zwxetlp

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ekciv901 &raquo;</TD></TR><TR><TD CLASS="quote">couldnt you just hook it up so you could manually switch the fans on?

like under the dash? then just turn them on whenever you want?

that would be sweet</TD></TR></TABLE>

Heh, I find this funny because i've actually done that on a car I had a long time ago. I thought it was cool too at the time, until the first time i forgot to flip the switch Lets just say I no longer think it's a good idea and would not recommend it

JimBlake

Check the 2 switches, one in each radiator hose nozzle. With the key on, one of them should control the fan if you jumper the wires. The other one should control the fan after shutting off, within a couple minutes. The timer is supposed to turn off the fan even if the 2nd switch is stuck closed.

If you jumper the 1st switch's wire & the fan runs, you can be pretty sure it's a bad switch. Get a new one... If you want a switch to manually turn on the fan, you can always wire it in parallel to the existing switch. That way the existing temperature switch can run the fan when you 'forget'.

boostmyda

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zwxetlp &raquo;</TD></TR><TR><TD CLASS="quote">

Heh, I find this funny because i've actually done that on a car I had a long time ago. I thought it was cool too at the time, until the first time i forgot to flip the switch Lets just say I no longer think it's a good idea and would not recommend it </TD></TR></TABLE>

ouch! that would reeealy suck

zwxetlp

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">Check the 2 switches, one in each radiator hose nozzle. With the key on, one of them should control the fan if you jumper the wires. The other one should control the fan after shutting off, within a couple minutes. The timer is supposed to turn off the fan even if the 2nd switch is stuck closed.

If you jumper the 1st switch's wire & the fan runs, you can be pretty sure it's a bad switch. Get a new one... If you want a switch to manually turn on the fan, you can always wire it in parallel to the existing switch. That way the existing temperature switch can run the fan when you 'forget'.</TD></TR></TABLE>

Thanks for the reply.
I did try a jumper on both switches. The front switch in the t'stat housing does nothing when jumpered, the rear switch on the return line to the radiator will cause the main fan to spin when jumpered. I figured this switch was the cause and replaced it, though the problem remains.

As I mentioned in my original post, my radiator does have a minor leak in it, and I will fix this next since it will have to be replaced at some point soon anyway. Im not sure how this could be the problem though; unless, it is causing air to get in the system and preventing the thermo switch from properly sensing the temp.? Possible? any other suggestions?

JimBlake

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zwxetlp &raquo;</TD></TR><TR><TD CLASS="quote">... unless, it is causing air to get in the system and preventing the thermo switch from properly sensing the temp.? Possible?</TD></TR></TABLE>Yes, that's possible.