caliskier

I just bought a 91 accord, and I am having a bizzar problem. It is a 1991 Accord with 4-cylinder 16 valve engine. I take it for a short drive and the temperature gage reads normal however the radiator boils over as soon as I stop. Does not seem to be a problem when I am driving. When I stop and shut off the car I am unable to restart it until it rests for a bit. A/C cooling Fan on left turns on with the A/C and after the car warms up. Cooling fan on the right does not come on at all. Are there two separate thermostatic fan switches for the fans or are they controlled by one switch? Don't know if the fans are the problem. Odd that the temperature gage comes up to and stays at 45% and my radiator boils over. I would think the gage would be all the way to hot if it is boiling over.

By the way, where is the waterpump on these things my 87 had the pump on the right with the a/c and power stearing? Also, the thermostat, on the 87 it was in the return line on the back of the engine, but it looks like that line is water to the engine, can you tell me what line the thermostat is on?

Thanks for any advice.

ujhonda

If you want to solve this problem for good, don't use shot cut...

pressure test your cooling system - see if you find any leaks fix it right there. then replace your thermostat and check your radiator fan and its switch.

don't drive till you fix all those...

bseriescrxsi

i would replace both the temp fan switches and the thermostat......follow the radiator lines to find each of the 2 fan stitches and the thermostat is on the engine end of the bottom radiator hose...this should fix your problem.....don't let it go as is and don't take short cuts...you can badly damage the head

caliskier

Really, the thermostat is on the hose that comes from the bottom of the radiator? So the thermostat is on the back hose, not the one that comes from the front? Looks like there is a thermostatic switch at both of the points where the radiator hoses connect to the engine. Are those the fan switches? Thanks for your help on this.

caliskier

Really, the thermostat is on the hose that comes from the bottom of the radiator? So the thermostat is on the back hose, not the one that comes from the front? Looks like there is a thermostatic switch at both of the points where the radiator hoses connect to the engine. Are those the fan switches? Thanks for your help on this.

tech8

The thermostat is under the thermostat housing on the engine side, of the bottom radiator hose. The thermoswitch which turns the radiator fan, when the engine is <U>on</U>, is also at that location. Either this thermoswitch is faulty, or your radiator fan motor or wire is faulty.

Here is a link:

http://techauto.bravehost.com/

The other fan switch on the other housing, is to turn the radiator fan on, when the engine is <U>off</U>. It is also shown in the link.


Modified by tech8 at 9:28 PM 8/9/2007

caliskier

Ok, I found both thermoswitches, one next to the engine where the hose starts to go to the bottom of the radiator and the other where the hose goes back from the top of the radiator to the engine, this one is next to where the hose connects to the front of the engine. Applying a jumper wire to either of the green plugs will power on the cooling fan on the left side. The fan on the right has never powered on with any jumper wire. The question is, do these switches power both fans? The left one turns on for everything including A/C. The right one never comes on. Is there another thermoswitch hidden somewhere that powers the right fan?

bseriescrxsi

im not sure of the order so dont hold me to it 100% but i believe this is what they are(standing in front of the car looking at it) A/c Fan is on the right radiator on the left.....pull the radiator up and look for any diverted wiring that someone may have run

and as for the whole overheating while still and normal while moving....when moving the air is being forced into the radiator and it kools itself(on a mildly hot day your screwed either way) and when you come to a standstill no air is going through it

caliskier

The Fan on the left is for the A/C, I know that because it comes on when the A/C comes on. What I am wondering is, do both the thermoswiches on the top of the engine power both fans. I know that both swiches power the left one, but am wondering if they are supposed to power the right one as well. A guess the real question is, assuming the right fan is working, where is it's thermoswitch that I need to short to make it come on?

ddg2sailor

It dosent really sound like a thermostat problem. I dont like short cuts but a good way to test the switchs is to short em.... but dont get me wrong this isnt a fix its just diagnostic.

Robert

caliskier

What I am wondering is, do both the thermoswiches on the top of the engine power both fans. I know that both swiches power the left one, but am wondering if they are supposed to power the right one as well. A guess the real question is, assuming the right fan is working, where is it's thermoswitch that I need to short to make it come on?

I do not think it is a thermostat problem either, it is a fan problem, and the problem is the right fan won't come on. I need to know where the thermoswitch is for this fan so I can determine if it is the switch or the fan.

tech8

Standing in front of the car, the radiator fan is on the left, and the A/C condenser fan is on the right.

1. Sounds like the radiator fan works. Does this fan come on when the car is fully warmed up and idling (don't turn on A/C)? If not, it could be the radiator fan relay or the thermoswitch on the thermostat housing.

2. Doesn't sound like the A/C condenser fan comes on. Check the fuses first, on your 4th gen Accord, check the No. 2 (15A), No. 29 (15A), No. 7 (7.5A) , and No. 8 (7.5A) fuses. To test the motor, you can apply battery power via a jumper (a fused jumper is better) to the motor wire connector. Just follow the wires to the plug coming directly off the motor. If the motor works, then it could be the A/C condenser fan relay, or wiring, etc.

caliskier

Thank you, appreciate the details. I will have to check it again, but I am almost 100% sure that the left one (standing in front of the car) came on when we turned on the A/C for a second, and I am sure that same one came on when the car heated up. The right one never turned on. I am thinking that the left one is for the A/C, I will have to look at that again. Can't at the moment as it is at a friends house.

Don't know if this little detail matters, but the left one is a 5 blade fan and the right one is a 4 blade fan

tech8

Standing in front of the car, the left should be the radiator fan. Here is a pic. of my 5th gen. Accord, slightly different; but, still alot of similarities. Your A/C condenser fan relay, and A/C clutch relay are different though.

caliskier

Wow, you took pictures, thanks very much. I will have to go out to the car again and turn on the AC to see which one comes on to be sure, but I thought when we were messing with it the other day, the one you point at as the radiator fan comes on with the AC and with heat, and with jumper wires to either green plugs that go to the thermoswitches. The one you are calling the A/C fan never comes on. Going to check again though, thanks again.

By the way the green plug 6:00 from your radiator fan text box is one of the thermoswitches that I got the fan on the left to run on.

...will have to check it again.

Very helpful thanks.

tsiah

both fans should run with the AC turned on.

I suspect a problem with the radiator fan itself or the wiring to it.

if you have and know how to use a DMM, unplug the radiator fan, start the engine and switch on the AC. measure voltage at the 2 pins on the rad fan connector. if you have 12-14 volts there, the problem lies with the fan motor itself. if you dont, the problem lies in the wiring, a fuse or the relay for the cooling fan.

I would get the cooling fan issue fixed, replace the radiator cap, change the coolant (make sure you use a 50/50 mix) and thermostat.

edit: you say the condenser fan isnt running...everything I said about the radiator fan applies

caliskier

Wow, you took pictures, thanks very much. I will have to go out to the car again and turn on the AC to see which one comes on to be sure, but I thought when we were messing with it the other day, the one you point at as the radiator fan comes on with the AC and with heat, and with jumper wires to either green plugs that go to the thermoswitches. The one you are calling the A/C fan never comes on. Going to check again though, thanks again.

By the way the green plug 6:00 from your radiator fan text box is one of the thermoswitches that I got the fan on the left to run on.

...will have to check it again.

Very helpful thanks.

caliskier

Tech8 you have been very helpful. I tried to jump the fan by putting power to the fan via a jumper. Did not have a fuse though. Does it matter which side you apply the jumper + - ? was not sure. I had the fan disconnected except for the wires that looked like ground wires for the case toward the bottom of the fan. When I tried to jump it, I thought I heard a soft thud/click. But no spark from me touching the connectors with the wires. Maybe I did not have the wires connected well enough to the battery, I just taped them on to the terminals with a piece of electrical tape. Does this tell me my fan is bad or that I didn't do the procedure correctly.

tech8

Looking at the fan plug, with the lock tab on top, positive to left terminal and ground to right terminal.

If the fan motor does not run or does not run well, then the motor should be replaced.

caliskier

Yeah, it is definitly not the motor, replaced the motor and the new one does not work either, worked at the junkyard, they tested it for me. So what we have is the radiator fan works, but the a/c fan on the right is not getting power. I have a prelude and both fans come on when the a/c turns on. The A/C fan did not turn on. So it must be a wireing issue. Any suggestions?


Modified by caliskier at 1:24 PM 8/19/2007

caliskier

reading back through the string of posts...I did not check a/c fuse, just radiator fuses...if that is the problem...great, but so much frustration.

caliskier

Ok, checked all fuses, 2, 7, 8, and I think 29, all fine. Under the hood there was a 15A labled cooling fan over on the right second from the right in the back. This is a real bugger of a problem.

tsiah

have you checked the fan relays?

I dont see any posts that have answered this...your water pump is driven by the timing belt. its under the timing belt covers.

caliskier

Yes the water pump, thanks, someone at oriley told me that. Fan relays? There is a radiator fan relay, but the radiator fan works, is there an condensor fan relay?

tech8

There is a condenser fan relay. Look in the picture I posted above. On your 4th generation, I think they look like cylinders instead of the boxes like the 5th gen. Also, they may be located a little differently. Look for two cylinder like objects, one is the A/C condenser fan relay, the other is the A/C compressor clutch relay.

On your 4th gen, the condenser fan relay should be located near the front driver side fender.


Modified by tech8 at 3:18 PM 8/19/2007