I have a 93 Accord with about 165K on the clock. I got it last fall and between work and the cold weather I have put off working on it until now. I have verified that the coolant level is where it should be and the air is bled from the system. I started it today and let it idle until it came up to temperature, about 5 minutes. While warming up, I noticed the upper radiator hose got warm but the lower only had a few warm spots on it. The temperature gauge was nearing H. I then brought the RPM's up to about 1500 for 30 seconds and the temperature dropped back to the middle of the gauge. Again, idling for a couple of minutes the gauge had climbed up to near the H again. After this second time letting the temperature climb, I checked the lower hose and it was hot just like the upper. It also seemed the the upper hose had a lot of pressure in it, it was hard to even squeeze it a little.

Now, neither of the fans are running during this time. They both work (verified with jumper wires) and all fuses are good. Is it possible that both relays crapped out or is it one (or both) of the sensors (switches)?

What I am wondering is if this is a flow issue or if it is only getting so warm because the fans aren't running.

 

It sounds like you may have two problems.

With on hose being colder than the other and the gauge going to H, I would replace the thermostat with one from a honda dealership. I would replace the coolant at the same time.

When the car is cold, start the engine and turn on the a/c. See if both fans turn on. If both fans run, I would jump the connector to temperature switch A on the thermostat housing. Both fans should turn on. If both fans turn on, I would replace that thermoswitch while doing the thermostat change.

 

OK, I can replace the thermostat , I have one here for it. The coolant is less than a year old, it was replaced right before I got the car.

I did that already, started the car and turned on A/C, neither fan runs. My next step will be to test continuity of fan switch "A" while the car is warming up.

 

If fans don't turn on w/ AC and jumping thermoswitch A, you either have bad fans (possible) or both fan relays are open.

Could be either, but most likely is the fans are dead, people don't notice whether the fans go out until there's an overheating problem. The car will never overheat while moving, so unless you idle at stop frequently, you could go a long time w/o observing the problem. Note, your ac performance at idle will be terrible and can cause excess ac system pressures. AC will perform OK at speed.

good luck

 

the cooling fan relay is in under hood fuse box. also check the fuses. there are two in underhood fuse box that could cause cooling fan problem. the cooling fan is the one on the passenger side. The A/C condesor fan relay is located just behind the power steering pump on inside of fender. It has three parts.starting from front of car the first relay is a/c clutch relay, then there is a smaller black diode. then the third one is the condenser fan relay. the condenser fan is the one on drivers side. Also in car fuse box has three fuses that need to be good in order for all fans to work normal. I dont remember which fuses, just that there are 3 in under dash and 2 in under hood. May not be related to your problem but good to know.

 

I verified that both fans run by unplugging them and using jumper wired to the battery. Both fans run with 12 volts to them.

I checked all the fuses(underhood), they are all good. I will check all the in car fuses next. I may need to test the relays though, any advise on how to do that?

Thanks for the info on the location of the condenser fan relay, all my book says in the left front of the engine compartment

 

A quicker way to test the relays is to start the car. Turn on the a/c and see if both fans are running.

 

just switch the relays with each other . they are the same

 

We are assuming the ac works? When you turn on the ac, does the ac comp clutch engage?

Did you jump thermo A (on t-stat) while the car is running and the fans did or did not come on, not 100% clear as I read it...but I can't read very well.

"My next step will be to test continuity of fan switch "A" while the car is warming up. "

 

If the switch for the A/C is the one below the recirculate button on the HVAC controls(the cover on the switch is missing but it lights up when pushed), then no the A/C clutch doesn't seem to be engaging when the button is pushed.

I just jumped switch "A" tonight (with key in run position) and both fans run. I found this easier to do than testing the continuity of the switch itself, which is really hard to get to. Placed a short section of wire in both terminals of the plug and turned the key on.

So, it would appear that switch "A" is faulty and the relays are good.