Am thinking i have a bad thermostat but wanted some feedback from the experienced minds here.

The car: a beater '88 Accord LX, manual, 266k miles. i try to put as little as possible into it to keep it running and to get it thru DEQ when needed.

Twice in my last 4 drives of this thing, I have noticed that when I have the front defrost on, and the heat set to high, that nothing but cold air comes out. I look at the temp gauge and it is shooting up to high. Fortunately, in both cases, i was close to my destination and made it.

The other two drives of the last four were returning home from the above 'cold air' trips. But in each case, i turned the blower on high BEFORE starting the car (or just as I started it), and everything was fine --warm/hot air coming out of the defrost, temp gauge stays in the normal range, no issues.

At first I thought I had a one time stuck thermostat. But now that is has occurred twice am thinking I need to replace the thermostat. I replaced the thermostat about a year and a half ago or so.

Agreement on approach, or other ideas?

thanks!

 

Does the temperature start rising when you are driving, or at a stopped?

When the engine is cold, remove the radiator cap and check that the fluid is filled to the top. If not, then top it off, and then you will have to find out how/where you are losing coolant.

Also, start the engine and turn on the a/c. Do both fans on the radiator turn on?

Inspect the radiator for any debris that may block air flow. The radiator is behind the a/c condenser, so you might not be able to easily see the front of the radiator. You can clean the fins by using a garden hose on it (no nozzle, because that will bend the fins).

If you decide to replace the thermostat, I would buy one from the Honda dealership.

 

No love for the 3rd gens...

 

Poorman - I have a lot of love for the beater, which i refer to it lovingly. That thing just keeps going and going and going. I absolutely love its reliability. But it is a beater -- oxidized everywhere, tons of things nor working, a variety of leaks. it is on its last legs, has been for sometime, I just don't know yet what I can afford to switch to, and figure with a little fix here and there I ccan keep this puttering along until i can figure that out.

 

PAHonda - good question on when does it start rising. thinking back over the 2 trips where it increased, one was when i was stopped i believe, and the other was when I was driving. However, on the second one, i noticed it rising when i was stuck in a line of traffic and slowly moving. what would that suggest? A fan issue? And foolishly enough I have not checked the rad fluid level yet. i made the assumption, since i haven't seen any green liquid dripping, that the rad wasn't the issue. But I will check that definitely, along with any fin blockage, tho i doubt that is the issue.

I replaced the radiator a couple years back (when I replaced the thermostat). Please provide a little more background on the fans. What is the issue if one or the other doesn't turn on? Is it the motor that then needs replacement? or something else?

Any theories on why it has happened to work when i start the blower before or when i start the car? just a coincidence or ....?

thank you.

 

Yea, the dang 3rd gens just seem to go and go.....and I was just joking around

Check the fluid level and if it is low, need to figure out where it is going.

If the coolant level is fine. You want to be sure both fans run when the car is running. You can put 12v directly to the motor(s) and be sure they spin. The temp switch for the fans is in the lower right/pass side of the rad.....you should have moved that from your old rad to the new one when you did the install.

 

how do i put 12v directly to each of the fans?

 

Find the two wire connector(s), run a piece of wire from the battery post (+) to one side if the connector then add a ground to the other. I think the connector for the right/pass side you have to get to from under the car....so that damn plastic tray has to come off.

Or..........pull the connector off of the thermo sensor on the bottom of the rad. Use a paper clip and jump the terminals on the wire side of the connector and turn the key to "on"/pos II.....both fans should run.

If only one runs, let us know which one (drivers or pass side). There are relays and fuses that could prevent to motor from running.

 

thanks for the diagram. I have done this before and realized it involved a paper clip, but forgot process. i don't know what you mean by running a ground to the other side of the connector. What i am beginning to remember is that I need to unhook the switch from the connecting wire. Then I put a paper clip in one side of the switch that is connected to the fan. Then I run a piece of covered wire (copper?) from the endd of the paper clip and touch the + side of the battery, right? If the fan spins, the switch is good. If not, the switch is bad. Is that all accurate?

So I just went out and collected a little more info:
1. Rad fluid seems fine. Not to the very top, but visible about and inch or so down. Rad still looks in excellent sshape from when I replaced a couple yrs or so back. And I have seen no evidence of a leak.
2. I turned the car on - neither fan spun. But it has been sitting all night, so I shoouldn't expect that until the car is warmed up, right?
3. I turned the blower on high and turned on the AC as suggested above. Again, neither fan spun. The AC fan is the one on the pass side?
4. I checked the main fuse box under the hood, where as you know there are a few fuses associated with fans - one or two main ones then a sub-cooling switch (or maybe fan) fuse. How can I tell if they are OK? The top of all look the same. The fan ones seem to be larger than the others and have a plastic top on them. Can I just pull them out with pliers?

thanks for your continued help.

 

The thermo switch in the bottom of the rad "closes" to ground when at temp. This sends the ground sig to the relay. So "jump" the two female pins going to the thermo switch with a paper clip. Turn the key to on/pos II - does not have to be running just the key to on like it would be if the engine was running.

Does the AC work...meaning does the ac compressor come on and cold air coming out of the vents.