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I have a 97 Accord LX. I have no heat, the cooling fan does not come on when the engine is running, but does when the car has been running for a while and then is shut off. The a/c works perfectly--both fans come on. I replaced the thermostat and the sensor on the thermostat housing--both to no avail. Can't be the fuses or relays--both fans come on when a/c is on. Pulled sensor on thermo housing and jumped wires, and the fan came on. Did the same on the sensor near the upper hose--fan came on, so not a wiring problem. I'd appreciate any help.
sso is there no heat or the blower motor does not blow?
^ WOW, someone found their way out of GDD....what is going to happen to "tech" now
OP - need to check that the heater control valve cable is moving when you turn the **** from heat to cool and back.
Next check the temp of the hoses on both side of the valve when open (heat) and be sure the valve is opening.....they can fail internally which meands the cable moves and you think it is opening but it is not. If both hoses on the valve are getting hot also check the return to check if there might be a blockage in the heater core.
Checked both control valves--the one under the glove box and the one at the firewall. Both open and close. Just replaced the sensor near the radiator. Fan still does not come on, car still overheating, fan still coming on when engine is off, but now the engine is surging intermittently. Don't know what else to try.
Thanks for the reply. Changed the thermostat again, bled the coolant again, jumped the switch at thermostat and the switch at the end of the top radiator hose, and both made the fan run. The top hose gets hot, and the bottom one gets warm. Car gets to operating temperature in good time. Still no heat. Cooling fan came on once, then not again, and car started to overheat. I'm going to test the thermistor at the thermostat to see if that's why the fan doesn't run, But I'm mystified about still getting no heat. Maybe a blocked core?
Lets solve the overheating before we get into the heater core.
Next, might just be the wording - BOTH cooling fans should run when needed and the key is in the "on" position. So with the key on, just the wire connector to the cooling fan switch on the t-stat housing where the lower hose connects. Do BOTH cooling fans come on?
It sounds like your fan switch is not working. Replace with a fan switch A from a Honda dealer. Don't buy aftermarket as they are junk and don't last even close to as long. The fan switch is the one that goes where the lower radiator hose goes to.
For the no heat, it could be that your thermostat is stuck open. The lower hose should get as hot as the upper hose after the car has warmed up. If not, then you need a Honda thermostat as well.
Thanks for the suggestion. I just put a Honda thermostat in, so I guessing the heat problem lies elsewhere. I am going to take the fan with out and test it in hot water to see if the resistance drops. I'm actually hoping it doesn't so at least I will have solved part of the problem.
Almost sounds like you have air in the system. But if you've bled properly, then sure fire way to find heater issues is to remove the air intake hose, to give you room. Then bring car to operating temp. Now check, with your hand, the two heater hoses. They should both be hot if heater valve is open. If only one is hot(the one with the valve) check make sure both sides of valve are hot. If other hoseis hot, valve hose is not. Then I'd suspect a clogged core.
Thanks for the suggestion. I just put a Honda thermostat in, so I guessing the heat problem lies elsewhere. I am going to take the fan with out and test it in hot water to see if the resistance drops. I'm actually hoping it doesn't so at least I will have solved part of the problem.
yes check that the heater valve is moving or it could be clogged heater core
Google search "eric the car guy heater core flush"
I don't have that set, but I have the set of three that are similar just not closed. I really could use that set but the 90 degree one kinda does the trick.
Just replaced radiator fan switch, and now the radiator fan comes on when it is supposed to. Both radiator hoses are hot at operating temperature, so the thermostat is opening. I can see both heater valves moving when I operate the heat control. Still no heat. Is it safe to assume that the problem is a blocked heater core, and, if so, what is the best way to go about unblocking it? I'll pick up those tools, to get the hoses off, but what then?
So is the car NOT over heating now? If not, lets now try to solve the heat issue.
First, just me and the way I read your post...."I can see both heater valves moving".....there is only one heater control valve ....picture of these two "said" valve will help.
There's a little door under the dash near the glove box that Honda calls a heater control valve because it's actuated by the heat control dial. This dial also controls a "valve" on the heater hose going to the heater core. This is located on the engine side of the firewall. Both of these appear to be working.
There's a little door under the dash near the glove box that Honda calls a heater control valve because it's actuated by the heat control dial. This dial also controls a "valve" on the heater hose going to the heater core. This is located on the engine side of the firewall. Both of these appear to be working.
To flush the heater, remove the heater hose with the valve in it at the head. Disconnect the hose coming from the core at the firewall(the other end comes off that pipe that runs along the back of the engine, hard to reach). Then get your garden hose...spray water into the heater hose, you should see water coming out of the open heater core pipe at the firewall. If no flow..then either the valve is closed still, or core is still clogged
12-30-2015, 01:24 PM
97 accord heater woes
