2004 c70

Matt3691 · Post by **Matt3691** » 21 Oct 2022, 18:14

xanthefin wrote: ↑21 Oct 2022, 11:17 Do you want test the whole circuit from ECM to fan? or
Just to know if fan spins?

For the first one..
How fool it (car) to trigger the fan(s) without such tools? I need at least to know specific engine so i know which specific ECM you have.

Update.

Engine is not a t5....

According to the manual it's either a Volvo B5234 T9. Or a. Volvo B5244 T7

Not sure which one or how you tell....vin# maybe?

So, I turned on the air conditioner today and the radiator cooling fan came on...so we know it works. Unplugged the two yellow communication wires between the two fan relays and jumped each one to ground. Relays and fans worked like they are suppose to. (Two different speeds) let the car idle in the garage and fan never came on.

Back to SQ. One. Guage started at the 6 o'clock spot and slowly moved it's way to the half way mark like it's supposed to.(3 o'clock)

Maybe that's as far as I can go.

xanthefin · Post by **xanthefin** » 22 Oct 2022, 04:44

VIN 6th and 7th letters shows what engine. If not sure write whole VIN. I can maybe help to try tigger via ECM to test fans comes on when should.. if it overheats and fans doesn't kick in i would say temperature sensor surely something but i cannot say without testing.

Post by **Chuck W** » 22 Oct 2022, 05:22

You haven't mentioned replacing the coolant tank cap yet. It could be failing and not holding pressure.

Matt3691 · Post by **Matt3691** » 22 Oct 2022, 11:07

xanthefin wrote: ↑22 Oct 2022, 04:44 VIN 6th and 7th letters shows what engine. If not sure write whole VIN. I can maybe help to try tigger via ECM to test fans comes on when should.. if it overheats and fans doesn't kick in i would say temperature sensor surely something but i cannot say without testing.

That is the number 62 witch crosses to a B2A engine

xanthefin · Post by **xanthefin** » 22 Oct 2022, 13:46

I just did read whole thread of messages and one extra thing did come to mind from my earlier car Ford.

It had Coolant temp sensor located near thermostat so that if you had failing coolant system you didn't get reading from it (there was two put in different ways, other one failed reading).

For easy test no need fancy ways.. just make sure too that all hoses gets warm as a dummy test i didn't yet spot that from your messages so know its looping coolant all the way around. All way up radiator and bottom radiator specially.

I'll look soon whats with that engine possible if any comes up in my mind.

Post by **scot850** » 22 Oct 2022, 16:21

When was the thermostat last changed? It may be sticking closed. Do you know if the temperature gauge is getting up to temperature ok? If you notice it getting to normal position at the 3 o'clock position, and then going higher the thermostat may be sticking? If it takes a long time to get to temperature it may not be closing. Only the first option where it is stuck closed would cause the coolant to flow out.

ECT (engine coolant temperature sensor) which is right beside the thermostat also controls the engine cooling fan. There are threads on how to test this using resistance measurements and ambient temperature to check it is working. Also check the connector near the power steering pump for both its condition, the condition of the wires and corrosion in the connector.

If the ECT is bad, I only recommend the original Volvo OE part.

Neil.

Matt3691 · Post by **Matt3691** » 22 Oct 2022, 17:24

scot850 wrote: ↑22 Oct 2022, 16:21 When was the thermostat last changed? It may be sticking closed. Do you know if the temperature gauge is getting up to temperature ok? If you notice it getting to normal position at the 3 o'clock position, and then going higher the thermostat may be sticking? If it takes a long time to get to temperature it may not be closing. Only the first option where it is stuck closed would cause the coolant to flow out.

ECT (engine coolant temperature sensor) which is right beside the thermostat also controls the engine cooling fan. There are threads on how to test this using resistance measurements and ambient temperature to check it is working. Also check the connector near the power steering pump for both its condition, the condition of the wires and corrosion in the connector.

If the ECT is bad, I only recommend the original Volvo OE part.

Neil.

Everything appears to work as normal. Gauge starts at bottom slowly rises to the middle. The belching happened when my wife turned the car off.

Fitting, box and hose appear fine but that's where the leak comes from....easy to tell. Maybe crack in the box there and when it shuts off tiny bit of overpressure happens at box. Not sure.

What I don't understand is why I never hear the fan come on....so either that's normal, the ecm isn't telling it to come on or the ect sender is malfunctioning strangely.

How does one test the ect.... cold resistance test and hot resistance test?

We have a v70 wagon (t5) and that fan comes on all the time.

Post by **scot850** » 22 Oct 2022, 18:32

Ambient test unless you want to pull a lot of stuff to access it. It does sound like it is overheating on switching off. Normally on the newer cars the fan runs for a bit after switching off.

I am also going on the assumption the fan relay is in the same place on the 2004 C70. It should sit on the top of the radiator under a plastic shroud. There are normally 3 connectors going to the base of it. They are known to corrode and get flaky. This link may be of help in the testing process:

viewtopic.php?t=50336&hilit=Testing+coo ... n&start=10

Neil.

Matt3691 · Post by **Matt3691** » 22 Oct 2022, 19:01

scot850 wrote: ↑22 Oct 2022, 18:32 Ambient test unless you want to pull a lot of stuff to access it. It does sound like it is overheating on switching off. Normally on the newer cars the fan runs for a bit after switching off.

I am also going on the assumption the fan relay is in the same place on the 2004 C70. It should sit on the top of the radiator under a plastic shroud. There are normally 3 connectors going to the base of it. They are known to corrode and get flaky. This link may be of help in the testing process:

viewtopic.php?t=50336&hilit=Testing+coo ... n&start=10

Neil.

Yes, I pulled the relays out and pulled the center plug and jumped them to ground. Fan and relays work as they are supposed to. (Two different speeds)

Matt3691 · Post by **Matt3691** » 22 Oct 2022, 22:56

Thought I'd do some resistance testing of the ect sensor if anyone has the values at day 3 given temperatures.

Also, can someone confirm it has only one temp sensor? I've seen some online that have three wires, one for the guage and two for the ecm.

Just want to know if it can fail one way and not another or if this car has two. Only one I know of is just above the thermostat housing.

Thanks.

2004 c70

Re: 2004 c70