T.W. de Haan

Hello All,

Can someone tell me where the Fan timer unit is located at my Honda Accord 1992?

Does anyone know the Original OEM number or an alternative?

Found a unit at the Dashboard fuse box with title 'integrated control unit' with number 38600-SM4-GO1-M1. Is this the same as the fan timer unit or something completely different?

All help will be welcome.

thx

Theo

holmesnmanny

No its different. Assuming you have one and have ac it will be near the dash fuse box and will be 8 pins

T.W. de Haan

Thanks Holmesmanny,

In the wiring schedule I see an eight pin box. There's also one above the fuses but reads Integrated control unit and not Fan timer unit or Timer rad fan. Was wondering if it is the same.

On the internet you also read it might be in the ECU.

Lost Again

What issue are you having?

holmesnmanny

I told you it is different.

The icu plugs into the fuse box. The fan timer is in a bracket on the wall.

Lost Again

OP - your PM is full so I could not send an answer.

Thermo A (t-stat where lower hose connects) controls the FANS (both) when the key is on.

Thermo B (where upper hose connects) controls the fan (one) when the key is off.

----------

So you jumped Thermo A and you stated "the radiator fan came on" - again BOTH fans should come on when doing this. Which fan came on, drivers or pass side?

T.W. de Haan

Thank you Lost Again.

When jumping switch A the radiotor fan comes on so I think the wiring is okay. Switch a was replaced by a new one so that one should be okay as well.

I am looking for the fan timer unit. Any suggestions where it might be? On the internet I found 3 options:
1. O/H fuse box
2. under passengersseat (could not find it)
3. behind the ECU (have not checked)

Lost Again

Still not sure "why" you are stuck on the timer unit - you jump thermo a and the fan works....BTW you still have not answered "which" fan and I keep telling you BOTH fans should come on.

I also asked "what issue" are you having and still haven't seen an answer to that?

Please answer the questions.

I can tell you where the timer is at but I think you are chasing the wrong thing.

T.W. de Haan

The radiator Fan is coming on. In the European cars there is only the Radiator Fan. No AC system so no condensor fan.

The issue is that the car keeps heating up because the radiator fan does not come on. After replacing the Temp Switch A (bottom hose) it still not works.

From the cooling fan relay and temp switch A you can control the fan. Tested the blue wire from the relay to temp switch A (not broken). Tested blue wire from Radiator motor to relay (not broken). Tested ground wire from motor to Ground I (not broken). Tested relay to fuse #39 (20A) (not broken).

So it seems that everything is pointing to things happening before the switches. The cooling fan relay should trigger the relay by putting current on the relay but when the car heats up still no current on the cooling fan relay (blue and yellow). Therefore I am still thinking it might be at a control unit not giving power to the relay and therefore it does not come on.

What do you think?

T.W. de Haan

BTW also checked all fuses and they are okay.

T.W. de Haan

I rechecked all fuse again and fuse 8 dash was out. Replaced with a new one and jump wired switch A. Now the radiator fan is not coming on anymore. ???

Lost Again

THANK YOU, now we are getting somewhere.

I should have known to ask what part of the world you are in....my bad.

Now I will try to explain what I'm thinking.

You can jump thermo a and the fan comes on. So this means that thermo a is not "seeing" the temp that the gauge is "seeing". This also tells me that the timer is fine, think about it, what is the difference in the fan working when the jump is there and when it is not....the "timer" has no idea of the difference.

So I'm down to a few ideas. #1, is there air in the cooling system? There is a bleeder on the t-stat housing, open it with the car off and the heat set to max. SLOWLY add coolant to the rad until a steady stream of coolant is coming out the bleeder.

#2, is the t-stat stuck closed or sticking "half way" open?

#3, are you sure the switch you bought is the correct one? Here in the US many parts stores have/will sell you the wrong switch.

#4, is it possible there is a head gasket leak......what lead up to the issue you are having?

T.W. de Haan

To #3 It was an Original switch bought at our local Honda dealer (I expect that to be fine).

#4 no indication of leaks so I won't go that way.

Leaves #1 and #2;
Your conclusion on the fan timer sounds logical so have to get that out of my head.

I am going to check the t-stat and maybe replace it. But why would that be the problem? If I jump wire the green connector it should 'tell' the car it's too hot and the radiator fan must come on. But when jumpwiring the connector nothing happens.

What's going wrong? It used to work but I still had the same problem. One step forward two steps back.....

T.W. de Haan

I'm trying to upload the wiring diagram I have tested so far.

tech8

Even in the U.S. there are Accords without A/C.

Previously the radiator fan did run when you jumped the Engine Coolant Temperature (ECT) Switch A. If it doesn't now, then check both Under-hood Fuse No. 29 (15A) and Fuse No. 39 (20A).

T.W. de Haan

Rechecked all fuses and they are all okay. By jump wiring the connector at switch A the fan came on now it doesn't anymore.

By jump wiring the cooling fan relay the fan still comes on.

tech8

If the fan comes on by jumping the relay; but, not from jumping the harness connector for Switch A, then it is either:

• Open (break) in black ground wire coming from ground G101 to Switch A. G101 is near the connector for ECT Switch A.
• Open (break) in blue wire going from Switch A to radiator fan relay. Blue wire goes from Switch A connector through Connector C211 and then to relay.

T.W. de Haan

Thanks tech8, but as you look at the wiring diagramm the blue wire from switch A to the relay box has been checked and was okay.

The black wire from switch A to ground I has been checked and was okay. Still trying to figure out what you mean by G101 as in the diagramm it is at the right hand side under the hood (ground I).

Any other suggestions?

tech8

Your photo is not focused; so, it is hard on the eyes to even try to look at it.

1. G101 is on the thermostat housing and is included in the picture I posted, it is near Switch A.

2. Switch A is a normally open-type of switch. When the coolant temperature at the switch is above 90 degrees C, the switch closes, whereby the ground from G101 goes through the switch to the radiator fan relay. By jumping the connector for Switch A, ground goes through directly to the relay.

2. If ground from G101 goes through the relay, then the relay is energized and closes the radiator fan relay contacts (the radiator fan relay is a normally open-type relay); and power then goes through the relay to the radiator fan motor.

In other words, power from under-dash Fuse no. 2 or 8 and ground from G101 energizes the relay, which will subsequently close the relay contact to allow power from under-hood Fuse no. 39 to provide to the radiator fan motor. The radiator fan motor use a separate ground source, from G201; which is located on the right side of engine compartment (fender area).

If ground from G101 does go through to the relay and the relay doesn't energize, then either power is not going to the relay from under-dash Fuse 2, 8 or under-hood Fuse 39; or the relay is faulty.

T.W. de Haan

Thanks tech8 was looking for what might energize the relay. I will see tomorrow if I can find the G101 and check if there is break from the connector of switch A to g101 I meassured directly from the switch to ground I

tech8

Here is a circuit diagram for the radiator fan without A/C. Save it ASAP, as I will remove the image later.

tech8

1. You should turn the ignition to ON after you jumped the connector for Switch A, to see if the radiator fan turned on.

2. If the radiator fan doesn't turn on, with step number 1. Then if A, B, and C are true; then it can possibly be due to the relay, wiring to the radiator fan control module (aka fan timer unit), or the fan timer unit (Honda part # 37740-PT3-A01).

A. Jumping the relay turns on the radiator fan (this means under-hood fuse no. 39 is good, as it goes through the relay).
B. Under-hood fuse no. 29, under-dash fuse no. 2 and no. 8 are all good. (Power from these fuses all go through the fan timer unit.)
C. Jumping connector for Switch A does not turn on the radiator fan (with ignition turned ON).

An alternative to jumping just the two terminals of the connector for Switch A, is to use a longer jumper wire to connect one end to body ground or the negative battery terminal; and then the other end to the terminal for the blue wire for Switch A. Turn the ignition ON.

T.W. de Haan

To your previous message: Found the G101

Incoming wires: blue and black Outgoing: blue Black/Yellow

The black from G101 connects to the black wire of the connector on Switch A
The blue from the connector on Switch A connects to the left top of the relay switch (did not check C211)

Than tested: jumping switch A
1. Radiator does not come on

2a. is true Radiator comes on
2b. all fuse are good
2c. is the same as 1. so jumping swich A does not make the radiator work.

The relay is good; switch with Power window relay which is the same and the windows are workin

Wiring to the radiator. Check at the connection of the motor; put 12v on and it works.
It also works from the relay. Are there important wires to check between relay and motor?

So it might be the fan timer unit. Can you tell me where it is. Only found the integrated control unit above the fuse box inside the car. Don't know where to find the Fan timer unit.

T.W. de Haan

Another thing I noticed. Jumping switch A and ingnition on turn current (12v) on the relay input but the fan doesn't come on. if you connect the other 2 pins of the relay (2 on the right) the fan comes on even when the ignition is off.

tech8

Here are pictures of the location of the fan timer unit for a LHD Accord.

If the motor runs when you jumped the 2 right cavity terminals where the relay plugs in to get it turn on, then the wiring from the relay to the motor and the ground wiring to the motor are good.

The important wires to check now would be:

• Yellow wire from radiator fan control module (aka fan timer unit) to the radiator fan relay. Looks like it may have power at all times.
• Blk/Yel wire from under-dash fuse box to fan timer unit should have power in RUN or START.
• Yel/Blk wire from under-dash fuse box to fan timer unit should have power in RUN.
• Wht wire from under-hood fuse box to fan timer unit should have power at all times.

Also try this, at ECT Switch B, what happens when you jump the connector to Switch B?

I temporarily re-posted the circuit diagram in my previous post #21 above.