Radiator Fan Not Coming On - Overheating

I have a 1994 Civic VX, and it is slowly overheating. On cold days,
city driving, I don't even notice it. But on a hotter day or longer
drive after about 15 minutes of driving the car starts to overheat.
If I turn on the car heater at it's lowest setting it cools the engine
back down.

I have looked at the fan and it doesn't seem to be coming on. Could
this be it?

I've taken it to a mechanic and paid for a new head gasket/thermostat
and that wasn't it.

Thanks!
John McConnell
Vermont

 

If the fan is not ever working--that is the source of the problem.

 

If the fan is not ever working--that is the source of the problem.

 

(Ted Jackson) wrote in :

Could be the engine coolant temp (ECT)switch or the fan motor itself.
You can test the fan motor,I believe,with a pair of clip leads direct to
the battery. The ECT would need an ohmmeter and run the engine until it
warms up and see if the switch closes.

The ECT is on the thermostat housing,near the block,if it's similar to my
94 Integra.

 

(Ted Jackson) wrote in :

Could be the engine coolant temp (ECT)switch or the fan motor itself.
You can test the fan motor,I believe,with a pair of clip leads direct to
the battery. The ECT would need an ohmmeter and run the engine until it
warms up and see if the switch closes.

The ECT is on the thermostat housing,near the block,if it's similar to my
94 Integra.

 

The problem could also be the fan relay.

It might be the easiest item to check. I'd borrow a manual from the library to
help find it and for directions on testing. Or you could trace the fan motor
electrical connections to the relay. Or you could use the following for
guidance:

Drawing to help with locations (note this is a 1995 and later Civic):
http://www.honda.co.uk/owner/CivicManual/pdf/23-a7.pdf

For a 1993 Accord (includes directions for testing the relay):
http://www.honda.co.uk/owner/AccordManual/400/16-103.pdf

 

The problem could also be the fan relay.

It might be the easiest item to check. I'd borrow a manual from the library to
help find it and for directions on testing. Or you could trace the fan motor
electrical connections to the relay. Or you could use the following for
guidance:

Drawing to help with locations (note this is a 1995 and later Civic):
http://www.honda.co.uk/owner/CivicManual/pdf/23-a7.pdf

For a 1993 Accord (includes directions for testing the relay):
http://www.honda.co.uk/owner/AccordManual/400/16-103.pdf

 

Drawing to help with locations (note this is a 1995 and later Civic):

Hi there, you wouldn`t happen to have a link to 94-97 Accord? I am having
problems locating pieces of the DRL system.Thanks

 

Drawing to help with locations (note this is a 1995 and later Civic):

Hi there, you wouldn`t happen to have a link to 94-97 Accord? I am having
problems locating pieces of the DRL system.Thanks

 

No, I don't have one that's dead on for the 94-97 Accord.

The main resource I use for part locations on the car is

http://www.hondaautomotiveparts.com/auto/jsp/mws/catdisplay.jsp .

It's a Honda parts company's site, but when one goes looking for parts there,
the drawings that come up are very good.

Otherwise, online manuals appear at
http://www.honda.co.uk/owner/workshopmanuals2.html

It has links to manuals for:

1995 - 1997 Civic Manual
1991 - 1993 Accord Manual
1990 - 1994 Concerto Manual
1988 - 1991 CRX Manual
1988 - 1990 Prelude Manual
1988 - 1990 Legend Coupe
1984 - 1987 Civic Manual

Sometimes I piece together the solution to my 1991 Civic's problems by going to
a few of these manuals.

When I've really had it I go to my public library and get the Chilton's manual
for my specific car.

Of course I ask here a lot, too. Maybe you want to ask here?

DRL = daytime running lights, correct?

 

No, I don't have one that's dead on for the 94-97 Accord.

The main resource I use for part locations on the car is

http://www.hondaautomotiveparts.com/auto/jsp/mws/catdisplay.jsp .

It's a Honda parts company's site, but when one goes looking for parts there,
the drawings that come up are very good.

Otherwise, online manuals appear at
http://www.honda.co.uk/owner/workshopmanuals2.html

It has links to manuals for:

1995 - 1997 Civic Manual
1991 - 1993 Accord Manual
1990 - 1994 Concerto Manual
1988 - 1991 CRX Manual
1988 - 1990 Prelude Manual
1988 - 1990 Legend Coupe
1984 - 1987 Civic Manual

Sometimes I piece together the solution to my 1991 Civic's problems by going to
a few of these manuals.

When I've really had it I go to my public library and get the Chilton's manual
for my specific car.

Of course I ask here a lot, too. Maybe you want to ask here?

DRL = daytime running lights, correct?

 

If your DRL is not working (right high beam never turns on for example
and the DRL warning light is on in the dashboard), it's most likely
because the DRL control module is broken. I had that problem in my old
94 Accord EXR.

The module is located under the steering column, you'll only see the
bottom side. It's gray, about the size of a pack and a half of
cigarettes, and it has a blue connector. To remove it, push up. Take it
apart and look at the solder points on the PCB inside. Most likely they
have hairline cracks in them, but they are extremely easy to resolder.

I did this repair on my Accord, and the DRLs were still working just
fine when I traded the car in for my Prelude.


Cosmin

 

If your DRL is not working (right high beam never turns on for example
and the DRL warning light is on in the dashboard), it's most likely
because the DRL control module is broken. I had that problem in my old
94 Accord EXR.

The module is located under the steering column, you'll only see the
bottom side. It's gray, about the size of a pack and a half of
cigarettes, and it has a blue connector. To remove it, push up. Take it
apart and look at the solder points on the PCB inside. Most likely they
have hairline cracks in them, but they are extremely easy to resolder.

I did this repair on my Accord, and the DRLs were still working just
fine when I traded the car in for my Prelude.


Cosmin

 

I have a 1994 Civic VX, and it is slowly overheating. On cold days,

A while back, I had the same problem with the A/C fan on my Accord. Found
out it that the connector inside the main fuse box had vibrated loose (from
the bottom). Here's what I had followed to determine that: (Post was
before loose connector was discovered).

1998 Accord, EX V6, Sedan, 120K mi.
I used a Haynes (42014) auto manual to diagnose the following:
-Condenser fan no longer turns on at all, either when the engine is above
~217 degrees or when the A/C is engaged.
-Coolant fan works with no issues.
-On this car, the Condenser fan is located on the passenger side (flatter
motor).
-I used jumper wires to directly connect the fan to the battery and it does
work.
-I have checked drivers-side fuses #3 and #6 and both are good.
-I have checked the engine fuse box condenser fan fuse and it is good.
-I pulled out the condenser fan relay and placed 12VDC across it's terminals
#3 and #4. At this point, it does show continuity between terminals #1 and
#2 as it should.
-With the relay removed, I checked the engine fuse box relay socket with a
volt-meter. Voltage at the sockets for terminals #3 and #4 on the relay do
produce 12VDC when the A/C is engaged. This should allow the relay to close
#1 and #2. This tells me that the fan control module in the passenger
compartment is working.
-With the engine off and the relay removed, the relay socket for terminal #1
does show +12VDC as it should (wiring diagram shows always hot -- via engine
fuse box 20A fuse already checked).
-Looking at the wiring diagram in the service manual, relay socket #2 should
directly connect to the BLU/YEL wire on the fan electrical connector. It
does *NOT* show continuity.
-The BLU/YEL wire does not have continuity to ground either at the box or at
the fan connector (check to make sure that it is not grounding out).
-The fan connector BLK wire does have continuity to ground as it should.
-Checked the fan connector on the wire and it appears in working order with
continuity to the immediate wire.

I tried this procedure on the working coolant fan and it all checks out. If
the BLU/YEL wire directly connects the fuse box to the fan, I assume there
is a break in the line. I have checked as extensively as possible and do
not see any signs of fraying or damaged insulation. Unfortunately, I can't
access most of the wire since it is bundled to tell where the break is. Not
sure why only one wire in the bundle would be damaged unless it's on the
outside somewhere that I couldn't see with my flashlight.

 

I have a 1994 Civic VX, and it is slowly overheating. On cold days,

A while back, I had the same problem with the A/C fan on my Accord. Found
out it that the connector inside the main fuse box had vibrated loose (from
the bottom). Here's what I had followed to determine that: (Post was
before loose connector was discovered).

1998 Accord, EX V6, Sedan, 120K mi.
I used a Haynes (42014) auto manual to diagnose the following:
-Condenser fan no longer turns on at all, either when the engine is above
~217 degrees or when the A/C is engaged.
-Coolant fan works with no issues.
-On this car, the Condenser fan is located on the passenger side (flatter
motor).
-I used jumper wires to directly connect the fan to the battery and it does
work.
-I have checked drivers-side fuses #3 and #6 and both are good.
-I have checked the engine fuse box condenser fan fuse and it is good.
-I pulled out the condenser fan relay and placed 12VDC across it's terminals
#3 and #4. At this point, it does show continuity between terminals #1 and
#2 as it should.
-With the relay removed, I checked the engine fuse box relay socket with a
volt-meter. Voltage at the sockets for terminals #3 and #4 on the relay do
produce 12VDC when the A/C is engaged. This should allow the relay to close
#1 and #2. This tells me that the fan control module in the passenger
compartment is working.
-With the engine off and the relay removed, the relay socket for terminal #1
does show +12VDC as it should (wiring diagram shows always hot -- via engine
fuse box 20A fuse already checked).
-Looking at the wiring diagram in the service manual, relay socket #2 should
directly connect to the BLU/YEL wire on the fan electrical connector. It
does *NOT* show continuity.
-The BLU/YEL wire does not have continuity to ground either at the box or at
the fan connector (check to make sure that it is not grounding out).
-The fan connector BLK wire does have continuity to ground as it should.
-Checked the fan connector on the wire and it appears in working order with
continuity to the immediate wire.

I tried this procedure on the working coolant fan and it all checks out. If
the BLU/YEL wire directly connects the fuse box to the fan, I assume there
is a break in the line. I have checked as extensively as possible and do
not see any signs of fraying or damaged insulation. Unfortunately, I can't
access most of the wire since it is bundled to tell where the break is. Not
sure why only one wire in the bundle would be damaged unless it's on the
outside somewhere that I couldn't see with my flashlight.

 

Thank-you for the links. Already in my favorites. Yes DRL is daytime running
lights.

 

Thank-you for the links. Already in my favorites. Yes DRL is daytime running
lights.

 

I thought that was it aswell. I took it (control module) apart and
resoldered it.
Still as in your example right high beam did not function and I had the DRL
light on
in the dash. My brother happens to have the same car as I do, so I decided
to trouble shoot
and take his out and try his on mine and put mine in his. Well you guessed
it, mine
works well in his car but his still appears to be unserviceable in mine. So
now out of
luck. I followed the wires best I could but still nothing. I was hoping
maybe having a better wiring
diagram or just some dumb luck that someone else might have run into the
same thing.
Continuity check to the fuse box from the right highbeam is good on one
wire but not on the other.
I hope it is nicer tomorrow and will give it a another shot. Thanks
guys/gals.

 

I thought that was it aswell. I took it (control module) apart and
resoldered it.
Still as in your example right high beam did not function and I had the DRL
light on
in the dash. My brother happens to have the same car as I do, so I decided
to trouble shoot
and take his out and try his on mine and put mine in his. Well you guessed
it, mine
works well in his car but his still appears to be unserviceable in mine. So
now out of
luck. I followed the wires best I could but still nothing. I was hoping
maybe having a better wiring
diagram or just some dumb luck that someone else might have run into the
same thing.
Continuity check to the fuse box from the right highbeam is good on one
wire but not on the other.
I hope it is nicer tomorrow and will give it a another shot. Thanks
guys/gals.

 

THANKS FOR THIS IDEA AND OTHERS! I talked to the mechanics and they
felt bad it wasn't fixed and said they would try anything I came up
with to see what it could be, since they are stumped. I'll pass on
these ideas and let you know.

John