Echo Cooling Fan Wiring Diagram - Toyota Yaris Forums

CT_11_Blue_HB · 06-24-2023, 11:27 AM

Trying to trouble shoot a non-functioning cooling fan on 2002 Echo with 330K miles. I found a wire to the fan connector was chewed through and replaced that. I have confirmed fan works by connecting directly to battery. Have also checked fuses (one in engine bay) and two relays in engine bay, as well as disconnected temp swtich at bottom of radiatior (read that this will turn on fan). Turning on AC does not turn on fan as it should.

Also pulled one of the fan relays and shorted swtiched side in the engine compartment fuse box. Still no fan. Suggests to me something between fuse box and fan.

Any ideas? Thinking a wiring diagram might be useful, but can't find one.

Getting ready to pull fuse box from engine compartment and look for broken or shorted wires.

Thanks!

Cletus Garfunkle · 06-24-2023, 12:16 PM

Id grab a multimeter and just check for voltage on the fuse box before I starting ripping into anything. Like you said you shorted the switched side of the relay and the fan didn't turn on. Id make sure it has voltage. I have a 2001 Echo when I get off work I'll take a look at mine and see if I can add some info. If you Look up "caphector toyota echo manual" on google there should be one that says manual.html idk if that would have a wiring diagram tho but good info incase you could need it.

CT_11_Blue_HB · 06-24-2023, 01:33 PM

Thanks for link to that manual. I'll start working through the steps there for the cooling fan. I may need to put everything back together (battery is out, fuse box opened up) and start from square one on this.

Looks like a wiring diagram is not included there.

One thing that isn't too clear to me is if the switched sides of the two relays are in series or are in parallel. If in series, I would need to short both. Makes more sense in parallel to me, but maybe there iw more to it. Thinking you want the fan to run when:

1) AC off, coolant hot
2) AC on, coolant cool
3) AC on, coolant hot

Do you happen to know if the only fuse to check is the 30 Amp fuse labelled "RDI" in the engine compartment fuse box?

sh0rtlife · 06-24-2023, 08:02 PM

isnt there a ceramic ballast on the left front frame rail that works to control the fan speeds? i know there is on the xb1 which is just an echo with a brick on top

CT_11_Blue_HB · 06-24-2023, 09:13 PM

shOrtlife,

Thanks for pointing that out. Yes there is. Need to check that tomorrow. Was able to find a wiring diagram for cooling system (not sure if it is OK to post link here or not). Plan to use that to troubleshoot.

CT_11_Blue_HB · 06-25-2023, 12:15 PM

Able to get fan running, but not sure why. - Thanks for your help Cletus and shOrtlife!

1) Found the wire to temp sensor had been chewed through, though saw in troubleshooting manual that with that disconnected, fan should go on - will fix this next.
2) Pulled both relays, with car off, could jumper Relay 1 to power Relay 2, then jumpered Relay 2 to get fan to spin fast or slow. That is goodness as I can jumper this and drive car if needed - just need to remember to pull jumpers when I park.
3) Reinstalled Relay 1 leaving Relay 2 jumperer, started car - no fan. Replaced relay 1 with new relay, still no fan. Repeated with Relay 1 jumpered and Relay 2 installed - no fan. All points to something related to control voltage to the relay coils.
4) On a whim, saw that somone on Youtube jumpered pins on AC compressor switch. Did that. With relays installed, fan turns on high when I turn on car.

Thnking issue is AC compressor switch or something in the AC amplifier. Since AC switch is installed in coolant line, feels like I need to take that to someone, but since AC died years ago (maybe because of switch), not pressing. Only issue now is fan runs fast all the time, but at least can is driveable.

I do find it odd that something realted to AC (with is not necesaary) would keep fan from coming on and risk overheating. Feels like overheating prevention should take precendence over AC - maybe this suggestes thatere is something else going on.

Welcome any ideas.

This is about the 4th time I though Echo would have to be put down, but once again it lives! Shooting for 350K miles now!

Cletus Garfunkle · 06-25-2023, 07:35 PM

Weird as shit I should be able to look at my echo today and see if I can get mine to work by jumping or just checking voltages to see when it turns on. I do not have AC either the ac switch in the car does not work/green light doesn't come on which means when I hit the AC Button the fan does not turn on. If the ac pressure sensor shows no pressure I'm guessing it just decides to not run the fan and ac compressor maybe because it doesn't want to just compress air(when the button is pressed). I have never over heated my car yet the fan will turn on when then engine sees high enough temp but shit it takes along time idling to turn the fan on hell even when driving/stopped at a light. Ill see if I can check mine and get back to this thread.

rayfloyd170 · 09-04-2023, 03:42 AM

In your statement below

I do find it odd that something realted to AC (with is not necesaary) would keep fan from coming on and risk overheating. Feels like overheating prevention should take precendence over AC - maybe this suggestes thatere is something else going on.

This is basically what i am asking in this forum But with different condition.

I have overcharged my system with R134a and the discharge line goes above 370psi and activated the Hi Pressure switch.

I find it odd for the pressure switch to switch OFF my Condenser/Rad fan when engine temp is very high (going above 98C/208F). It risks the engine to overheat when temp continues to go up with condenser/rad FAN OFF.

I hope somebody here can share a schematic of Gen3 or Gen2 for the cooling wiring diagram showing the relationship to the pressure switch and condenser/rad fan

06-24-2023, 11:27 AM	#1
CT_11_Blue_HB Drives: 2011 Yaris 5dr HB Auto Join Date: Jun 2012 Location: CT Posts: 11	Echo Cooling Fan Wiring Diagram Trying to trouble shoot a non-functioning cooling fan on 2002 Echo with 330K miles. I found a wire to the fan connector was chewed through and replaced that. I have confirmed fan works by connecting directly to battery. Have also checked fuses (one in engine bay) and two relays in engine bay, as well as disconnected temp swtich at bottom of radiatior (read that this will turn on fan). Turning on AC does not turn on fan as it should. Also pulled one of the fan relays and shorted swtiched side in the engine compartment fuse box. Still no fan. Suggests to me something between fuse box and fan. Any ideas? Thinking a wiring diagram might be useful, but can't find one. Getting ready to pull fuse box from engine compartment and look for broken or shorted wires. Thanks!

06-24-2023, 01:33 PM	#3
CT_11_Blue_HB Drives: 2011 Yaris 5dr HB Auto Join Date: Jun 2012 Location: CT Posts: 11	Thanks for link to that manual. I'll start working through the steps there for the cooling fan. I may need to put everything back together (battery is out, fuse box opened up) and start from square one on this. Looks like a wiring diagram is not included there. One thing that isn't too clear to me is if the switched sides of the two relays are in series or are in parallel. If in series, I would need to short both. Makes more sense in parallel to me, but maybe there iw more to it. Thinking you want the fan to run when: 1) AC off, coolant hot 2) AC on, coolant cool 3) AC on, coolant hot Do you happen to know if the only fuse to check is the 30 Amp fuse labelled "RDI" in the engine compartment fuse box? Last edited by CT_11_Blue_HB; 06-24-2023 at 02:00 PM.

06-25-2023, 07:35 PM	#7
Cletus Garfunkle Average KKT User Drives: 2001 Echo Join Date: May 2020 Location: Direct X Address Posts: 41	Weird as shit I should be able to look at my echo today and see if I can get mine to work by jumping or just checking voltages to see when it turns on. I do not have AC either the ac switch in the car does not work/green light doesn't come on which means when I hit the AC Button the fan does not turn on. If the ac pressure sensor shows no pressure I'm guessing it just decides to not run the fan and ac compressor maybe because it doesn't want to just compress air(when the button is pressed). I have never over heated my car yet the fan will turn on when then engine sees high enough temp but shit it takes along time idling to turn the fan on hell even when driving/stopped at a light. Ill see if I can check mine and get back to this thread. Last edited by Cletus Garfunkle; 06-26-2023 at 11:23 AM.

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06-24-2023, 12:16 PM	#2
Cletus Garfunkle Average KKT User Drives: 2001 Echo Join Date: May 2020 Location: Direct X Address Posts: 41	Id grab a multimeter and just check for voltage on the fuse box before I starting ripping into anything. Like you said you shorted the switched side of the relay and the fan didn't turn on. Id make sure it has voltage. I have a 2001 Echo when I get off work I'll take a look at mine and see if I can add some info. If you Look up "caphector toyota echo manual" on google there should be one that says manual.html idk if that would have a wiring diagram tho but good info incase you could need it.

06-24-2023, 08:02 PM	#4
sh0rtlife Drives: 2007 5dr canadian import Join Date: Dec 2016 Location: pacific north WET Posts: 1,025	isnt there a ceramic ballast on the left front frame rail that works to control the fan speeds? i know there is on the xb1 which is just an echo with a brick on top

06-24-2023, 09:13 PM	#5
CT_11_Blue_HB Drives: 2011 Yaris 5dr HB Auto Join Date: Jun 2012 Location: CT Posts: 11	shOrtlife, Thanks for pointing that out. Yes there is. Need to check that tomorrow. Was able to find a wiring diagram for cooling system (not sure if it is OK to post link here or not). Plan to use that to troubleshoot.

06-25-2023, 12:15 PM	#6
CT_11_Blue_HB Drives: 2011 Yaris 5dr HB Auto Join Date: Jun 2012 Location: CT Posts: 11	Able to get fan running, but not sure why. - Thanks for your help Cletus and shOrtlife! 1) Found the wire to temp sensor had been chewed through, though saw in troubleshooting manual that with that disconnected, fan should go on - will fix this next. 2) Pulled both relays, with car off, could jumper Relay 1 to power Relay 2, then jumpered Relay 2 to get fan to spin fast or slow. That is goodness as I can jumper this and drive car if needed - just need to remember to pull jumpers when I park. 3) Reinstalled Relay 1 leaving Relay 2 jumperer, started car - no fan. Replaced relay 1 with new relay, still no fan. Repeated with Relay 1 jumpered and Relay 2 installed - no fan. All points to something related to control voltage to the relay coils. 4) On a whim, saw that somone on Youtube jumpered pins on AC compressor switch. Did that. With relays installed, fan turns on high when I turn on car. Thnking issue is AC compressor switch or something in the AC amplifier. Since AC switch is installed in coolant line, feels like I need to take that to someone, but since AC died years ago (maybe because of switch), not pressing. Only issue now is fan runs fast all the time, but at least can is driveable. I do find it odd that something realted to AC (with is not necesaary) would keep fan from coming on and risk overheating. Feels like overheating prevention should take precendence over AC - maybe this suggestes thatere is something else going on. Welcome any ideas. This is about the 4th time I though Echo would have to be put down, but once again it lives! Shooting for 350K miles now!

09-04-2023, 03:42 AM	#8
rayfloyd170 Drives: Yaris 2016 1.3 Manual Join Date: Jun 2017 Location: SAUDI ARABIA Posts: 125	In your statement below I do find it odd that something realted to AC (with is not necesaary) would keep fan from coming on and risk overheating. Feels like overheating prevention should take precendence over AC - maybe this suggestes thatere is something else going on. This is basically what i am asking in this forum But with different condition. I have overcharged my system with R134a and the discharge line goes above 370psi and activated the Hi Pressure switch. I find it odd for the pressure switch to switch OFF my Condenser/Rad fan when engine temp is very high (going above 98C/208F). It risks the engine to overheat when temp continues to go up with condenser/rad FAN OFF. I hope somebody here can share a schematic of Gen3 or Gen2 for the cooling wiring diagram showing the relationship to the pressure switch and condenser/rad fan