40A Fuse getting no power | Ford Escort Owners Association (FEOA)

40A Fuse getting no power

Discussion in '2nd Gen 1991-1996 1.9L SOHC' started by Eldin, May 25, 2019.

  1. Eldin

    Eldin FEOA Member

    Messages:
    8
    Likes Received:
    2
    Trophy Points:
    3
    Thanks in advanced for any advice!

    I have a 1994 Ford Escort LX 1.9 Wagon 5-Speed

    I have recently changed out the:
    Water pump
    Timing belt
    Thermostat to a 195 degree
    Blower Motor Resistor - A/C is working better than ever
    Engine Cooling Temperature Sensor
    Engine Temperature Sender
    Flushed the radiator
    High speed and Low speed relays
    Tested the High Speed and Low Speed fan and it works with no issues
    Cleaned out the Idle Air Control valve using throttle body cleaner

    The issues I am having is that the engine is still overheating til it gets passed the "L" on normal and then the high speed fan kicks in. The low speed does not want to work unless the A/C is on.

    I have traced the problem to the smaller 40A fuse in the Engine Compartment Fuse Box not getting any power and it is going directly to the larger 40A relay causing it to overheat and blow...I have been through many of them now.

    I am wondering if anyone else has experienced the same issue and if so can you recommend a possible fix to get power going to the smaller 40A fuse so my low speed cooling fan will work again.

    I have looked everywhere and the only thing I am waiting to do is trace back the wires to see if there is corrosion or a break in the circuit but I would like some advice first before I dig into that project.

    Thanks again for your advice and expertise. Sorry if this is a re-post as I am new to this site, if another threat exists please direct me to it.
  2. denisond3

    denisond3 Moderator Staff Member

    Messages:
    9,918
    Likes Received:
    2,681
    Trophy Points:
    563
    Location:
    south TX or northern VA
    Welcome to the forums!
    I have two 94LX Escorts. With them, the radiator fan comes on briefly when the ignition is first turned on and the engine is completely cold - like in the mornings. It might run for a second or two. I dont know which speed that is, but I think its the high speed. I think the PCM has to run through its power-on self, then shut the fan off due to the engine being cold: And during the interim, the fan is getting 12 volts to it.**
    According to the explanations in the Service Manual and in the Electrical and Vacuum Troubleshooting Manual (EVTM), I thought the rad fan would always come on the high speed if the a.c. was on. But neither of mine have a working a.c. anymore, so I can't tell.

    There is a relay in the black fuse-and-relay-box beside the air filter housing, to provide power to the radiator fan, which should be enabled anytime the ignition is on. This is due to the way the low speed and high speed fan relays (the ones down inside the driver's side fender) are set up. There is power to one of the relay contacts all the time - though the relay gets power to the energizing coil, which disconnects power to the fan motor. That is how I understand it should work normally.

    Im wondering how you checked that the high speed and low speed fan relays were okay? Its somewhat counterintuitive, since energizing the low speed relay turns the fan on the low speed, but de-energizing the high speed fan relay is how the fan is turned on to its high speed. At least that is how it would seem to work based on the wiring diagrams.
    The relay up inside that box by the air filter housing has had melted contacts on a couple of my Escorts. Its not just the contacts on the relay, but also the contacts on the wires down inside that box. Not easy to get to for fixing.
    I have found that its hard to see if the fuses in the box really are still okay. When they blow out it doesnt cause a darkened smudge. I had to look with a magnifying class to tell.

    I have replaced the radiator fan motors on 2 or 3 of my Escorts (I own and use five of them), and while the new motors had three wires coming from the motor like the OEM ones did, it was really only a single speed motor. They each seemed to cool just fine however, even when in slow traffic where the air temp was 100 f in the shade....and we werent sitting in the shade!

    ** The earlier 2nd gen Escorts also have the fan come on when the ignition is first turned on, but its for less than a second. I can only tell it happens by putting a small piece of white tape on a fan blade. The blade moves when the ignition is turned on.

    Essentially all of the wiring diagrams for the car are in the Electrical and Vacuum Troubleshooting Manual. I have one for each year of my Escorts, (91, 92, 93, my 94s, and my daughter's 95), as they differ from year to year. I got the manuals from ebay, where they are pretty cheap.

    I like the list of things you have replaced.
    Each of my Escorts has a working rad fan and relays. Each summer on a hot day I let each of them idle till the fan would cycle on a couple of times, just to check that the cooling system is still working. The needle on the gauge gets to a different spot on each car. I just want them to be consistent in operation. Once of them gets about halfway between the "L" in normal and the "H" mark at the extreme right. But that is the way that one has always indicated. One of mine has the fan begin running when the needle on the gauge is only up to the "M" in normal. And that is how that car has always indicated.

    It seemed like each year Ford made the word "normal" wider.
  3. Eldin

    Eldin FEOA Member

    Messages:
    8
    Likes Received:
    2
    Trophy Points:
    3
    From what I have tested using a multi meter:

    With the A/C on, I get voltage from the Radiator Fan Connector for the;
    Low Speed setting (black to yellow) wires
    High Speed setting (black to yellow/green) wires

    I have tested the Fan Motor itself jumping the wires from the battery, and both speed settings work on the fan as well.

    With the A/C OFF: I get voltage only to the high speed setting in the Connector (Black to Yellow/Green) wires and not the low speed setting (Black to Yellow) wires.

    I used a multi meter on the terminals of the Black H270 relay and get voltage going to that relay with the A/C off but I get no Voltage for the Green 40A fuse which is supposed to be hot at all times that controls the low speed fan. Which leads me to believe that somehow the Black Relay is getting too much current (staying hot all the time) which causes it to blow. Any time the car is running for too long the Black Relay gets hot to the touch even if the fan is not running, until the car overheats and gets to the "L" or just past the "NORMAL" and then the high speed fan kicks in running for a while on and off until the car gets back to regular temp.

    My dad has owned the car for 17 years and this year he passed it on to me after it started overheating on him and he couldn't figure out the issue. and in those 17 years the car has never made it past the "RM" in "NORMAL" as the low speed fan would run in traffic keeping the engine relatively cool.

    I think it may be a wiring issue in the fuse box not letting the Green 40A Fuse get any power to run the low speed fan before the high speed fan has to do any work. I'm not exactly sure though as I am going to try to take it apart soon to see if there really is an issue, or where the issue is in the wiring.

    It just seems odd that the Black Relay is taking on all of the load for the Radiator Fan and not letting the 40A fuse do its job.

    Another thing I might add is that when I do pull the 30A Fuel Injector fuse the car shuts off and the fan does kick in..

    I have uploaded a file which I believe is the wiring diagram for the cooling system and you can see that the power goes to the 40A fuse before the relay but for some reason I think that in this issue it jumps straight to the 40A Relay.

    UPDATE: I have ground to the Green 40A Fuse terminal but no Power

    Attached Files:

    Last edited: May 26, 2019
  4. denisond3

    denisond3 Moderator Staff Member

    Messages:
    9,918
    Likes Received:
    2,681
    Trophy Points:
    563
    Location:
    south TX or northern VA
    Tomorrow I will try pulling out the fuse for the fuel injection on a couple of my Escorts in the yard. I know the engine will stop, and I will see if the radiator fan runs. Remember, none of mine have working a.c. systems anymore. All discharged.
  5. Eldin

    Eldin FEOA Member

    Messages:
    8
    Likes Received:
    2
    Trophy Points:
    3
    By any chance, would you have the schematics or amy idea of what the three relays do under the dash under the steering wheel? I noticed there is one labeled H270 same as the relay under the hood for the High Speed Fan Relay. Maybe that has blown and has some correlation to the wiring for the low speed and high speed relays and fuses under the hood..? Please let me know.
  6. denisond3

    denisond3 Moderator Staff Member

    Messages:
    9,918
    Likes Received:
    2,681
    Trophy Points:
    563
    Location:
    south TX or northern VA
    All of the wiring diagrams are in the Electrical and Vacuum Troubleshooting Manual. Counting the schematics, the connector pictorials, the component location diagrams, and power/ground connections, there are a couple of hundred pages.

    The H270 part number is one of the more or less standard relays used in several places in Escorts.
  7. Eldin

    Eldin FEOA Member

    Messages:
    8
    Likes Received:
    2
    Trophy Points:
    3
    Changes out two of the relays under the dash, found out one of them is the blower motor relay and the car runs a lot smoother now.

    I am still having an issue with the Low Speed Fan not coming on until the car gets too hot. One thing I did test today was the connector to the fan not getting any power with the A/C off so there must be a short somewhere in the circuit to the green 40 amp fuse not kicking in the low speed fan.

    Gonna do more research and look for the right wiring diagram to the fuse box to see what the issue is.

    If you have any information on that, thanks again in advance.
    denisond3 likes this.
  8. denisond3

    denisond3 Moderator Staff Member

    Messages:
    9,918
    Likes Received:
    2,681
    Trophy Points:
    563
    Location:
    south TX or northern VA
    Just the EVTM, though while it shows all of the wiring that is in the fuse box, I dont think it identifies it as being inside the box.
  9. Eldin

    Eldin FEOA Member

    Messages:
    8
    Likes Received:
    2
    Trophy Points:
    3
    So today I checked out the connections and swapped out some fuses.

    The low speed fan still doesn't seem to be working when the A/C is off but my whole fuse box in the engine compartment is overheating including the Green 40 Amp fuse I swapped out. Any idea as to why this is happening?

    Could it be a faulty radiator fan? Even though it is working when jumping the wires directly from the battery, is there a possibility it is still drawing too much current and overheating my fuses?

    Only other thing I can think of is the PCM Relay on the passengers side that is not sending the signals to the PCM Module to turn on the fan...that is going to be my next test as soon as I am able to hit the scrapyard and maybe get a different relay for that, possibly a different radiator fan if they have one.

    Maybe even a different starter since the wiring diagram shows it is linked to the cooling fan fuses and relays...?
  10. denisond3

    denisond3 Moderator Staff Member

    Messages:
    9,918
    Likes Received:
    2,681
    Trophy Points:
    563
    Location:
    south TX or northern VA
    It is possible the fan motor is partically crudded up, and not turning freely, or has a bad winding on its motor. The only way I know to test would be using a spare fan.
    Eldin likes this.
  11. Swift

    Swift FEOA Donator

    Messages:
    472
    Likes Received:
    88
    Trophy Points:
    278
    If you are at the junkyard grab a spare "fuel injection" relay for the under hood fusebox as well.
    It was this relay that caused my fan problem, which seemed the opposite of everyone else- mine had low speed fan but once it got really hot or turned on ac instead of high speed I had nothing.
    Eldin likes this.
  12. Eldin

    Eldin FEOA Member

    Messages:
    8
    Likes Received:
    2
    Trophy Points:
    3
    Thanks for the advice guys, I'll give an update after I go part hunting this weekend. :thumbsup:
  13. zzyzzx

    zzyzzx FEOA Member

    Messages:
    14,698
    Likes Received:
    1,082
    Trophy Points:
    463
    Location:
    Baltimore, MD USA
  14. Bullethead104

    Bullethead104 FEOA Member

    Messages:
    213
    Likes Received:
    60
    Trophy Points:
    178
    I had the same issue with my station wagon and it ending up being the radiator was clogged three quarters of the way up. So, when I flushed the radiator it had no effect. I was only flushing the tanks and the top quarter of the radiator. I changed the radiator and I'm still using that radiator in my LX. I know this because when I took the radiator out, I opened it to see. Good Luck.
    denisond3 likes this.
  15. zzyzzx

    zzyzzx FEOA Member

    Messages:
    14,698
    Likes Received:
    1,082
    Trophy Points:
    463
    Location:
    Baltimore, MD USA
    That same H270 relay is used for the cooling fan circuit, headlights, and parking lights.

Share This Page