Fuel pump relay

buggybugster

Registered User
I have a 90 SC. I turn the key on the fuel pump comes on and the relay kick out. I replased the relay with a new one, turn key on fuel pump comes on then turn key off the relay stays on and so does the fuel pump. To shut the fuel pump off I have to unplug the relay. The relay is no good any more because if plugged back in with key off the fuel pump turns on. Trying to find out what is the problem.
 
Two reasons for the fuel pump staying on after the key is turned off are:-
a) If the new relay is not the correct wattage, the contacts may have shorted permanently.
b) The IRCM has an internal short causing it to turn on the relay at all times.
An easy way to find out if it is (a) or (b) is to turn off or unplug the inertia switch. If the fuel pump then stops working, you may need a new IRCM. If it continues to work, then buy a new relay of the correct type.
 
confused

IRCM is home to the fuel pump relay in a 90 SC as J.D. mentions ...so the question is ..did you replace the IRCM ? ...what relay are you unplugging? the fuel pump uses 2 relays to work ...fuel pump relay and the EEC relay ..the fuel pump relay ....is fed power on a black/yellow wire... from a 30 amp high current fuse ...in the high current fuse box ...and is hot all the time [constant power] ...now to energize the coil part of the fuel pump relay ..ignition switch... is turn on to ...start or run ..this powers the EEC relay ..this in turn sends power ....through the inertia switch [fuel cut off] energizing the coil .....in the fuel pump relay ..there by.. turning the pump on ..now i'm thinking ... you may have a igntion switch problem and should check before buying a new IRCM ..to confirm turn key to off.... and check for voltage.... to the 30 amp EEC relay fuse... in high current fuse box ..... the [G] fuse..with key off.....there should be no power at fuse ..but try turning it on first ..start fuel pump ..then off ..... right next to the EEC relay fuse [G]......in the high current fuse box..... is the fuel pump relay fuse [H] .....and is fed constant power ..make sure it's not shorting to the EEC fuse ..I've seen a melted high current fuse box before ... and can cause weird things to happen ...dave
 
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MercsSC said:
IRCM is home to the fuel pump relay in a 90 SC as J.D. mentions ...so the question is ..did you replace the IRCM ? ...what relay are you unplugging? the fuel pump uses 2 relays to work ...fuel pump relay and the EEC relay ..the fuel pump relay ....is fed power on a black/yellow wire... from a 30 amp high current fuse ...in the high current fuse box ...and is hot all the time [constant power] ...now to energize the coil part of the fuel pump relay ..ignition switch... is turn on to ...start or run ..this powers the EEC relay ..this in turn sends power ....through the inertia switch [fuel cut off] energizing the coil .....in the fuel pump relay ..there by.. turning the pump on ..now i'm thinking ... you may have a igntion switch problem and should check before buying a new IRCM ..to confirm turn key to off.... and check for voltage.... to the 30 amp EEC relay fuse... in high current fuse box ..... the [G] fuse..with key off.....there should be no power at fuse ..but try turning it on first ..start fuel pump ..then off ..... right next to the EEC relay fuse [G]......in the high current fuse box..... is the fuel pump relay fuse [H] .....and is fed constant power ..make sure it's not shorting to the EEC fuse ..I've seen a melted high current fuse box before ... and can cause weird things to happen ...dave
90SC I have power back to the relay in the trunk after the switch is turn on. The relay kicks on the pump turns on then the relay kicks off. There is power to the relay. OK where is the IRCM located an where is the EECM located. NEED HELP Buggybugster
 
ok... I think what you are calling a relay in the trunk is ....the ARC {automatic ride control] and the actuators .... mounted on the shocks.. turning to firm mode ..when you step on the brake peddle..... to start the car ....which would mean you have the ....ride control switch ..in auto position ... in the center console ...beside the fog light switch...turn ride control switch to the firm position ..and the sound you are hearing ...should disappear when you press on the brake ....to start the car ....

The relays are housed in the IRCM [integrated relay control module] a black box...and is located.. behind the passenger head lite.. on the rad support....it's houses the fuel pump relay., EEC relay ..high/low fan relays ..and the A/C wide open ..cut off switch ...this could be fried on the inside ...causing your pump to stay running ...after she's turned off...again I bring you back to the high current fuse box ...located behind the battery ...and checking for power on the [H] fuse [EEC relay fuse]with the ignition turn off ...and check [G] fuse [Fuel pump relay fuse][it has constant power] ...for wiring shorting across to the [H] fuse ..suppyling power to the EEC curcuit ....after the switch is turned off ...if there is no power at the [H] fuse with the ignition off...then most likey the IRCM is bad ....but ignition switchs have been faulty from ford ...and may be the cause of your grief ...dave
 
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buggybugster said:
90SC I have power back to the relay in the trunk after the switch is turn on. The relay kicks on the pump turns on then the relay kicks off. There is power to the relay. OK where is the IRCM located an where is the EECM located. NEED HELP Buggybugster


The fuel pump relay is located under the enertia switch in the TRUNK and is green. I don't have the manual in front of me right now to help you. The fuel pump relay is NOT in the ICRM.

When you turn the key on but do not start the engine the EEC grounds the fuel pump relay for around 2 seconds. If the EEC does not see engine rpm from the cranksensor then it lifts ground to the fuel pump relay. What made you think that the original was bad? What was the problem to start with?

Jerry
 
91

1991 and up had fuel pump relay mounted in the trunk ....dave
 
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MercsSC said:
1991 and up had fuel pump relay mounted in the trunk ....dave


I have a 89 SC and my fuel pump relay is in the trunk. My 90 Cougar LS has the fuel pump relay in the trunk also. Where do you get your info?

Jerry
 
Where do you get your info?

most wiring I have ..comes out of a chilton tbird/cougar 1983-96 which has a great break down of the IRCM or CCRM[Constant Control Relay Module] as they call it ... under emission controls...with wire colors and pin #'s ..and I have traced all the wires to the IRCM .. starting with the black/yellow wire from the fuel pump relay fuse ...to the IRCM on pin#11 ..and have used pin#11 ... to jump start the fuel pump.. throuble shooting...when my low speed fan died ..so I know the fuel pump relay is in the IRCM ..which was replaced with a 89 xr7 IRCM ...so unless Canadian cars were wired different...the fuel pump relay is in the IRCM on 89-90 cars ...dave
 
My understanding is that the "fuel pump relay" inside the IRCM is called the EEC Power Relay on a SC (on a n/a there is an EEC Power Relay in the fuse box near the battery). There is a separate Fuel Pump Relay near the inertia switch in the trunk on SCs and n/as.
 
J.D. said:
My understanding is that the "fuel pump relay" inside the IRCM is called the EEC Power Relay on a SC (on a n/a there is an EEC Power Relay in the fuse box near the battery). There is a separate Fuel Pump Relay near the inertia switch in the trunk on SCs and n/as.


Correct.

Chilton's books that covers that many years are bound to be confusing or wrong. I have replaced my fuel pump relay on my 89 SC and it's inside the trunk. The ICRM controls, the low speed and highspeed fan, a/c clutch, and EEC power. The EEC controls the fuel pump relay that is in the trunk.

Jerry
 
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