I know this is generally an obvious find, but my son just brought the first 2.3 4-cyl Mustang into the family. It's a 1992 notchback which the previous owner must have been having electrical problems with. We installed a new ignition switch and cured most the problems, seeing it was falling apart like most of the ones I've seen. But, the fuel pump is not getting any power to the cut off switch in the trunk at all. I know on all the 5.0 I've owned, the relay is under the seat, which was going to be my next guess. This one is not! I've searched the car in the various locations that it may be located and for some reason I can't find it... Maybe someone pulled it out and that's why the fuel pump isn't working, but I can't find the wiring plug for it either. Can someone please point me in the right direction here?? My boy would really like to hear his new Mustang actually start up! Thanks
Fuel Pump Relay Location?
- Thread starter 2manypony's
- Start date
GTPhreak
Founding Member
its in the box with alot of wires running to it that is on the front side of the passenger strut tower
Still Looking...
I know it's under the seat on the 5.0 Mustangs, but I'm pretty sure I had read a while back that Ford located them somewhere else on the 2.3 for some reason.
I also looked in that circuit board box on the passenger side strut tower and found a short relay that appears to be mounted for life... The relay I picked up at the auto parts store for a 2.3 the other day looks just like the ones for the 5.0 Mustangs which are your normal relay size.
Any further help??
I know it's under the seat on the 5.0 Mustangs, but I'm pretty sure I had read a while back that Ford located them somewhere else on the 2.3 for some reason.
I also looked in that circuit board box on the passenger side strut tower and found a short relay that appears to be mounted for life... The relay I picked up at the auto parts store for a 2.3 the other day looks just like the ones for the 5.0 Mustangs which are your normal relay size.
Any further help??
This, I've had a lot of expierence with. This box is called the IRCM/CCRM(integrated relay control module/contant control relay module). It houses 3 main relays (fan, fuel pump, and eec power). These relays are soldered onto the PCB inside the box, so in order to get to them, you must drill out the rivets. I would recommend going to Radioshack and getting a 30 amp automotive relay. They're 6 bucks opposed to the $130 or so for the box itself. NOTE: The boxes can only be bought used from a vendor such as eBay or new from the dealer. This is why I fixed mine on my own.
Before I tell you how to do it, may I ask if the Check Engine Light comes on when the key is in the ON position?
If so, then the EEC relay is working fine and your problem is just the pump relay.
If not, then it may be your EEC relay and/or the pump relay, but most likely the EEC relay.
Before I tell you how to do it, may I ask if the Check Engine Light comes on when the key is in the ON position?
If so, then the EEC relay is working fine and your problem is just the pump relay.
If not, then it may be your EEC relay and/or the pump relay, but most likely the EEC relay.
Check engine light does come on...
Thank You!! Yes, Once we replaced the ignition switch, the check engine light and the rest of the interior electrical wiring seems to be working. I'll go by the local Radio Shack tomorrow and see if they have a relay that will work. I had already drilled it out and removed the cover to see if it had a relay in there. Hopefully this will get us going. Thanks Again!
Thank You!! Yes, Once we replaced the ignition switch, the check engine light and the rest of the interior electrical wiring seems to be working. I'll go by the local Radio Shack tomorrow and see if they have a relay that will work. I had already drilled it out and removed the cover to see if it had a relay in there. Hopefully this will get us going. Thanks Again!
goland55
Founding Member
If the PCB marks the pinout for the relay (or the relay has it printed on it) you can just jumper across the two switching terminals with a short piece of wire to see if the relay is the problem or not. If the pump comes on when you jumper the relay (with the key in the ignition and in the run position) then you know the relay is probably the issue*. It would suck to desolder the relay only to find out it's perfectly fine and the problem lies elsewhere.
* There could be a problem with the circuit that feeds the inductor side of the relay which causes it to not turn on...this can be troubleshot with a voltmeter probing across hot side of the inductor side of the relay to ground.
* There could be a problem with the circuit that feeds the inductor side of the relay which causes it to not turn on...this can be troubleshot with a voltmeter probing across hot side of the inductor side of the relay to ground.
Only 6.75 volts coming out
O.K. Here is what I've checked so far. I'm only getting 6.75 volts on the wire heading to the fuel pump, once it comes out of the relay in the CCRM. I also checked the codes and it came up with "secondary fuel pump circuit" being an issue.
Is there any chance a bad fuel pump would not complete the circuit and cause issues? I'm not getting any voltage at all at the cut off switch in the trunk. Or does that only kick on during an impact to shut the fuel pump down?
O.K. Here is what I've checked so far. I'm only getting 6.75 volts on the wire heading to the fuel pump, once it comes out of the relay in the CCRM. I also checked the codes and it came up with "secondary fuel pump circuit" being an issue.
Is there any chance a bad fuel pump would not complete the circuit and cause issues? I'm not getting any voltage at all at the cut off switch in the trunk. Or does that only kick on during an impact to shut the fuel pump down?
goland55
Founding Member
If you unplug the fuel pump and then check the voltage at its connector then that would eliminate the possibility of the fuel pump causing the problem.
If you're getting voltage at the fuel pump then the fuel pump relay must be working...though it could have a poor internal connection that is causing the voltage drop. An easy way to check that is to take the voltage across the two switching terminals of the relay when the relay is supposedly on. If there's a significant voltage difference between those two points, the relay is providing a poor connection....the switching terminals should have next to no voltage drop across them when the relay is on. Since you're getting 6.75 volts at the fuel pump and the battery should be at around 12v, the voltage drop would have to be about 5.25 volts....that is significant and would probably cause the relay to get fairly hot.
I would check to make sure that your ground is good from the fuel pump also. With the car off and the fuel pump unplugged, take an ohm reading between the chassis and the black wire on the fuel pump connector. It shouldn't read more than a few ohms. If it shows more than that, you may have a bad ground wire.
You might also want to check to see if the relay module is getting the voltage it needs. The red wire, I believe, should be 5v (I'm guessing 5v because it's connected to lots of other sensors and most sensors run off of a 5v reference). The yellow wire is "hot at all times" and should be the same as the battery voltage.
That's all the ideas I've got at the moment.
If you're getting voltage at the fuel pump then the fuel pump relay must be working...though it could have a poor internal connection that is causing the voltage drop. An easy way to check that is to take the voltage across the two switching terminals of the relay when the relay is supposedly on. If there's a significant voltage difference between those two points, the relay is providing a poor connection....the switching terminals should have next to no voltage drop across them when the relay is on. Since you're getting 6.75 volts at the fuel pump and the battery should be at around 12v, the voltage drop would have to be about 5.25 volts....that is significant and would probably cause the relay to get fairly hot.
I would check to make sure that your ground is good from the fuel pump also. With the car off and the fuel pump unplugged, take an ohm reading between the chassis and the black wire on the fuel pump connector. It shouldn't read more than a few ohms. If it shows more than that, you may have a bad ground wire.
You might also want to check to see if the relay module is getting the voltage it needs. The red wire, I believe, should be 5v (I'm guessing 5v because it's connected to lots of other sensors and most sensors run off of a 5v reference). The yellow wire is "hot at all times" and should be the same as the battery voltage.
That's all the ideas I've got at the moment.
Getting closer
O.K. We installed a new fuel pump this morning and that part is good to go now. I'm getting decent fuel pressure at the relief valve, so I think the fuel system is now working properly.
Car will still not start at this point. It turns over fine but will not fire. I ran the codes again at this point and everything passed except for a code 211 which is the PIP (Profile Ignition Pickup Circuit Fault) This is on a Distributor Less Ignition System.
Can anyone tell me what my next step should be to check this out. As I mentioned before, these 2.3 4-cyl are new to me... Thanks!!
O.K. We installed a new fuel pump this morning and that part is good to go now. I'm getting decent fuel pressure at the relief valve, so I think the fuel system is now working properly.
Car will still not start at this point. It turns over fine but will not fire. I ran the codes again at this point and everything passed except for a code 211 which is the PIP (Profile Ignition Pickup Circuit Fault) This is on a Distributor Less Ignition System.
Can anyone tell me what my next step should be to check this out. As I mentioned before, these 2.3 4-cyl are new to me... Thanks!!
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