Civic-EG.com Forum 3.3.1

- Sat Aug 01, 2009 4:24 pm #134819 Thanks for the input, Suspended.

Now that I give it some thought, could a faulty main relay cause any of these issues? I've experienced them intermittently but combined I guess they might say something:

Rear defroster comes and goes (dash light comes on, hear relay click but don't seem to get any defrosting action; could be wiring?)
Front wiper (intermittent setting and when you push down on shifter) comes and goes
Dash cluster sometimes doesn't turn on for ~15-20 seconds after headlights are on
Fuel pump/starting issue

More related to my fuel pump, I sometimes faintly smell gas as I approach my car, a bit stronger inside the cabin right as I open the door, but haven't noticed a huge drop in mileage or anything. Something to be concerned about?

- Wed Aug 05, 2009 4:25 am #135557 So I went looking around online for a replacement Main Relay, and several of those I found on eBay and elsewhere had the item listed as "Civic Fuel Pump Main Relay" or something similar.

Considering the part is called the Main Relay, I would imagine it does more than just the fuel pump....or is something like this what I need?

Especially considering that auction lists the problem I'm experiencing

- Wed Aug 05, 2009 8:56 pm #135816

Thanks for the input, Suspended.

Now that I give it some thought, could a faulty main relay cause any of these issues? I've experienced them intermittently but combined I guess they might say something:

Rear defroster comes and goes (dash light comes on, hear relay click but don't seem to get any defrosting action; could be wiring?) Check for 12V on the hot side to ground, check tabs for breakage and then individual lines

Front wiper (intermittent setting and when you push down on shifter) comes and goes check the switch, there is a DIY on here to repair it

Dash cluster sometimes doesn't turn on for ~15-20 seconds after headlights are on check the rheostat (dimmer) switch, i have to beat mine for my dash lights to work

Fuel pump/starting issue Main Relay, re-solder the connections, it controls the ECU, fuel pump and injector power, pretty important...also check all your banjo fuel fittings, shouldn't smell any gas

More related to my fuel pump, I sometimes faintly smell gas as I approach my car, a bit stronger inside the cabin right as I open the door, but haven't noticed a huge drop in mileage or anything. Something to be concerned about?

hope this helps

SiLo's 99 EX Sedan build

[Almost R.I.P.]My EJ1 Turbo SOHC Build - 234whp 212wtq

- Wed Aug 05, 2009 9:34 pm #135852

Thanks for the input, Suspended.

Now that I give it some thought, could a faulty main relay cause any of these issues? I've experienced them intermittently but combined I guess they might say something:

Rear defroster comes and goes (dash light comes on, hear relay click but don't seem to get any defrosting action; could be wiring?) Check for 12V on the hot side to ground, check tabs for breakage and then individual lines

Front wiper (intermittent setting and when you push down on shifter) comes and goes check the switch, there is a DIY on here to repair it

Dash cluster sometimes doesn't turn on for ~15-20 seconds after headlights are on check the rheostat (dimmer) switch, i have to beat mine for my dash lights to work

Fuel pump/starting issue Main Relay, re-solder the connections, it controls the ECU, fuel pump and injector power, pretty important...also check all your banjo fuel fittings, shouldn't smell any gas

More related to my fuel pump, I sometimes faintly smell gas as I approach my car, a bit stronger inside the cabin right as I open the door, but haven't noticed a huge drop in mileage or anything. Something to be concerned about?

hope this helps

Hey BlackSilo, thanks for the tips.

Your first one confuses me a bit though - "Check for 12V on the hot side to ground" - Do you mean at the defroster tab on the hatch glass? In the dash? And when you say "on the hot side to ground", is this just voltmeter red to hot side of (previous answer) and voltmeter black to available ground? Sorry, I'm a bit of an electrical newbie. And as far as I can tell, the tabs themselves are secured and seem undamaged, lines don't seem broken. Would have to inspect everything closer.

And as for the banjo fuel fittings, the only banjo fittings I'm familiar with are at the fuel filter under the hood and on the fuel pump itself. Any others to check or is that it?

Thanks again :-)

- Thu Aug 06, 2009 2:12 pm #135994

Thanks for the input, Suspended.

Now that I give it some thought, could a faulty main relay cause any of these issues? I've experienced them intermittently but combined I guess they might say something:

Rear defroster comes and goes (dash light comes on, hear relay click but don't seem to get any defrosting action; could be wiring?) Check for 12V on the hot side to ground, check tabs for breakage and then individual lines

Front wiper (intermittent setting and when you push down on shifter) comes and goes check the switch, there is a DIY on here to repair it

Dash cluster sometimes doesn't turn on for ~15-20 seconds after headlights are on check the rheostat (dimmer) switch, i have to beat mine for my dash lights to work

Fuel pump/starting issue Main Relay, re-solder the connections, it controls the ECU, fuel pump and injector power, pretty important...also check all your banjo fuel fittings, shouldn't smell any gas

More related to my fuel pump, I sometimes faintly smell gas as I approach my car, a bit stronger inside the cabin right as I open the door, but haven't noticed a huge drop in mileage or anything. Something to be concerned about?

hope this helps

Hey BlackSilo, thanks for the tips.

Your first one confuses me a bit though - "Check for 12V on the hot side to ground" - Do you mean at the defroster tab on the hatch glass? In the dash? And when you say "on the hot side to ground", is this just voltmeter red to hot side of (previous answer) and voltmeter black to available ground? Sorry, I'm a bit of an electrical newbie. And as far as I can tell, the tabs themselves are secured and seem undamaged, lines don't seem broken. Would have to inspect everything closer.

And as for the banjo fuel fittings, the only banjo fittings I'm familiar with are at the fuel filter under the hood and on the fuel pump itself. Any others to check or is that it?

Thanks again :-)

alright, sorry about the defroster confusion....so if your in your back seat looking at the window, you can take the red probe and touch the tab on the right and take the black probe to a chassis ground or the other tab on the other side of the window... you should see 12-14V if the relay, button, fuses and wiring is all intact. funny thing is, with our cars, the light on the button will come on even if the relay/fuse are broken, so you need to measure the voltage and then check the under hood fuse panel for the fuse and relay.

so basically just touch the red one to the right tab and the black one to the left tab, hopefully that clears it up


the only other fittings that i know of are the fuel pump lines under the back seat, there is a rubber return line, a banjo fitting and electrical connections so just check them all out. check the under hood connections to the fuel filter and fuel rail, there should crush washers on all of them and no leaks of any sort. if those are all good, you might want to check the hard lines running under the car, maybe you hit something and damaged them

hope it helps!

SiLo's 99 EX Sedan build

[Almost R.I.P.]My EJ1 Turbo SOHC Build - 234whp 212wtq