School me on the main fuel relay.....

[frozenrice]

As you may guess, I can't get my Integra started. At first I thought it was the main relay. Turn the key one click and there's no typical click of the relay and sound of the fuel pump priming. Keep turning the key I can hear the starter signal relay click (aftermarket), but starter doesn't crank over. Bought a brand new relay, tried several different used ones and still nothing. I've even swapped out the actual ignition harness at the key cylinder.

I should add that I have a lot "not normal" things in the car (MSD external coil/ignition), aftermarket starter signal relay kit, ZIFF socketed ECU, clutch signal bypass (from an auto to manual transmission conversion), aftermarket fuel pump, battery relocation to trunk, so I know it could possibly be one of those things and not to rule them out.

I fail miserably when it comes to understanding electrical, so the question is what/if "inputs" are there in the actual relay to make it all come together to work? I think I've tested/checked the relay wiring correctly but something tells me I've missed something. For example, other than the connection from the ignition switch, does the relay need input from the starter or ECU before it'll work properly? I understand what the relay is supposed to do, just not how it works internally. I think if I can get a better understanding, I might be able to narrow it down to what/if any of those other things might be the issue. :dunno:

[R154]

Usually what goes wrong mostly on a 12v system is a bad ground. Also check to see if you're getting the correct input voltage to the coil. Are the switch side contacts 30/85?

[frozenrice]

The relay I'm dealing with is a typical Honda main fuel relay. I don't think the 30/85 contacts apply here assuming you're referring to generic relays? Like I said automotive electrical isn't my forte so sorry if I sound like a dumbass....

[R154]

I think I misread your post. If you're referring to the start solenoid clicking but the starter not cranking, that's odd. Usually the only thing that goes wrong with a starter is that solenoid.

I think we are looking at the symptoms, not the problem. You said your fuel pump doesn't turn on and prime, nor does your starter function.

Stulid question, but is your battery still good?

The ecu receives power from the keyswitch. The relays that control the fuel pump, and starter do not receive any signal from the ecu. All those relays do is take a low amp signal and close a coil which allows high amp draw to get pulled by the accessories in question.

A schematic would be invaluable for your car.

We have to assume that the car worked in the configuration as it sits before, so determining what changed is going to be the challenge.

[ShermanEF9]

These are notorious for failing on hondas. its from heat cycling, and eventually a solder joint cracks which prevents completing the circuit. you'll really notice it on cold days, it won't start, but if it warms up that day (like with a chinook for example) it might start later.

[ercchry]

Sounds like either a dead battery or bad starter... could be a ground

First thing I'd do is bypass everything and check your fuel pump and starter by running 12v right to them

Then check wiring for the relocated battery... the amount of resistance in a run that long means you need really good connections... do you have a kill switch? Those shit the bed pretty easily in my experience causing a bunch of issues

[ShermanEF9]

what happens to the lights when you put the key to start?

[Neil4Speed]

Originally posted by ShermanEF9
These are notorious for failing on hondas. its from heat cycling, and eventually a solder joint cracks which prevents completing the circuit. you'll really notice it on cold days, it won't start, but if it warms up that day (like with a chinook for example) it might start later.

This was my experience with my Legend, and two 3.5RL's. Its a pretty easy repair, pull out the box from the left of the steering column and you should be able to spot the broken joint pretty quickly. Drop a few solder drops in there and you will be good to go.

[frozenrice]

The main relay was the first thing I tried. Three different ones including a brand new one. I'm assuming you mean the headlights? I've never paid atttention so I'll have to try this weekend when I have a chance.

[relyt92]

Originally posted by Neil4Speed


This was my experience with my Legend, and two 3.5RL's. Its a pretty easy repair, pull out the box from the left of the steering column and you should be able to spot the broken joint pretty quickly. Drop a few solder drops in there and you will be good to go. :werd: Had it happen on my 01 CL.