Mi16 Fi And Fp Relays - Details

[GLPoomobile 958]

I opened this topic because I don't want to comment in THIS Wanted topic, as per forum rules.

 

I'm after more details/clarification on the Fuel Injection and Fuel Pump relays for the 1.9 Mi16.

 

I've always seen them referred to as 'the green one' and 'the brown one'. So I assumed the relays were coloured green and brown. Then when I looked at my loom, and the spare I was given, both looms had 2 green relays. But on both looms one relay connector was brown and one green, so I then figured that this was where the naming came from. But looking at Miles' comments on the Wanted topic, it appears that the relays ARE supposed to be different, and ARE supposed to be coloured either brown or green, but seemingly they are interchangeable (?).

 

So I guess what I'd like to know is:

1 - Clarification that the actual relays should be either green or brown

2 - Parts numbers for both

3 - Clarification on what the difference is between the 2 relays

 

I've got a random issue with my Mi not fuelling, which I hope will be a simple relay failure. Like I said, I've got 2 green relays on it. It worked before, so this must be OK, but I'd like to know the definitive answer to how it SHOULD be (as in, how Pug intended).

[Miles 331 1 Cars]

The BX ones are different again, can;t remember which now thou

[GLPoomobile 958]

Anyone else got any input on this?

[DrSarty 90 1 Cars]

*Cat enters pigeon arena*

 

When I made my loom and relay box, I did some research on relays from Hella's web site.

 

To my mind, a relay is pretty much a relay, in so much as they do the same job; some constant and some intermittent. Some have a protective fuse in and some don't. The Hella (.nz site IIRC) was pretty detailed, and thinking about it I'm not quite sure what the black magic is supposed to be.

 

They have current ratings and that's about it. For your use, surely both relays need to be typical constant relays, with 4 pins? Basically, pretty standard relays that you can buy from VWP.

 

Other relays have more pins, some may have a diode and some have a fuse, but I can't see why these relays are so mystical, as they should surely just be a typical, low current, 4-pin relay? My fuel pump and fuel injector relays are these, bought from VWP. Nothing special about them.

 

Can't someone just have a look at theirs, whatever colour they are and just list the make and part number? It would make this so much easier. You can't really go wrong wiring in a relay either, because there's a perfectly clear, explanatory diagram on the casing showing you what goes where.

Edited July 12, 2009 by DrSarty

[timb1046 1]

you say 'intermittent' a relay cannot be 'intermittent' it either has power to the coil and so the front contacts are 'up' or 'picked/energised' or there is no power and so the relay is 'down' or 'de-energised'

 

relays themselfs having fuses in is pretty rare, normaly they will just be protected by an inline fuse on the coil feed.

 

differences between relays are normaly:

 

varing amount of front/back contacts.

 

varing load needed to 'pick' the coil

 

varying current the contacts are able to take before they weld themselfs together.

 

you can also get 'latched' relays where by they will stay up/down depending on what state they were left in and are moved by 2 opposing coils and then latched magneticaly.

 

hope this helps a little?

 

 

more on topic, the fuel relay and the fuel injection are the same type i thought? i would and go and have a look on mine right now but im not near the car today and by the time i am i expect someone will have replied.

[DrSarty 90 1 Cars]

You obviously know more about relays than me dude, but you're confirming pretty much what I said.

 

Just for clarity, when I said intermittent I'm referring to the type of relay used for hesitation/intermittent wiper circuits, and even indicator/flasher relays, which I believe have a bi-metallic strip. Either way these are irrelevant here, it was just me covering relays in a general fashion to attempt to remove some of the myth.

 

The point being that lots of people who make their own looms, for example for aftermarket ECUs, make up a relay box to cope with the injectors and the fuel pump + +. I did, and I bet everyone else who did used a basic, 4 pin relay rated at say 20A (not fused) which you can buy for about £3 each, from VWP or even Halfrauds.

 

How I'm trying to help is to suggest Steve just buys 2 of these and wangs them on.

[GLPoomobile 958]

Well it all sounds simple enough, and really just confirms what I thought.

 

The only reason for seeking any clarification was just because everyone always makes a distinction between them as if they are different parts, working in different ways, to serve a different purpose - i.e. the reference to them being the brown and the green relays. OK, so they serve different parts of the management, but they aren't different between themselves, that's my point.

 

I'd presume then, that the only reason for Pug colour coding the plugs would be for easy identification of them, rather than having to check wire numbers if you wanted to work out which was which (injection or pump relay I mean).

Edited July 12, 2009 by GLPoomobile

[welshpug 1,621]

My thought was that its the Rating of the relay, the fuel pump one being the heftier one as the other relay only supplies the injectors IIRC.

 

then that was proven wrong by servicebox

 

 

 

6555 33 ELECTRIC RELAY 25 AMP VE - GREEN - XU9J4 OUTPUT £14.17

 

6555 48 RELAY 25 AMP - XU9J4 INJECTION FUEL PUMP £20.52

 

There must be something different between them for the £6 difference?

[KRISKARRERA 2 1 Cars]

Shall I try swapping mine around to see if the car still starts?

[welshpug 1,621]

yes!

[paul205mi16 4]

if you swap them the car seems to work just fine, i dont know if one will overheat in the long-run though

[ade 4wd 11]

Both relays are electrically the same and are rated at 25 amps. They are different colours to help with diagnostics so you know what relay does what without having to try and read the numbers on the wires. Peugeot / Citroen also have yellow and violet relays also rated at 25 amps.

[DrSarty 90 1 Cars]

Both relays are electrically the same and are rated at 25 amps. They are different colours to help with diagnostics so you know what relay does what without having to try and read the numbers on the wires. Peugeot / Citroen also have yellow and violet relays also rated at 25 amps.

 

Thanks. My point exactly. Black magic removed; they are just 25A relays, available from VWP etc for about £4 each ish.

[GLPoomobile 958]

Rich, they are actually less than £2 from VWP!

[paul205mi16 4]

Pt Numbers on VWP site?

[KRISKARRERA 2 1 Cars]

Yes, which of these is it? - http://www.vehicle-wiring-products.eu/VWP-...lays/relays.php

[GLPoomobile 958]

Without having a relay to hand, I'm guessing at either R20B or R30A being the ones (so it could be £4 if it's the latter). Or I could be completely wrong and maybe none of them are suitable.

[DrSarty 90 1 Cars]

Without having a relay to hand, I'm guessing at either R20B or R30A being the ones (so it could be £4 if it's the latter). Or I could be completely wrong and maybe none of them are suitable.

 

Why on earth would you say that after all of the myth busting above?

 

It's only a simple 4-blade relay just as discussed and proven. The OE ones are 25A rating and these are 30A. It's only a current handling capability FFS! And the position of the blades is only relevant if you're slotting them into a relay board like the fuse box in the glove compartment. If you're just attaching spade terminals onto wires then it makes no odds.

 

Why oh why are people maintaining the black magic and apparent fear of two piss simple relays?

 

It's R20B @ £1.87 each.

 

This is what I have 3 of in my homemade relay box. One is injectors. One is fuel pump and the other is my manual fan control.

 

Your load circuit goes onto pins 30 & 87, i.e. the injectors or fuel pump. The load circuit also needs a fuse, such as 5A for the injectors and 15A for the fuel pump. This is why some of these relays have fuses in to make installation much simpler. The triggering circuit goes on 85 & 86, where one will be an earth (doesn't matter which) and the other will be an ignition switched live.

 

I'm no electronics engineer but a relay circuit is pretty simple, and the little diagrams of the relays on the VWP page are just like the ones on the Hella page that I learned from. Even if you just look at one diagram, "(1) 4-blade", you can see that the circuit between pins 30 & 87 has a switch in, i.e. the circuit can be broken.

 

The little sausage shaped box with a diagonal line is a little coil which energizes (when you turn on the ignition in this case), closing the switch and completing the circuit allowing the fuel injectors or fuel pump to receive power and operate. When you kill the engine/ignition the circuit breaks again when the switch opens and the power stops going between pins 30 & 87 to the item you want to control.

 

If you can see that the diagonal line box is the coil, which 'pulls' the switch closed by the dotted line (like a rope), and that 85 & 86 are your control mechanism (switch/ign key etc), and that the power for the item flows across the switch between pins 30 & 87 then you can see how all of the relays work and what you'd use them for.

 

As an example, this R20B means a circuit is either on or off. Where as "(3) 5-blade change over" means it'll make one of two circuits on or off.

 

So go spend £1.87 x 2 plus P&P and put this one to bed eh?

 

I really hope that helps.

Edited July 16, 2009 by DrSarty

[paul205mi16 4]

 

If you were to buy a four pin relay, and you disconnect the wires from the origional plastic block, I'd be worried what to do with the spare wire as there are five pins in the one pictured above (off mi16).

I do agree that a relay is just a relay yeah, but it would be much easier to buy a new one of a different brand (ie:cheeper but same quality & five pin) than try to rewire the factory set up, also most people would probably connect the spade connectors and leave for corrosion to take hold causing futher problems.

I recently had a problem that was traced to the relay so took the relay apart to see the condition inside, It was very simple inside but there was a little corrosion that I cleaned up and sprayed some WD40 on after and the realy has been working fine since (2 weeks on)

 

Price is quite different though from what the dealer was after, they told me around £35-40 each!

Edited July 17, 2009 by paul205mi16

[GLPoomobile 958]

There may be 5 pins on the relay, but are there 5 wires connected to it? Cos there ain't on mine! I stripped the loom out of mine, and it had 2 green relays on it, with 4 wires to each. I then compared it to a knackered loom that was donated to me, and that also had 2 green relays with 4 wires to each. I built a complete loom from scratch, all new wires, terminals, housings etc, mirroring the design of the other 2 looms, and it worked (as would be expected, because the original loom worked).

 

I'd also add that it's piss simple (once you know how) to remove the teriminals from the original connectors and swap the positions, so it's not a case of having to cut them off and crimp crappy spades in place. Not that you'd need to swap anything around if you get a relay with the right layout.

 

And Rich, in answer to your confusion over my "maybe none of them are suitable" comment, I wasn't trying to make it any more cryptic than it already is, I was simply disclaiming myself from giving bad advice. Relays may be quite simple, but it's something I'm only just getting used to, and without having an actual relay to hand, from my own car, I didn't want to make a statement about what relay would be suitable without knowing for sure.

[welshpug 1,621]

If you look at the diagrams in the Haynes workshop manual for the 405 [fig 3.29] it does show that they are different, the switching coil is connected to different pins.

 

Both are 5 pin but as noted, only 4 are used, pin 4 on both is unused.

[DrSarty 90 1 Cars]

PSA must've got a bargain bucket deal on 5 pole/pin relays then.