Relay part numbers please

[zed4]

Hi,

I might pop out at lunch to the motor factors and pick up some relays as spares and to try and find out what’s causing the fuse to pop on my fuel pump. I doubt it’s related to the relay, but it won’t hurt to change it and/or to have a spare.

As I understand it, there is a fuel pump relay, and another relay the same – what’s this for? Does anyone have the part numbers of these to hand please? Also, my interior light won’t turn off with the door, so I thought I’d change the timer relay for that to see if that helps, so the number for that would also help.

Thanks,

Dan

[phazed]

All on here.

http://www.parkersteve.dsl.pipex.com/chimaeraparts...

[Oldred_V8S]

Why not just bypass the relay with a piece of wire to ascertain if it is the relay?

[Chuffmeister]

zed4 said:

Hi,

I might pop out at lunch to the motor factors and pick up some relays as spares and to try and find out what’s causing the fuse to pop on my fuel pump. I doubt it’s related to the relay, but it won’t hurt to change it and/or to have a spare.

As I understand it, there is a fuel pump relay, and another relay the same – what’s this for? Does anyone have the part numbers of these to hand please? Also, my interior light won’t turn off with the door, so I thought I’d change the timer relay for that to see if that helps, so the number for that would also help.

Thanks,

Dan

I'd be looking for a short or loose wiring Dan. I'm definitely no expert on auto electrics, but have done a fair amount of DIY house wiring and fuses popping are normally caused by loose wiring or a short somewhere. It would be worth following the live/ neg back from the pump to the fuse box and checking the wires. It may be that part of the protective sheathing has split/ rubbed through; or; the wire has worn through movement.

Edited: It could of course be a faulty fuel pump???

[Snaek]

Dan,

The two relays you are talking about are the fuel pump and main relay located in the passenger footwell, they are odd ball relays with a diode in series with the coil, why I am not sure but for test purposes a standard relay should be ok.
With regards to part numbers check on eBay you can normally pick up the numbers from there. Once you have the number use this site to find alternative part numbers. http://rb-aa.bosch.com/boaarocs/page.jsp;jsessioni...

It is unlikely motor factors will stock this relay. Also if you are popping fuses simply disconnect the fuel pump and make the circuit live if the fuse does not pop the circuit should be ok unless the fault is intermittent, if all seems well check the pump windings, long winded but I hope it works.

Mel.

[blitzracing]

Snaek said:

Dan,

The two relays you are talking about are the fuel pump and main relay located in the passenger footwell, they are odd ball relays with a diode in series with the coil, why I am not sure but for test purposes a standard relay should be ok.
With regards to part numbers check on eBay you can normally pick up the numbers from there. Once you have the number use this site to find alternative part numbers. http://rb-aa.bosch.com/boaarocs/page.jsp;jsessioni...

It is unlikely motor factors will stock this relay. Also if you are popping fuses simply disconnect the fuel pump and make the circuit live if the fuse does not pop the circuit should be ok unless the fault is intermittent, if all seems well check the pump windings, long winded but I hope it works.

Mel.

They are more oddball than that....The two switched connections are tied together unlike bog standard two way relays so it must be the correct Bosch type!

[zed4]

Snaek said:

Also if you are popping fuses simply disconnect the fuel pump and make the circuit live if the fuse does not pop the circuit should be ok unless the fault is intermittent, if all seems well check the pump windings, long winded but I hope it works.

Yes, this is the first plan of attack tonight. To try and rule out either the wiring or the pump. Going to disconnect the pump and leave the wires disconnected, put in a new fuse and switch on the ignition (or activate the circuit for the pump with Rover Gauge). See if the fuse pops or not, if it does, it will indicate a short somewhere on the live.

I'll also try putting a bulb or something in instead of the pump to see if it lights and doesn't blow the fuse to identify a correct and complete circuit.

If all is well, I can then conclude it's probably the pump that's at fault.

But it would be good to have spare relays and understand how it all works anyway.

[Steve_D]

The relay is likely available as a number of different part numbers but the Bosch 0732014112 is a good starting point which will take you to others like the Land Rover part.

You need one that has the following pins.
85
86
30
and 2 pins both marked 87. (Not 87 and 87a or b or c for that matter).

30 is the power into the relay and the two pin 87 are the outputs or loads.
The fuel pump is the most likely culprit and you have spent the day chasing it but it is only one of the loads on the relay.
Pull the relay and connect a wire from pin 30 in the plug to one of the 87 and see if the fuse blows. try it on the other 87.
One will be OK the other will blow the fuse. I believe (it's late and i'm old) the other contact is for the lambda heaters.

So the tell tale is if the fuse does not blow is the pump running.

Steve

[zed4]

Hi Steve,

Turns out my car has new Bosch relays in there anyway.

I've deduced a few things this evening.

1. With the fuel pump disconnected from the yellow wire and the black wire, the fuse still pops when you turn the ignition on.
2. With the fuel pump still disconnected, but the relay removed, the fuse does not pop.
3. There is no continuity between the yellow wire at the pump and ground.
4. There doesn't seem to be any continuity between the yellow wire at the pump and any connectors on the relay.

[Steve_D]

zed4 said:

Hi Steve,

Turns out my car has new Bosch relays in there anyway.

I've deduced a few things this evening.

1. With the fuel pump disconnected from the yellow wire and the black wire, the fuse still pops when you turn the ignition on.
2. With the fuel pump still disconnected, but the relay removed, the fuse does not pop.
3. There is no continuity between the yellow wire at the pump and ground.
4. There doesn't seem to be any continuity between the yellow wire at the pump and any connectors on the relay.

I would still do the 30 to 87 wire link so that you know which circuit the fault is in.

When I do this testing I have an old ammeter with wires terminated in male terminals which I plug in to replace the fuse. If there is a dead short the needle crashes over to the stop. If the circuit is just pulling slightly over the fuse rating it gives further clues as to what is happening.

Steve

ETA When I know it is a dead short somewhere I replace the ammeter across the fuse with a bulb on long wires. If the short is there the bulb will light. Move around the car pushing and pulling thw iring and watch for the bulb to flicker or go out. I found the short on Barries car that way...injector wiring short to the underside of the coil bracket.

Steve

Edited by Steve_D on Tuesday 10th December 07:33

[zed4]

Steve_D said:

zed4 said:

Hi Steve,

Turns out my car has new Bosch relays in there anyway.

I've deduced a few things this evening.

1. With the fuel pump disconnected from the yellow wire and the black wire, the fuse still pops when you turn the ignition on.
2. With the fuel pump still disconnected, but the relay removed, the fuse does not pop.
3. There is no continuity between the yellow wire at the pump and ground.
4. There doesn't seem to be any continuity between the yellow wire at the pump and any connectors on the relay.

I would still do the 30 to 87 wire link so that you know which circuit the fault is in.

When I do this testing I have an old ammeter with wires terminated in male terminals which I plug in to replace the fuse. If there is a dead short the needle crashes over to the stop. If the circuit is just pulling slightly over the fuse rating it gives further clues as to what is happening.

Steve

ETA When I know it is a dead short somewhere I replace the ammeter across the fuse with a bulb on long wires. If the short is there the bulb will light. Move around the car pushing and pulling thw iring and watch for the bulb to flicker or go out. I found the short on Barries car that way...injector wiring short to the underside of the coil bracket.

Steve

Edited by Steve_D on Tuesday 10th December 07:33

Yes, that's the sort of plan of attack I had in my mind as the next step.

The only issue is my multimeter says it's rated to 10A max, seeing as it's blowing a 20A fuse, it may blow it up! I'll have to find another one.

[zed4]

Thanks for the pointer about the lambdas. I did cut the cable ties for these to paint the chassis, although I did cable tie all the wires back afterwards. I wonder if a wire has melted onto the manifold somewhere. I assume that will also pop the fuel pump fuse if it's powered from the same relay.

I'm out all evening tonight, so I'll have another go at it tomorrow night.

[zed4]

Finally! I've found a wiring diagram for the V8S, can I assume this is the same, or at least similar, to the Chimaera?



This shows the pin outs from the relay (number 21), the fuel pump (via the intertia switch) and the lambdas. That will help me immensely.

As far as I can tell so far, the wiring from the main cable connector (number 12) back towards the pump is testing ok on the multimeter. So there's either a problem between the relay and the cable connector (not likely seeing as it runs inside the car where there's no opportunity to short on anything) or there's a problem with the lambda side of the circuit.

I wonder if Rover Gauge will come up with a lambda error...

[spend]

Just put one of your normal relays (fan/lights... with just 4 terms) in and see if that blows the fuse. That will ONLY power the fuel pump and rule out the purge valve circuit. The FPR switches on 2 circuits and you seem to be assuming it is the fuel pump circuit at fault, but the central pin should send power down to the purge valve (and ISTR one variant also powered the lambdas via this circuit ~ but beware there are a few variants of LR loom used).

The more technically savvy would just make a male spade-male spade jumper and short 30-87 then 30-87b to test which circuit is at fault.

[zed4]

spend said:

Just put one of your normal relays (fan/lights... with just 4 terms) in and see if that blows the fuse. That will ONLY power the fuel pump and rule out the purge valve circuit. The FPR switches on 2 circuits and you seem to be assuming it is the fuel pump circuit at fault, but the central pin should send power down to the purge valve (and ISTR one variant also powered the lambdas via this circuit ~ but beware there are a few variants of LR loom used).

The more technically savvy would just make a male spade-male spade jumper and short 30-87 then 30-87b to test which circuit is at fault.

Yes, exactly what I've figured out this morning upon seeing the diagram and reading Steve's post. I will make up some jumpers at work and test the pins out tomorrow night.

[Steve_D]

zed4 said:

.....I wonder if Rover Gauge will come up with a lambda error...

Not very likely as the ECU is looking at the Lambda signal where your circuit is for the Lambda heaters.

Steve

[zed4]

Steve_D said:

zed4 said:

.....I wonder if Rover Gauge will come up with a lambda error...

Not very likely as the ECU is looking at the Lambda signal where your circuit is for the Lambda heaters.

Steve

Ok, yes. I will also need to check item 26 on the diagram, fuel purge valve. I assume this is by the fuel rail?

[zed4]

I've also got this wiring diagram, which is very detailed!

[spend]

Like it says, that is 1992-93 Griffith wiring diagram, the engine loom changed a couple of times... You want to try & find the 95-99 LR Discovery efi on the internet which is probably the closest match.

The purge valve is under the offside headlight, loom runs up the dash down nearside wing, across the nose ... power supplied by FPR and valve activated by grounding at/in ecu.

[zed4]

Right, so I've just bridged out the relay, from pin 30 to each of the pin 87's

Onto the fuel pump and the fuel pump runs perfectly.

Onto the lambda relay and it pops the fuse! Time to try and find where the short it then. There's nothing obviously wrong with the wiring from the lambdas down to the small inline plug.