Problems starting and temp gauge issue after work on instrument wiring

tottot said:

Re my post above, when trying to sort my starting issue I made up a little jumper cable and plugged one end into the brown live feed [ at relay position] and touched the other end on the white/red to solenoid. Started every time.
Connected small white from ignition switch through a test bulb to the earth [ earth can be tested by connecting bulb brown to black]
This proved there was no power in small white when key turned. I changed ignition unit but this did not help.
This proved issue is/was in the white cable. I did not want to waste time sorting that so.
My fix was to run a cable direct from the white wire position on ignition switch to the starter solenoid. It only needs some 5amp to activate starter solenoid.
Why there is a relay for this job I cant think. Older cars have direct line from ignition to starter method.

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Jumper's a good idea. I'll definitely make one up and keep it in the toolkit for emergencies. Yes, agree about the relay. Seems over the top.

Is the clickeing the glow plug relay? Or is yours under the bonnet

Nothing else clicks near my fuse box(early glass fuse type)

Hicap phill said:

Hope this helps

Ignition off
Brown live 12b
Brown/red 0
Black 0
White/red 0

Start up(12v)
Brown live
Brown/red live
Red/white live
Black 0

Ignition off..
Jump across brown + white/red
Engine will turn over

Ignition on..
same as above but engine will run

Just confirmed the above,standard 4 post relay

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Thanks for this. Totally clarifies what should be happening. Mine's slightly different in that the Brown/Red is white in my case. I think my relay has 5 terminals but the one in the middle doesn't seem to have a connecting cable.

Hicap phill said:

Is the clickeing the glow plug relay? Or is yours under the bonnet

Nothing else clicks near my fuse box(early glass fuse type)

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Ah, could be. I don't actually know where that is, and I don't yet know what the other relays under the fuses are..... Need to find that out..... Wiring diagram (which I THINK is right for my year) also says brake check relay???

patrickr90 said:

Thanks for this. Totally clarifies what should be happening. Mine's slightly different in that the Brown/Red is white in my case. I think my relay has 5 terminals but the one in the middle doesn't seem to have a connecting cable.

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No cable in the middle is correct.

Intermittent is how mine was for a while so I had the under bonnet lash up and then the jumper until I sorted it.
Some other relay behind the main group would click when testing mine [1990 19j]
No glow plug relay on pre Defender model diesels just a heavy duty ignition switch unit. Can be changed without removing the steering lock but one of the screws is a right faf.

Hi. Latest on my woes! The white cable at the relay IS getting a regular supply of 10.3v every time I turn the ignition to crank. I think my early test must have been a mistake. Testing at the back of the ignition switch also gets 10.30v.

Why 10.3v and not 12+v? Does the voltage drop indicate something else going on?

Anyway, it proves there is a supply getting to the relay every time. So, unless the relay doesn't work with a reduced voltage, it points to the relay? But I've swapped it with others and still get intermittent result. I think I'll resort to a jumper lead to get me out of trouble. But i'd like to try to solve the problem at the relay area. I might try buying a new relay. The one I've got is attached and the numbers on it are:

86 87A 87
85 30/51

Can I just walk into an auto shop and pick one up?

Thanks

They are pin numbers.

Voltage readings are not the be all and end all of how well an wire delivers power, if it can not supply sufficient amps things will not work.
This goes for any other connection such as the spade connection on the starter. Poor connection, no starty.
Easy to make up some wires to test a relay direct from a battery.

tottot said:

Voltage readings are not the be all and end all of how well an wire delivers power, if it can not supply sufficient amps things will not work.
This goes for any other connection such as the spade connection on the starter. Poor connection, no starty.
Easy to make up some wires to test a relay direct from a battery.

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Thanks for this. I tested the relay on the bench, as you suggested. Seemed to work well (ie, activated the higher amp circuit), but not in the vehicle. Swapped another relay in and it worked. Either the original relay is unreliable or there's some sort of loose connection in the panel. Relay seems tight when it goes in though..... Will see if it starts in the morning on the swapped relay....

That’s probally an original relay. Mine were like that. Unsure what relay size these are.
I had a (landrover) green 5pin relay laying around & have been using this.

If it’s not the relay causing your problem it’s the ignition switch on the rear of the barrel

Hicap phill said:

That’s probally an original relay. Mine were like that. Unsure what relay size these are.
I had a (landrover) green 5pin relay laying around & have been using this.

If it’s not the relay causing your problem it’s the ignition switch on the rear of the barrel

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Hi. Thanks for that. I'll see what the auto shop has. I'll keep an eye on the ignition switch but it's consistently giving me a reading.

Fingers firmly crossed: I think changing the relay has helped, if not sorted it! It's starting! However, I'm still getting a problem with the temp gauge. Earth issue? In less than 10 minutes, the gauge is climbing well towards the red. I'm killing the engine before it gets there. I'm confused as to whether the black earth cable on the back is just for the lights or interacts with the gauge. If it is integral, I've made sure it is as tight as possible on the back. Does the lock washer go between the cable and the gauge bracket? - ie. is it bracket, washer, cable crimp, nut? Is there any way of ensuring a better ground? I suppose it could be the temp sensor itself, but I'm more suspicious of the gauge because that's what I've been working on. Also have another post about previous water pump noises (now possibly sorted) so it could actually be an overheating issue!

You can check your engine temp with a hand held IR temp reader, aim at thermostat housing, top hose and radiator just after you have stopped.

tottot said:

You can check your engine temp with a hand held IR temp reader, aim at thermostat housing, top hose and radiator just after you have stopped.

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Grand. What should normal temp be?

When up to working temp the thermostat opens to allow coolant to rad.
Most will have a thermostat that opens at 88 degrees so your reading there and on the top hose should be somewhere near that. Top of rad close and the lower down the rad face cooler.

Mismatch between sender and gauge maybe.
I put an additional sender in the top hose and matching additional gauge due to being to scared of the possibility of the thread in the housing getting stripped.
Temp for a 200tdi is in the late 90's apparently.

This post began with a problem with starting and has morphed into other head scratching mysteries. The problem I am now having is related to the starter circuit - but slightly different.

Just to recap, after fiddling with wires behind the instrument panel, I got intermittent start problems. Also a problem with the temperature gauge. I switched relays and this seemed to solve the problem. But I then got a problem with the starter motor engaging after engine startup. See below

I can now be sure of a number of things:

- The engine is not overheating
- The temp gauge is still not working properly but all earth cables on the back are tight
- I began getting a problem with the starter motor engaging again after the engine had started. This seemed to always happen a few seconds after startup.
- So, as a workaround, I've removed the start relay and I've rigged up a jumper across the output terminals. This starts every time and no more starter motor reenergising problems, of course.
- I wanted to know why this was happening so have investigated with a multimeter. With the engine running, it seems that the ground side of the start relay terminals is getting power 14v. This shouldn't be happening! All terminals should be 0v?
- I was wondering whether one of the other relays was causing this so I pulled a relay which I THINK might be the glow plug relay.
- Again, the multimeter says that this relay is getting energised, this time on BOTH the live side and ground side of the control terminals. If I'm wrong about this being the glow plug relay, then I can't think of what other relay it is. All lights and other electrics are off. It can't be a fuel pump (I think I've got a mechanical pump anyway?) because the engine would have died? In any case, it is still continually active while engine is running, even after 30 seconds and COULD be interfering with the start relay ground terminal?.

What could be causing ground to get energised and only when the engine is running?
Is there any systematic way of testing this out?

I have to say, I'm getting more and more baffled!

Thanks, as ever

Are you sure the starter is re-energising or is it just still running?
Aren't some glow plug relays timed, as in they stay on for certain amount of time even if engine is running.?

Don’t know the defender but is the thin wire on solenoid still getting a continuous 12v after you release the ignition switch from cranking