Club 80-90 Forums

Afternoon all.

Scanned the pages already for ’the' good diagram ( there used to be a good one on Wiki, but that seems empty now. )

Problem as follows: Very intermittently, the LED on temp gauge refuses to stop flashing after starting.
The fluid levels are good. If I turn off ignition, sometimes it clears and returns to normal, other times I need to do it a few times.

Other weird ‘happenings’ involve taco needle bouncing erratically when LED flashes problematically, and sometimes the temp needle when driving moves to 3/4 range ( LED never flashes then though. )

I know that’s often considered ’normal range’ but TBH, it isn’t for my van. The needle always sits right on the red LED ( and is always covering some of it at all times when up to temp. ) Weirdly, the next time I drive it, it will sit it its normal position for days at a time - until it doesn’t lol.

It is so intermittent that I am going to struggle fault finding this, so want a bit of a ‘sanity’ check from those with superior experience or knowledge. The plan is as follows;

Remove ‘relay’ 43 from fuse board, and ensuring I keep in mind this will stop low coolant sensor working ( so must keep an eagle eye on it ) I ’think’ I can drive like that for a bit to see if any of the gremlins return.
If they don’t, I can replace that item, if they do return, I need to have a deeper look.

Am I correct here? Viable plan? Being an idiot? 

Feel free to point me right if I am wrong. All input appreciated. I appreciate with the temperamental nature will mean this will rn on and on, but it needs sorting. 
Regards,
S


P.S. I have seen comments where some temp gauges have capacitors that fail. That will be further down the line of things to check once I have eliminated other issues. 

  

I had the same symptoms years ago, it was almost certainly the capacator in the gauge. Used to ignore its random blinking. It is renewable, small soldering job.

Cheers SB.

I’m away in it next weekend. If problem returns I will look to that next. Appreciate input   

The led should flash at ignition on to indicate system self-test iirc, then go off with the engine running.
Flashing and buzzer is what you don't want to see/hear.

silverbullet wrote: ↑23 Mar 2025, 18:09 The led should flash at ignition on to indicate system self-test iirc, then go off with the engine running.
Flashing and buzzer is what you don't want to see/hear.

Yep, that’s it.
‘Relay’ 43 removed, and I do still get the 6 second approx self test flashing.

I have been scanning more posts and reading up on differences between ‘relay' 42 and 43.
Looks like 43 is the early variant and does actually make LED flash and the temp needle increase on low coolant level. Number 42 does not and just gives flashing LED.


As I am also getting that intermittent higher needle reading, if my gremlins do not return, I think I am looking at something wrong on coolant level circuit, or relay itself.

Now it’s just a case of use it and watch it lol. I really do hope it isn’t that capacitor. My soldering is dreadful 

My led flashes when my phone is charging from the lighter socket. Yes really

colinthefox wrote: ↑23 Mar 2025, 20:32 My led flashes when my phone is charging from the lighter socket. Yes really

I’d like to suggest at least ‘something’ to check. My brain cannot contemplate how that’s happening, so by best suggestion is to pencil it in as an ‘upgrade’ 

I definitely have some strange things going on.
After removing ‘relay’ 43 for a while, gauge was fine.

I’ve been reading a few more pages on here and found Robsey’s great description of where relays go in the fuse box.

This is where it gets weird. My ‘relay’ was in position 4. I doubted myself and dug out the photo I took before I removed it. Sure enough, position 4 it was.

Out of curiosity I put it into position 3. Upon doing that the temp gauge doesn’t go over the cool part

As a test I left it in, went for a drive. Temp down near the low end of the scale. Remove ‘relay’ and it goes back to normal range.

It’s multimeter time when I get home I think

Picture before removing:



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I just had to check my notes.
I do hate to give duff information.



In the 87 DG schematic it is No 3.

How weird.

Having never seen my led flash for a true low coolant scenario, I suspect a previous owner had issues and started changing things about.

The only thing that makes sense at the minute in my head is he never fixed it, but putting the relay in the wrong position meant his symptom went away?

The downside to that being right would be I now have my original intermittent flashing LED to contend with ( when it returns ) and the fault a previous owner 10+ yrs ago struggled with


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Mine does this too, intermittently - ever since Mario swapped the engine.
Never did it before.

Happens occasionally on start up...LED flashes and temp gauge does nothing. Only way to stop it is to stop, switch off and restart engine. Then it goes away and everything carries on as normal.
So far, hasn't caused me a problem and everything runs normally. Never continued driving with LED flashing so don't know what would happen if I did and don't really want to find out. I'd like to know what the cause is, but....if it's not actually broke...bla,bla,bla.
Bless him, Mario did tell me about the flashing LED but didn't know why......and it only does it now and then.

Burtybassett wrote:Mine does this too, intermittently - ever since Mario swapped the engine.
Never did it before.

Happens occasionally on start up...LED flashes and temp gauge does nothing. Only way to stop it is to stop, switch off and restart engine. Then it goes away and everything carries on as normal.
So far, hasn't caused me a problem and everything runs normally. Never continued driving with LED flashing so don't know what would happen if I did and don't really want to find out. I'd like to know what the cause is, but....if it's not actually broke...bla,bla,bla.
Bless him, Mario did tell me about the flashing LED but didn't know why......and it only does it now and then.

That does sound exactly the same as my symptom.

You don’t happen to have a taco too do you?
If yes, does the needle bouncing irrationally before cranking give a good indication as to when your LED will not stop flashing ?

My plan has now changed anyway.
When I get home the plan is to test all the circuits one by one with a meter ( focusing on coolant level circuit first )

The LED is intermittent. The low temp reading is permanent when relay is in correct position, so far easier to fix. Then I just need to wait and see if LED gremlin returns


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Smiffo wrote: ↑29 Mar 2025, 17:41

Burtybassett wrote:Mine does this too, intermittently - ever since Mario swapped the engine.
Never did it before.

Happens occasionally on start up...LED flashes and temp gauge does nothing. Only way to stop it is to stop, switch off and restart engine. Then it goes away and everything carries on as normal.
So far, hasn't caused me a problem and everything runs normally. Never continued driving with LED flashing so don't know what would happen if I did and don't really want to find out. I'd like to know what the cause is, but....if it's not actually broke...bla,bla,bla.
Bless him, Mario did tell me about the flashing LED but didn't know why......and it only does it now and then.

That does sound exactly the same as my symptom.

You don’t happen to have a taco too do you?
If yes, does the needle bouncing irrationally before cranking give a good indication as to when your LED will not stop flashing ?

My plan has now changed anyway.
When I get home the plan is to test all the circuits one by one with a meter ( focusing on coolant level circuit first )

The LED is intermittent. The low temp reading is permanent when relay is in correct position, so far easier to fix. Then I just need to wait and see if LED gremlin returns


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Sorry, no Taco. I have a Westie Diesel dash with speedo on one side and rev counter on the other.
My speedo does bounce occasionally, but I've a new hub grease cap for that.
My temp gauge only stops operating when the LED flashes - otherwise all good.
She's coming out to play tomorrow, gonna take her for a drive down to Eastbourne as going out for F-i-L birthday and of course M-i-L Mother's day so will look at relays in the morning during 'Molly the Campervan's pre-flight checks.
I'd be interested to see if my relay is in the correct position ect.

Will report back tomorrow with pics as to how my board is configured.

Enjoy the trip, dude.
Drive safe


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Hopefully, between us all...we can find a solution to what is most probably a common issue