coolant level sender

Afternoon folks,

Car is an '83 GTt (tin top). For as long as I have owned it, it has never had a coolant level sender fitted (it's a blanked off coolant tank).
I'm pretty sure it has the woring for one, as I have a connector that looks like the below that has nothing to plug in to:



wires are brown, and blue/red.

The brown Haynes does not have a coolant level sender on the wiring diagrams for an '83 car. However it is on the diagram for '81 models, BUT the wire colours are Yellow/Red and Brown.
What I need to know is what colours they are on an 83 car. If anyone can take a look at theirs, I'd appreciate it.

Secondly, at some point I will probably fit the a new tank and a sender, but when I try and locate the part (251-919-372) the connector on the sender looks completely different - seemingly that is because everywhere seems to only do the 251-919-372/A version. Anyone know where I can get the right version, or am I best changing the connector.

Assuming of course that the connector I have identified is indeed for the coolant level sender!

Thanks all!

J
 

My very early 1800 didn't have the sender and the wiring was clipped to the loom. All appeared factory and not a later bodge.

Thanks for that. That may well be the case - I haven't had a look to see if the associated warning light relay is present.

I have had another dig through the wiring diagrams based on what the 81 showed and I have identified where the components should be - wiring colour matches as well.



No idea why the warning light is flashing though!

If you look at later as in 89-90 cabriolets wiring diagrams, and I think Caddy's they have a coolant level sensor, and a "relay?"

It's a coolant low-level control unit.

paceman said

Thanks for that. That may well be the case - I haven't had a look to see if the associated warning light relay is present.

I have had another dig through the wiring diagrams based on what the 81 showed and I have identified where the components should be - wiring colour matches as well.



No idea why the warning light is flashing though!

Has it always flashed? From cold starts or when it gets hot?

It didn't flash when I took it apart 20 + years ago!
I found a post about it, but that was suggesting that the coolant level relay could be the cuprit, but as I don't have that, I don't know what it could be. It does it as soon as the ignition is on, so it's definately not hot. I know the guage works (earth the sender wire). I guess it could be the sender - but the guage sits at the bottom when the ignition is on, so that would suggest it isn't falsely reading hot.
I should add that the car starts, but then stalls - but that is another issue I have to solve!
 

Unbelieveably, my warning light has started flashing all the time, never done that in 20+ years I've owned the car!

As mentioned above my car doesn't ever appear to have been fitted with the level sender/electronic gubbins so not sure were to start to look?

First thing I'd check is that the guage works properly. If you briefly earth the sensor wire, the guage should start to move. Only do it briefly as they aren't meant to have a circuit straight to earth - you can burn out the wires in the guage.
I've been doing a load of reading up, and found on a VW bus forum that the capacitor in the guage can go bad. I decided to take a look at mine - sadly, the Motometer guage's in mine are a bit tricker to remove than any online teardown videos would suggest. I have ended up with this….



I really didn't want it to go that far! Problem I now have is I'm not sure how I can test the guage in isolation - but I'm working on that. I can't easily change the capacitor as the board is fixed completly differently to the ones discused on the bus forum! I'm going to try and reverse engineer the circuit - it's a basic flasher circuit built round a 741 op-amp (I did electronics many many many years ago) and see if I can work out what triggers the flashing. My guess is that is is the falling resistance of the sender as it gets hot. If the capacitor is at fault then I'm going to have to get creative about how I fit a new one as I can't get to the back of the circuit board.

I'll keep you updated as I progress - if I work out that the guage circuit is fine then I can work backwards, but given it's only controlled by one input wire (which I know is ok) it must be the guage circuit somewhere….

The guage works perfectly. The red LED flashes normally with ign on, I think it always did and should do as a self check like the oil pressure warning lights.

When the engine starts it flashs very fast and sometimes goes back to normal flashing speed. A couple of times its worked normally and gone out. Not using the car much due to various reasons so not sure if its going to go away on its own or not (problem arrived on its own, lol)

Reading up its relay position 18 top right of the fuse box, its empty on mine but there appears some wiring behind but not had a proper look. Car back parked up in garage after having to replace/rebuild rear brakes to get it through MOT this week in 30degree heat so I'm all MK1'd out at the moment…..

My fuse box is the same. Although if there is no relay, and no level sender, that can't be the culprit as the tests say 'remove the relay to see if the flashng stops'. Plus, if you never had one and it worked…..

Poor connection on the multi plug to the clocks.
I had an issue on my cabby with flashing light.
Ok it’s a different beast but it turned out to be a poor connection between the plug and the blue film copper contacts that fit over the plastic nub.
I put couple turns of electrical insulation tape around the nub, cleaned the contacts up on blue film and have the loom plug a squirt of servisol contact spray cleaner.
Fitted it all back together and never had a problem since.
I’m not saying yours is the same cure, but I spent ages faffing with bits n bobs.
Luckily mine was a simple fix.
Old contacts just get dirty including those that do the wipers and indicators.
I’m now a go to clean the contacts first on everything.
Had similar for a horn once.
Pulled loads of stuff about when all it needed was the relay pins cleaning.


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chortle said

Poor connection on the multi plug to the clocks.
I had an issue on my cabby with flashing light.
Ok it’s a different beast but it turned out to be a poor connection between the plug and the blue film copper contacts that fit over the plastic nub.
I put couple turns of electrical insulation tape around the nub, cleaned the contacts up on blue film and have the loom plug a squirt of servisol contact spray cleaner.
Fitted it all back together and never had a problem since.
I’m not saying yours is the same cure, but I spent ages faffing with bits n bobs.
Luckily mine was a simple fix.
Old contacts just get dirty including those that do the wipers and indicators.
I’m now a go to clean the contacts first on everything.
Had similar for a horn once.
Pulled loads of stuff about when all it needed was the relay pins cleaning.


Sent from my iPhone using Tapatalk

All contacts have been cleaned (on everything) and I've done the tape trick. Guage moves so I know it's getting the feed…..I suspect it's the circuit int he guage itself…