84 coolant warning LED won't stop blinking

[skills@eurocarsplus]

*i've tested, read and tried to find some info, but nothing seems to fit what i'm up against*



the joys of resurrecting the dead

84 vanagon powered by something from the Land of the Rising Sun.

i'm running a 84 wolfsburg cluster (tach and LCD clock)

upon initial running etc the coolant temp LED would do it's initial "test blink" and go dormant until the next key cycle

when i was testing the cluster upon install (needed to swap pins around in the main connector) everything worked as it should.... jump the wires on the low coolant sensor and no light. disconnect them and after a few seconds, the light would flash and the gauge would peg.

after a few test miles the light would keep blinking but the temp gauge as normal (also backed up by a stand alone gauge)

coolant is full, proper 50/50 mix (i did find the TSB on the light blinking)

my foil was weak, but worked. i had a cluster master box on the shelf just for this purpose.

tossed that in. same deal.

what i've checked not necessarily in this order:

swapped out coolant relay- no change

checked for anything goofy in the black box in the engine bay...nothing (everything was cleaned when i did the swap)

power/ground at coolant relay is fine

ground trees under dash recently cleaned/terminals replaced as needed

if i disconnect the blue/green wire from the level sender, light continues to flash and temp gauge pegs out

if i remove the relay and remove the blue/green wire from the level sender the LED continues to blink but the gauge will NOT peg out. this tells me the system is working fine up to this point

would also like to note with relay removed and the TEMP sender grounded the gauge will peg out to hot

so, this leads me to believe that the gauge itself went tits up. any thoughts on this and is it repairable?

i thought i saw a thread where someone said there was something in it that went bad, and can be repaired but it was a total PITA.

looks like i need 255 919 511 which of course is vanagon only, and NLA.

it's the only thing that is making sense that it's internal to the gauge.

the temperature portion (needle) works fine...it just has a constant blinking light
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[DanHoug]

have you polished the stainless steel rods in the level sensor with a 3M pad? get 'em all shiny and retry.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[crazyvwvanman]

If it happens even with the coolant level relay removed it CAN'T be caused by the level sensor or its wiring.

Internal to the gauge is a capacitor that commonly fails and causes the coolant led to blink when there is no real reason. The procedure for replacing it is around.

On the instrument cluster is a 10v regulator that also can be the cause, or it contacts may not be perfect.

On the back of the gauge are 3 nuts that act as contacts to the blue foil and sometimes one of the nuts needs to be cleaned and/or tightened.

Mark

[dobryan]

This may get you pointed in the right direction.

https://www.thesamba.com/vw/forum/viewtopic.php?t=265318&highlight=coolant+capacitor
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Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[skills@eurocarsplus]

thanks guys!

[crazyvwvanman]

The 83 Vanagons were the first to use the coolant level relay but a year or 2 later some other VWs got it as well. Quantums, Jettas, Convertibles, etc but not all, I think only ones from German production.

To open the gauge itself you need to deal with drilling a small rivet. No need to remove both rivets, just one and then pivot the gauge face out of the way. Having the face still attached makes it easier for me. I leave the rivet closest to the temp needle pivot.

Mark

[kamzcab86]

[skills@eurocarsplus]

cool, thanks again. looks like a local place has what i need. i'll get after this in the next day or so.

Mark, that is what i was going to do...swing the face out of the way.

sweet... lets see if i can make a mess out of this
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[skills@eurocarsplus]

well got this all done

just a tedious job, holy shit...i mean magnifying light and jewelers loop kinda shit.

couple of data points....or at least what i notice on my van

-after the repair key on coolant relay OUT the LED flashed and went out before the seat belt buzzer was done

-relay in...again, key on engine off disconnecting the blue/green wire from the level sender would start the needle rising and LED would blink as the temp gauge pegged out. hooking the wire back up without touching the key (still on) shut the LED off after a few seconds and the needle dropped.

many say you have to cycle the key. i found this not to be the case.

either way, it appears to be fixed which is good because having that thing blink while driving was pretty obnoxious
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[Vanagon Nut]

Sounds like fun. Good to know cap replacement worked.

I'm coming from the POV of having installed this part during an air to water cooled conversion but FWIW, though it would involve bit of rewiring, I bet you could upgrade to the later model year coolant low module. That module won't pin the needle in a coolant low situation.

PN
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[skills@eurocarsplus]

^^^^

that seems to be an option. i really don't mind it pegging the gauge as i have a dedicated temp gauge

i know the watercooled factory gauges are more of a suggestion than reality so i decided to run a gauge with numbers.

FWIW, cruising at 70-75 i never hit any higher than 190-192* on a 90* day. that was verified with the ECU. speedhut stuff is by far the most accurate gauge company i have ever found. trans temp never got above 165* (automatic)

anyway, i wanted the system fixed more for a low coolant warning than anything
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[Abscate]

Skills

I’ve found a local ham radio Club usually has guys who can do board level stuff much better and faster than I can , for the usual price of a drink if their best. I take pride in learning a new skill but my Ham friend has the whole setup and lets me watch, too. Sometimes the wives join in as well.
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.ssS!

[crazyvwvanman]

There were 3 versions of the coolant level relay used in Vanagons.
You have the early primitive version.
The early primitive version pegs the temp needle hot when coolant is low, in addition to blinking the led.
The later improved versions only trigger the blinking led while leaving the gauge needle reading for temps.
The early version doesn't need the key cycled to reset the warning.
VW fixed things in 85.

Mark

[Vanagon Nut]