Temp Gauge/ Battery Light
Hi everybody, I have been a member a few years now and used the forums a lot to keep my D reg 300GD on the road.The information has proved very helpful.
I currently have a problem which I cannot find the answer. Recently the temperature shot straight off the scale when the ignition is turned on, even before the engine has started. Today I changed the sender and still the same thing happened ! I then dug out an old dial I had bought on ebay and swapped for original, temp gauge worked. Then noticed battery light didnt come on with ignition, tested bulb, all ok. I have now swapped back the dial as the old diesel never runs that hot anyway and would rather know whats going on with the charging.
Good job I did as the alternator belt shredded on the way home, noticed instantly when the light came on.
So basically Im asking is the above a coincidence ? Am I missing something ? Anybody know where I can get dials refurbed ? Anybody got some dials for sale ?
Thanks in anticipation
I suspect a earthing issue. To check, disconnect the single post terminal from temperature sensor unit, with the ignition on. Should the temperature shoot upwards, then it is affirmed that the lead is earthing out at some point in the circuit. I suspect the battery light not coming on is related to your earthing issue.
Please give me your chassis number and any information on engine if you are aware it is not the genuine one.
Hi,
The chassis number is WDB4603322705221. I think it has original engine but has been fitted with an after markey tb turbo.
All help much appreciated.
Hi
you have one digit missing in the vin number - should be 17 digits one if the last five is missing
Hi
My guess is WDB 460 332 27 052221 if its an Astral Silver Auto?
Gav
Hi, I think Rakesh is right and this is an earthing problem with the lead to the sender, if you have ruled out the sender itself. I have had a problem with the temperature reading being fine for 1/2 an hour or so, then going up into the red and not moving back despite running downhill and all the other things one does. All was fine if it was allowed 10 minutes to cool, then the cycle started again. After much expensive changing of radiators, thermostats and things it turned out to be a short in the guage when it got warm. I'm offering this as an illustration of what a faulty guage might do. If you do need to have the guage refurbished there is a firm in Wales called Speedy Cables who I'm sure can do it.
Thanks gav you are right with my chassis number. Do you have any further details on my G ? It has a knurled plastic knob to the left of the radio that seems to do nothing and a 'spare cable' under the bonnet as well as a large 'lump' mounted on drivers side wing in engine bay doing nothing.
This weekend Iam going to try to clean contacts on oil light or solder in working temp gauge from another dial I happen to have.
Will let you know how I get on.
the knob and cable are tick over adjuster turn anti clockwise to speed up
dont know what the lump is
Think there is a voltage drop unit in the gauges? This drops the gauges to something like 8 or 10V.. and then it is basic resistor then. This means that gauge does not vary as battery voltage (i.e. if this could be 11.5 to 13.8V .. so scaling issues). However then fuel and temp should be affected.. unless you have wiring issues between regulator and gauge. Other than that earthing/wiring. I always have issues with the fuses on my 1988 300GD but then they work or not.. rather than going off the scale.
Annoying but fortunate at the same time, just thought I would put gauges back in and go for a drive before doing anything to drastic and hey presto temp gauge now working.
Thanks to all for commments and suggestions, will probably have to try one or more in the near future.
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Thanks Rakesh. Tried as you suggested last night, I disconnected sender and turned on ignition and it went straight off the scale again.
Any more suggestions greatly appreciated
Just re read the above. The needle on gauge doesn't move when sensor disconnected and ignition on. Sorry for the confusion