Cresta Temperature Guage

[classic cowboy]

1960 Vauxhall PA Cresta. Why would a temperature guage continue climbing to end of scale well before engine has reached normal running heat and remain there?

[harvey]

Does it do it even before the engine is running? If so disconnect the wire from the sender and if it drops back down then the sender is faulty, if it still stays up then the wire to the sender has shorted to earth. If it's just reading high then the normal cause is a faulty (or mismatched) sender unit.

[Luxobarge]

^^^WHS^^^

Bearing in mind that he means disconnect the sender wire at the sender, rather than at the instrument end.

And if it still does it with no sender wire connected at all (i.e. disconnected at the instrument end) then the short is internal to the guage. So then you get to take it apart and fix it!

That's all assuming that these cars have electrical temperature guages? If Harvey says so then I'm sure thats right, but I merely ask because the one on my Midget did that, and it needed a whole new instrument/pipe/sender tube assembly, as it isn't fixable - not by me, anyway.

Cheers!

[JPB]

According to the Pitman's that covers these cars, the gauge was an aneroid one fed by a capillary on earlier PAs, changing to an electrical type at some stage during production. It would be handy if the publisher had thought to tell the reader at what number this change was made but I'm guessing that there'll be PA aficionados who'll be able to advise further on that.

[harvey]

That's all assuming that these cars have electrical temperature guages? If Harvey says so then I'm sure thats right, but I merely ask because the one on my Midget did that, and it needed a whole new instrument/pipe/sender tube assembly, as it isn't fixable - not by me, anyway.

Cheers!

I hadn't really considered that it might be a capillary guage, but it's a possibility. There won't be a wire to pull off if that's the case, so the OP will soon find out.....

[Luxobarge]

Capilliary - that's the word I was groping for.

Thinking about it, it's unlikely, because if it was it would be reading max the whole time, whether the ignition was on or not, (like mine was) and that doesn't sound like the case from the OP's description.

So Harvey is almost certainly right.

As usual.

CHeers!

[classic cowboy]

Thanx for your responses. Guage is electric not capillary. All minor guages & warning lights appear to share common earth so because temp guage is only one misbehaving sounds like guage is faulty- oh dear
Anyone know anyone who repairs temp guages???

[Luxobarge]

sounds like guage is faulty-

How do you arrive at that conclusion? It's not necessarily the guage, as described by Harvey above - I suggest you do the tests he has outlined to check whether it's the sender, the wiring or in fact the guage itself - statistically I'd have thought that the guage itself is least likely to be faulty!

Cheers