Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 57 plus 4 temperature gauge problem

The temp gauge in my +4 was not connected when I bought it, it is electric and the needle is stationary on normal. If I power it up and earth to ground the needle moves past cold and beyond the scale. So couple of questions, with no power should the gauge rest on cold or hot (silly question probably but not seen it in action before), and is it possible to reposition the needle without breaking it?

Thanks all, Bill

Have you tested the resistance of the sender? The following link (if it works) refers to MGs but indicates the way that resistance should move.

http://books.google.co.uk/books?id=QwyK7...der&f=false

Better may be the information on the Gomog site here:

http://www.gomog.com/allmorgan/instrumentindex.html

and

http://www.gomog.com/panel/response26.htm

I have a 1961 Plus 4. My temperature gauge should be identical to yours -- cream-faced cluster, positive ground.

When the the power is off, the needle moves all the way up beyond HOT. When you turn the power on, the needle slowly drops all the way to COLD.

I would not try to bend the needle. These gauges are very rare and no common car used the same gauge-sender combination.

Thanks Malcolm, great links, am going to try placing the sender in water @ 180F and see if I can recalibrate later today, article refers to a recalibration screw, which if present on mine could sort it. Will not bend needle though.

Interestingly the previous owner had problems with overheating, replaced the radiator but problem continue, but it did have an electric fan fitted to the front of the rad, which I have now removed. I have also replaced the pump with a higher pump rate one from Moss, reviews are mixed so be interested to see if it works. Also the fan blades were a bit flat so have increased the pitch, hence particular importance of the gauge!

Will report back, rgs all, Bill

Bill, I don't want to just keep sending links, but the TR Register forum may also help if you search the threads.

This link is to a cooling problem and potential problems with the pump.

http://www.tr-register.co.uk/forums/index.php?/topic/36711-cooling/page-2?hl= water pump

Half waty through there is a comment about 'cavitation' and excess clearance. One perceived problem of the uprated pumps (if you've got the one with more vanes) is that the impellor thrashes around and causes cavitation. Don't know whether thats a real problem or not! The other occasional problem is that the impellor doesn't sit far enough back in the housing and therefore can't work efficiently.

The gauge on my 1966 car always reads high, but I also have a capiliary type guage which I trust more than the electric one. That rarely shows overheating.

Finally, if you haven't come accross it, there is a looseleaf book, published in the states which specifically deals with the early cars. There's the bedside reader and one called a Yank in Malvern. I have them both and found them helpful despite the cost!

Here's yet another link:

http://morganstuff.com/morgan-bedside-reader.html

Hope you get sorted!

Malcolm

In praise of GoMog!!

I found that whilst my temp gauge worked the sender unit in the radiator is of a later type and works the other way around to the original so I followed the advice offered on GoMog and purchased a cheap gauge from ebay (£4) of the right type and today transfered the new workings to the old gauge, using original needle, so it looks the same as the original from the outside apart from showing cold with the ign off - original shows hot and then goes to cold when the ign is on.

Very pleased with the result, thanks all, Bill

Bill, that's a good bit of lateral thinking. Well done.