I am beginning to think that my dynamo may not be working properly.
I didnt change it to an alternator as I am not planning on running any extra electrics. It is all new wiring and is wired up correctly as far as I know. But I think it is not pumping out as much charge as it should.

Here's the problem..
I recently wired in a brand new temp gauge and sender.
Its seems to be working ok .. except... it along with the standard fuel gauge read low until I rev the engine right up. If I let it idle, even though the idle is fairly high, they dont move very much off "0" . Once I hold the revs high, they both seem to move up to where they should be.

What do you think the problem could be??

I have ammeter and volt meter gauges that came with the car. Also I do own a multimeter.
Can I use any of these to figure out the problem?

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Tim
Dusk Blue
1964 850

Whack the voltmeter on the battery. Does the needle move when revved? That will tell you if it is charging. Next get a electronic volt stabiliser for your gauges of ebay, cheap as chips.

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The bitterness of poor quality (or Crappy Workmanship) remains LONG AFTER the Sweet Taste of Low Price is forgotten.

Yes sounds like the voltage stabiliser for the instruments could be faulty. It's the small box attached to the back of the speedo. The gauges need a nice steady voltage to work accurately. As suggested the electronic replacements are the most accurate. User "Wombat" used to sell them on here. Even if it is not the stabiliser they are worth fitting IMO.

It's also possible that the voltage regulator for the car is playing up. There is a series of tests outlined in the workshop manual to test this or take to a friendly "old school" auto electrician.

Initially though do the test TK has suggested. Voltage at the battery should rise up to around 14v when the engine is revved.

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68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

One will not get 14 Volt at battery with a generator system. Sorry to contradict you people.

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DID I MENTION THAT I AM THE BEST SUPPLIER FOR MINI ELECTRICAL PARTS AND REPAIRS?
"Let us remove your "SHORTS"

About 13.4 with a tailwind.

Have you checked the adjustment of the Voltage Regulator?

Section N4.

http://www.ausmini.com/manuals/Mini%20W ... System.pdf

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

How much should I see at the battery if all is ok?

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Tim
Dusk Blue
1964 850

Its variable based on the control box adjustment. It will be between 12.7v to 13.3v.
Have a read of the workshop manual above.

There's also a bit more reading available out there. Try this one, it has a few little tidbits of theory in there as well.
http://www.mgb-stuff.org.uk/electricstext1.htm

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Mick, you're on holidays. What are you doing? The wifey is calling.

Nah, I came back yesterday.

I have a pair of Masters subjects to start next Monday.
Six months in SEVEN DAYS (!!) Intensive delivery

A little nervous about it all so lots of pre-reading to do....

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Yeah, was thinking of alternator.

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68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)