Technical temp gauge fault variation

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Technical temp gauge fault variation

Big Bed

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Mar 31, 2016
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2003 2.8jtd
Hi, I have done the lead disconnect from back of dash and also checked fusebox under bonnet for any damage ( clean and tidy, looks like new on all connectors).
However my temp gauge is being increased by activating other electrics. It rises with each step of the blowers and again with the turning on of lights, at the point I turn on dipped beams the radio also switches off and and on, this coincides with the slight dip in revs as the alternator demands more revs to supply demand. I only noticed the alternator dip on tick over as when travelling not noticeable. Could the problem be with the alternator in some way giving a split second loss of juice ( which is why the radio switches off)?
Clutching at straws a bit with guesses as not good with electrics as you may have realised.
Should add, the gauge sits at halfway unless other electrics switched on. Up till now it has risen to that point and stayed there.
TIA
 
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You have a defective voltage regulator. It sits on the back of the alternator and also houses the carbon brushes. Easy to replace once you have access to it, in some vehicles you have to remove the alternator first.
 
You have a defective voltage regulator.

Or earth.

Measure the voltage unloaded, then load with full headlamps, blower motor etc. measure again. and measure the voltage drop accross the earth.
 
"You have a defective voltage regulator. It sits on the back of the alternator and also houses the carbon brushes. Easy to replace once you have access to it, in some vehicles you have to remove the alternator first"
Thank you, I will have a look at that.
 
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Or earth.

Measure the voltage unloaded, then load with full headlamps, blower motor etc. measure again. and measure the voltage drop accross the earth.

Thank you, I visually looked at earths which "look" ok, to do what you ask where do I (being a bit of an electrical thickie!) where do I measure from, ie where do I place the pos and neg probes of the multimeter?
Thanks
 
You have a defective voltage regulator. It sits on the back of the alternator and also houses the carbon brushes. Easy to replace once you have access to it, in some vehicles you have to remove the alternator first.
Having run out of other possibilities I am now trying to find a regulator, I can get a complete alternator but not looking forward to swapping the whole unit, looks like I have access to get the regulator off without removing the alternator though. Fingers crossed.
 
Decided to get auto electrician involved. The problem is now rectified. It did tur out to be an earth fault. He found a faulty earth behind the dash on the passenger side which leads through the bulk head, this he replaced and now the temp gauge is back to normal and the blowers and lights don't cause a voltage drop. Hope it helps someone else one day. :)
Thanks for all the input and suggestions.
 
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