Odd alternator behaviour

[Jon280]

Went out for a bit of a drive yesterday, and after a few minutes noticed the voltage gauge on the dash was over the end of the scale (i.e more than 16v). As soon as I pulled over, it dropped to the normal 14V, but rose again when I moved off. Stopped, killed the engine, gave it a couple of minutes, then set off again and all was fine.

What could this be? I have only ever experienced alternators not providing enough volts before, never too many. My initial thoughts would be the regulator on the alternator, being faulty, but a bit strange how it misbehaved for a bit, then went back to normal.

Is replacing the regulator (assuming its possible and available) likely to sort this, or is it new/replacement alternator time?

[Jon280]

Will give all those suggestions a check, just recently had a new battery so don't really want to be frying it after only a couple of months! Will get a meter attached to make sure its not just a dodgy gauge, and also check the wiring. Though if a new regulator s pretty cheap may just change that as well as a precaution.

[Jon280]

Well, just been and had a tinker, checked all the wiring and that appears to be sound, and the voltage on the dash ties up with that from a multimeter, although I was getting a nice 14V today. Took the plastic cover off the rear of the alternator to investigate the ease of replacing the regulator, to be greeted with this...



Not a nice simple regulator as I have seen on other alternators.

Think I will just lump for a new alternator, as can get one for around £55 from Euro Car Parts, either a new RTX one http://www.eurocarparts.com/search/401590572/p/hom...
or a reconditioned Lucas one http://www.eurocarparts.com/search/401590571/p/hom...

Any benefit to getting the reconditioned Lucas one over the RTX one? (never heard of RTX...)

[Jon280]

Ahh, that makes my life easier. I was assuming it was the bit around the bottom of the alternator, and for some reason overlooked the metallic box. Have now ordered a replacement, as changing that will be a whole lot easier (and cheaper) than replacing the alternator.

Cheers!

[Jon280]

Well, I have now fitted a new regulator. Found a place not a million miles away from me that were open on Saturday and had the right part for £6. (S and C Electrical in Harlow if anyone needs somewhere similar, they sell on Ebay too).

A decent drive yesterday had the voltage being at what it should be, so hopefully this has solved the problem.