Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 Alternator failure

I have a 1992 4/4 with the Ford 1600 CVH Efi engine, I have had the car since 2010 and have had constant problems with the Alternator failing.
I have been told that it is due to the rear of the Alternator being too close to the exhaust manifold causing it to overheat, the manifold has been lagged but
does not seem to make much difference. I know that if I replace the Alternator and do a longish trip it will fail again, not completely but the output drops to <12v and does not increase when the revs are increased.

Has anyone else experienced this problem and if so how was it resolved?

P.S I am not a Petrolhead or mechanically minded, I just love my Morgan!

Have you tried a longer top alternator bracket to try and pivot the alternator as far from the engine/exhaust as possible? Obviously you would need a longer fan belt.

Or you could try one of the WOSP style denso alternators which tend to have a shorter body.

I have the earlier Kent derivative in my Mog, but have had no issues with the alternator.

There should be a heat shield between the alternator and the exhaust, At least my 4/4 has.
Never had a problem with it. I had to replace it a few years ago because the bearings started to make noise.
Not abnormal after more than 25 years of intensive use.

I have a heat shield on my 4/4 .not had any problem .

Good luck finding a solution John although I would hesitate to blame overheating from an external source. An alternator working hard will get quite hot in it's own right, but check it's integral cooling fan is spinning the correct way, typically drawing cool air in from the front.

Just for the record though when your alternator "output" drops to 12.7 volts (= fully charged battery) or below, with engine above idle, it's faulty and producing NO output at all, you are simply measuring the battery voltage to which it's directly connected.

Although my first port of call would be heat shield, I would also ask: How old is your battery? I am a bit suspicious of your <12 volts measurement, as a reasonable battery should give >12volts without help from the alternator . It is possible that there is an internal short in the battery, maybe due to buckled or sulphated plates which places an additional load on the alternator. If you still have the same battery since you bought the car, there is nothing lost in renewing it anyway as it would now be past its useful life.

Cannot have a look (for a heat shield) now because our 4/4 is stored at another place at this moment, but we never experienced any difficulties with our 4/4 4-seater 1990 CVH in 27 years of ownership and intensive use!

Ultimate solution would be to use a small Nippon Denso/Kubota self regulated alternator which is very compact - this is what I did on my TR4 engined Plus 4 due to clearance issues with the tubular manifold.

Are you using a new alternator or a recon alternator? Some of the new ones on the market are a bit questionable in terms of quality control so I prefer to have an original rebuilt.

Arwyn