Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Alternator for series 1 roadster

Reckon I need a new alternator for my roadster. Got around to purchasing a multimeter today and checked the charge with the engine running. 13.5v.
As the engine is from an ST220, will an ST220 alternator be the same, or will it be different?

Is it a simple enough job to replace? TIA

Never had one off. Simon said belt changing is tough because adjustment is negligible. Removal looks tight, but everything is possible.

Don't assume it's ST220. Cross check with Jaguar X type and S type. There will be a part number on it somewhere. I'm not at home, or I would look.

If you haven't made a heat shield, make one up for the replacement because the exhaust manifold is only a few mm away.

I haven't got a heat shield, so guess that's my next project. Never have problems with charging but checked as I thought it could be related to my ever so slightly rough idle. Guess once that's sorted I can tick that off the list if it's not the problem.

GoMog reckons it is
Alternator: Mitsubishi A005TA7792. I am told but do not know for sure this crosses to 2001-08 Ford Fiesta and also in some Mazda Z Techs.

But I would advise checking the label.

13.5 volts into the battery is low but remember the alternator is only regulated to give a maximum of 14.4 volts or thereabouts. To a large degree the battery itself dictates the voltage and only reaches alternator regulated voltage when close to being fully charged and with engine well above idle. Given a depleted battery it may take some time to reach this voltage especially in the winter with lighting, wipers, heated seats etc. to contend with.

Worth checking this out before replacing alternator. Ensure battery fully charged then at the end of a good run check battery volts with an accurate voltmeter and engine running at least 2000 rpm.

Completely endorse Richard’s comments. 13.5 to 14.5 is to be expected, depending on rpm and state of battery.

I had been out earlier today, and the battery put back on its charger so it would have been full. Would 13.5v normal at idle? Engine was still a bit warm.

As long as battery volts rise significantly when engine taken well above idle Leroy, I would think all is well.

Thanks Richard, as always. Will check this out tomorrow.and update.

I've just had the alternator voltage on my 2005 series 1 Roadster tested and it's giving 13.9 volts.