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Lucas Alternator Question

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RobT

RobT

Jedi Warrior
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My alternator is on the fritz. Its the one for the Europa, but thought I'd ask here as the Lotus forum is pretty quiet.

Anyway nothing seems to be open circuit, but the alternator is not charging. Its a Lucas ACR, not sure the model - has a "1" followed by a vertical "5 6 7" and "ACR" on the back. Four wire hookup - 2 field and 2 power by the looks.

Could be just the rectifier and/or brushes which are looking all pretty corroded etc. Anyway does anyone know the best way to trouble-shoot these alternators? Are parts (brush set & rectifier) still available? Any good rebuilders in New England/East Coast? Or should I just throw in a modern replacement?

TIA

Rob.

BTW Really nice "British Car Day" in Brookline, MA today. Some lovely cars - real jaw-dropping stuff. And got to meet Paul Rego (Brosky) too.
 
The biggest problem we find here at work with the Lucas alternators is the brushes/rotors, followed by rectifiers. Since you mentioned two field connections, that means that the charging system has a seperate voltage regulator. Take an ohm meter and place it across the field terminals. If you get no continuity, then either the brushes are worn down, or more likely the rotor has an open in it. You should be able to take the brusholder off the back to get a direct connection onto the rotor slip ring to check continuity. Brushes are easy to get, but rotors have to come from cores.
 
If you are more into driving then showing, then I would store the Lucas unit (for the purist) and upgrade to a modern unit. Just one less thing to worry about...
 
"ACR" models have internal regulators, which appear to be a common failure point. They can be distinguished from the externally regulated "AC" models (like your TR250) by the black plastic cover on the back (over the regulator module).

ACR models do typically have 2 (or more) small terminals; one is a voltage sense wire and the other is the connection to the warning lamp on the dash.

Don't know about ACR brushes, but the regulator modules are frequently sold on eBay.

If it uses a main connection like shown in the attached file, then one alternative is the Bosch alternator used on a 78 Ford Fiesta with AC. (Non-AC models used a Motorcraft alt that is completely different.) The Bosch will bolt right up, use the same pulley and plug. And while not completely identical, it looks very similar to the Lucas. I forget the max current rating offhand, but it's substantially higher than the Lucas, and puts out a lot more current at idle.
 
Rob,

I was a pleasure to meet you and your lovely family today as well.

I have used these guys for alternators and starters for years. I say that because they did a lot of work fro me when I was in the business and they've done both the starter and alternator on my TR6. Great prices and service too!

They have a lot of parts for these and do everything in house, so he can turn it around very quickly for you.

Yankee Auto Electric Repair
156 Division Street
Pawtucket, RI 02860
401-726-0291

Ask for Brad and tell him that I told you to call and you're a friend from the British Car Club.

BTW, You left early, but I did win First Place for all Triumph's today.
 
"I did win First Place for all Triumph's today."

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Way to go Paul!!! Well earned.

d /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
Thanks Dale. I had a great time and it would have been worth it even if I had won nothing. Great weather and nice people and a lot of car talk all day long. Rob can attest to that.

I hope to have some pics of the exotic stuff up soon.
 
Rob
wot Randal says. For some reason my regulator keeps failing on my Lucas alternator.
Every Triumph enthusiast I speak to says upgrade to a Bosch 55a unit and never have probs again.
Regards
Craig
 
Thanks for the advice. Someone sent me a link to the Lucas workshop manual:

https://lotus-europa.com/docs.html#electrical

So although I'll probably regret it, I'm going to attempt a rebuild myself. Its about $50 in parts so worth the chance. And I might learn something on the way. If it fails again - I'll go with the Bosch!

Paul - congrats on the first place! There was some tough competition too. Did you see the guy with the TR6, who bought his own tent (for the car)? Thought that was a bit over-the-top.

I have to say the MOT in Brookline put on a really good car show. They even had a "Where's Waldo?" competition for the kids (which our girls - ages 7 and 10) loved. They had planted about 20 little Waldo figures in the exhibits and concessions, and if the kids found 14 they got a prize (a post card of a vintage car). Kept them amused while daddy got to look at the pretty cars! Great idea.

Rob.
 
Well I used to think I was indecisive - but now I'm not so sure.

I ended up both finding a used Ford Fiesta alternator (55A with integral rectifier - I hope that's the right one), and sending my Lucas unit to Yankee Auto Electric.

Spoke to Brad there - he was very helpful. Mentioned Paul's name, I'm sure that helped too. Thanks for the recommendation, I'll let you know how it turns out.

Rob.
 
RobT said:
Well I used to think I was indecisive - but now I'm not so sure.

I ended up both finding a used Ford Fiesta alternator (55A with integral rectifier - I hope that's the right one), and sending my Lucas unit to Yankee Auto Electric....

Rob.
Click to expand...

Not indecisive, just an experience British car owner. We all know that the spare on the shelf will soon be in the car...
 
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