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MG TD TF 1500 - TD /Halogen Headlamps

I have an original, later model Lucas 19 amp generator on my TD. I installed some halogen headlamps which apparently draw far more current than I expected because with them ON, the ammeter indicates a discharge at driving speeds. I have been advised not to incrase the current in the regulator for fear of cooking the generator. What experience have others found using the halobens?
Jim Merz

Jim,
I don't know anything about halogens but I'd take them off.

Warmly,

Dick Thomas
TD13583
Dick Thomas

I used halogens on my 54 TF for four years without any problem. I did not however do much extended nightime driving beyond two hour or so at a time. The battery stood up to the slight overdraw with zero complaints.
Sandy
conrad sanders

Jim - If you have a multimeter that has a 10 or 20 amp range on it, hook one of the lights up in series with the multimeter and see what each filament draws. Multiply that figure for each filament by 2 and you will have a current requirement for for the headlights. If the combined current draw is greater than 19 amps, then the battery will be supplying that extra current and will therefore show a discharge on the ammeter. you can run for a considerable distance with a small discharge on the battery before it drops the voltage too far down for the car to run, but you will need to hook up a battery tender overnight to recondition the battery or you may not be able to start the car the next morning (I hook our TD up to a battery tender every night because I have an 8 year old battery in it that is a bit tired).

I agree with whoever told you not to increase the with the regulator. Bob Jeffers sets his solid state regulators so that the maximum current that a generator is rated for cannot be exceeded for the same reason - you don't want to cook the generator. Cheers - Dave
David DuBois

Jim,

While they are not individual bulbs, I have been using the Sylvania Silver Star sealed beams, and I can speak volumes for them.

I will admit that I won't use them on high beam unless I am running at 3,000 RPM or greater, but nonetheless, I find them just perfect for the TF.

Gord Clark
Rockburn, Qué.
Gordon A. Clark

Gordon - I checked the Silver Stars and they don't draw any more current than the standard sealed beam halagons that have been on the market for years. Cheers - Dave
David DuBois

Dave -- You forgot to mention the draw of the ignition. On my TD car that is 4 amps which would only leave 15 amps for everything else.

Jim -- Get a clip-on DC ammeter and see what the output of your generator is. My guess is that it is not 19 Amps.There is a 3/4 turn coil on the regulator relay between the A and A1 terminals that is supposed to up the voltage at high outputs but I have found that it really dose not help. If you can lay hands on one the "spriget" generators were rated at 22 Amps and did have the tach drive output. Also the replacement generators Moss is selling are supposedly rated at 22 Amps. Holcombe Armature also told me their armatures will stand 22 Amps.

Cheers,

Bob
R. K. (Bob) Jeffers

Jim,

My sealed beam halogens are 60 watts on bright, at 12 Vdc this would be 5 amps each, or 10 amps.

Bob, do you know the part number for the Spridget generator? I think I have one on my car, it has spade terminals and a slightly different cooling disc. The number on my generator is 22744 E 12V C40 with a date of 5 68.

warmly,
dave


Dave Braun

Dave -- The C40 case is an indication that you have a 22 Amp generator. MY Lucas information does not extend much beyond 1958. The real identifier is the 22744 number. Seems to me one of our regular contributors had Lucas information up into the seventies.

Larry Karpman maybe?

Sorry I can't be more helpful.

Bob
R. K. (Bob) Jeffers

Very helpful Bob. Yippee! I'm running 15.8% more juice. I'm glad I kept the unit rather than locate a more 'original' one. It will take a pretty sharp eye to spot the difference. I never did until I got my new wiring harness... well, I always knew my cooling disc was different, but no one else ever said anything.

One additional questions:

Where would one connect the clip on DC ammeter to read the output on our generators? (I am leary of generating a generator killing spark).

warmly,
dave
Dave Braun

I got sealed beam halogens from Moss for my TD. I checked at the time and I think that they were around 30 watts (which I think is almost the same as the stock bulbs).

They are made by Warner I think, and they work great. I can see FAR better, and the anmeter on my stock electrical system shows a positive charge when driving. I highly recommend them. I did find after I put a new wiring harness in that the high beams were much brighter, but I think I had the original harness.

They were also very inexpensive ($11 ? comes to mind). I don't think you can get them much cheaper elsewhere.

Larry Ayres
Larry Ayres

It seems that most of my halogen problem is with the individual bulbs I am using rather than a completely sealed beam unit. As an old geezer, I need all the light I can get. Maybe a swap for the sealed beams is in order.
Jim Merz

Seems to me that you have the wrong halogen bulbs. Anthony Pearson in Australia makes halogen bulbs for our cars. Google Classic and Vintage Bulbs. As I recall the original wattage for the tungnsten bulb was 35W. Anthony makes halogen bulbs that fit in 35W and they are twice as bright as the originals. I have them in my YT and TC and there is no negative battery drain. Terry
Terry O'Brien

When I first got the TD on the road, it had 60/50 bulbs... they were perfectly round (Lucas BPF lamps). The only thing they had on them was the name 'ROYAL'... I'm told this was a Lucas company(?)
These were the best lights I have ever had on 'any' car, including modern ones. When one blew, I ordered bulbs from England 50/40 and they are ok, but nothing like the royals. Have searched for them ever since the 2nd one blew. (tried the 35/35's and can't see anything)
gblawson(gordon)

Dave B. -- You clip the ammeter on the wire from the larger terminal. If it reads negative turn it over. In this position it will read the total current that the generator is putting out including the ignition requirement but not the field current. That is OK because the generator ratings take that into account.
Cheers,

Bob
R. K. (Bob) Jeffers

Dave DuBois,
If a halogen bulb and a sealed beam are both rated at the same number of watts and voltage, won't they draw the same amount of current? Or is more of a brightness rating? I'm confused.
Jim Merz

Jim, the current will be the same if the watts and voltage are the same. However, the halogen lamp will burn at a higher temperature and will be more efficient in terms of light (lumens) per watt. The 'brightness' of a sealed beam halogen lamp may be different from that of a lamp (reflector/lens) with a separate halogen bulb. The optics involved can make a big difference in how the lamp illuminates the roadway.

I'd be happy to loan you my clip-on DC ammeter to make your tests. Just let me know. Bud
Bud Krueger

Bud, is there any such thing as a cheap DC ammeter? I was looking at some on line today and for the few times I would need one, I will hold off buying my own for a while. Thanks for the offer though. The simple fix for now is to go back to my old sealed beams.
Jim Merz

Jim,

Here's an affordable multimeter with a 20 amp DC range - http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=37772. Note, it comes with a temperature probe also, just in time for barbecue season. :)

Bob
Bob Farnam

Bob,

This is the type of ammeter which Bob Jeffers is talking about.

http://www.gossenmetrawatt.com/english/produkte/metraclip70.htm

warmly,
dave
Dave Braun

Thanks for the inputs guys. I bought a clamp-on meter from Harbor Freight but it will not read DC amps! Now I find that there are such things. I'll wait until I receive the info Bob Jeffers has so generously offered for a home-made version to make any decisions. A 20 amp device would certainly be a step in the right direction.
Jim Merz

This thread was discussed between 08/07/2008 and 13/07/2008

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