quote Originally posted by Marvin McInnis: For those who don't like the diode solution, I will soon post a circuit that uses a single relay to perform the same function.

Marvin, is there any concern in regards to overloading the circuit with all four lights being lit when high beams are on?

quote Originally posted by topcat: Marvin, is there any concern in regards to overloading the circuit with all four lights being lit when high beams are on?

I have employed the diode circuit successfully in other cars with halogen headlights (e.g. Porsche 911 and 928), but not (yet) in a Fiero.

The schematic in the GM/Helm factory service manual (FSM) indicates that the size of the wiring downstream of the headlight switch is 1 mm, which corresponds to 16 AWG. The FSM also shows that GM specifies 25 amp fuses to protect circuits using 1 mm/16 AWG wires, but it does not indicate the current rating of either the headlight switch or the dimmer switch. In aircraft practice (per FAA EA-AC 43.13-1A), the maximum current rating of 16 AWG wire in free air is 22 amps continuous, 26 amps intermittent ... both limits due to wire heating. Since each headlamp draws about 5 amps (x4 = 20 amps total), the stock Fiero wiring is thus marginal, but it should probably be OK. The closer the diode is connected to the dimmer switch, the better it will be.

A second consideration is the trip rating of the circuit breaker built into the GM headlight switch. It is possible that the breaker may trip after a long period of operation with all four headlights illuminated. Even though the breaker is self resetting, this is not a good thing to have happen when cruising on a dark road at 75 mph!

The relay circuit I plan to post will avoid both of these potential problems.


Edit: Forget the diodes, you don't need them. See my later post on page 3 of this thread.

[This message has been edited by Marvin McInnis (edited 08-20-2008).]

(rubbing hands together) I can hardly wait........ I have already ordered my diodes......please tell me I didn't buy them for nothing!!

Marvin, do yo have a direct link to the diode on the website that you use... or a part number? I want to make sure to get the right one. Since I've never orderd a diode before, I am not familiar with the language the websites use. Does Radio Shack carry them?

quote Originally posted by topcat: Marvin, do yo have a direct link to the diode on the website that you use... or a part number?

Here are the SKUs of several (of many) diodes that should work and are currently available from stock at DigiKey. The links I've provided reflect real-time price and stock level information, but they may not work in the future. In that case, just do a search on the SKU number.

CC1361-ND: 15 amp, 400 volt, isolated-tab TO-220 package ... @ $1.84
CC1365-ND: 20 amp, 400 volt, isolated-tab TO-220 package ... @ $1.71
CC1369-ND: 25 amp, 400 volt, isolated-tab TO-220 package ... @ $1.98

"Isolated-tab" indicates that the mounting tab is electrically insulated from both terminals, which means that you can just (carefully) bolt it to any convenient flat sheet metal surface for use as a heat sink.

quote Does Radio Shack carry them?

You can try Radio Shack, but I doubt that they will have what you need ... or even understand what you're asking for. It seems that all most Radio Shack stores want to sell any more is cell phones and electronic toys.


Edit: Forget the diodes, you don't need them. See my later post on page 3 of this thread.

[This message has been edited by Marvin McInnis (edited 08-20-2008).]

Just bumping to the top for anyone else that might want to get in on the group buy.

quote Originally posted by topcat: Okay, here are the details: The supplier will get us four lights (2 low and 2 high beams) for a total of $221.50 shipped. Since I really do not want to be a middle man and have them sent to me then have to turn around and ship them out, nor do I want to handle anyone's hard earned cash, he agreed to take phone orders directly from folks calling from PFF and indicating they are in on the group buy. So what I need is for each person that wanted in to PM me with their full name. Once I get that info I will call Will and give him the names, and when you call in he will give you the group buy price. Each light comes with all mounting hardware that you need minus the electrical connector. I had some ask for connectors. He will also give connectors at a discount, so if you want the connectors, add $24.12 to the total. Shipping is via UPS ground. We really need at least 20 total lights to be sold, so we need at least 5 of those that said they wanted in to pony up. PM me with your info please.

As promised, here are two relay circuits that will keep the low beams lighted when the high beams are on. Although they lack the elegant simplicity of the diode circuit posted earlier, both of these circuits will remove any remaining concern about overloading either the factory wiring or the breaker in the headlight switch. These circuits are also designed so that a blown fuse or failed relay won't leave you without headlights; the system will just revert to "normal" operation.

The first circuit activates the relay only when the high beams are on. This circuit can be used when halogen low beam bulbs are installed, but do not use it if you have HID low beams. The relay contacts will probably have a slightly shorter service life with this circuit, since they open and close every time you switch between low and high beams.




The second circuit keeps the relay activated whenever the headlights are on, regardless of whether low beams or high high beams are selected. This circuit can be used with halogen low beam bulbs, but it must be used if you have HID low beams. The relay contacts will probably last longer (due to fewer open/close cycles), but balanced against that the relay coil will be powered the entire time the headlights are on.

Note that the only differences between this circuit and the previous one are 1) the connection to the relay coil is changed, and 2) the low beam circuit is disconnected from the dimmer switch.



Remember ... since these are DC circuits, you can make the physical connections anywhere along the wires. (You don't have to make the connections exactly where I show them.) In both of these circuits, you could make the +12 volt "hot at all times" connection near the headlight switch (in the instrument cluster) or use one of the spare BAT terminals on the fuse block, make the other two connections near the dimmer switch (on the steering column), and mount the relay somewhere under the dash. And don't forget the ground connection, which can be located just about anywhere.

The fuse is there to protect the wire from overheating in case of a short, so select a fuse to match the size of wire you use (e.g. a 25 amp fuse if you use 1 mm/16 AWG wire) and locate the fuse as close as possible to the +12 volt "hot at all times" bus connection. Finally, select a relay with a 12 volt DC coil, and the contacts should be rated for 20 amps (or higher) at 12 volts DC (or higher); the contacts must be rated for DC operation.

Susquehanna Motor Sports sells a suitable relay kit (item number HL26000, currently priced at $12.83) that includes a 40 amp relay, a relay socket, and a fuse holder.

I hope this helps. And, oh ... not to be cranky ... but these schematics come with a "big boy" warranty. All the information you need is there. If you can't read and understand them, then you should probably have somebody else help you with the wiring.


Edit: Forget the diodes, you don't need them. See my later post on page 3 of this thread.

[This message has been edited by Marvin McInnis (edited 08-20-2008).]

quote Originally posted by topcat: Just bumping to the top for anyone else that might want to get in on the group buy.

I called Will at SMS today and ordered my lights and connectors, so I am part of the group buy topcat !!

He told me that I'm #4 so far, so figure that into your minimum for the discount, (Will gave me 10% off)
I thought I was too late to get in on your group buy so I called SMS and when I mentioned Fiero he automatically asked if I was one of the PFF group....so I said SURE!

Randy

Glad you were able to get in on it. He did tell me he'd leave it open for about a week, so there is still time for others to jump in on it.

quote Originally posted by randye: I called Will at SMS today and ordered my lights and connectors, so I am part of the group buy topcat !! He told me that I'm #4 so far, so figure that into your minimum for the discount, (Will gave me 10% off) I thought I was too late to get in on your group buy so I called SMS and when I mentioned Fiero he automatically asked if I was one of the PFF group....so I said SURE! Randy

Ordered mine today so I guess that makes me #5 Your friend Will was very helpful too... if I ever need a set of lights again I'll be sure to look him up.

quote Originally posted by Leeloo88: Ordered mine today so I guess that makes me #5 Your friend Will was very helpful too... if I ever need a set of lights again I'll be sure to look him up.

Great, and I actually think you were either number 6 or 7, so we met the terms of the group buy. Thanks to all... and for the record, I do not know Will, I sent Susquehanna Motor Sports (SMS) an email asking if they were interested, and Will was more than helpful, and as indicated earlier, he did say he'd keep it open for approx a week. If there are others that are interested, give SMS a call and ask if you can get in on the PFF group buy. It was not a HUGE savings, but it was a little savings none the less.

Cheers~

when i call (hopefully i get home early enough tommorrow) will i need the part numbers or will he already know?

You can just tell him you're part of the buy. He already knows what we're ordering. You just have to decide if you want to get the connectors as well.

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I'm in. Just got off the phone with the guys. Great guys to talk to! I had actually called to order, and the first guy I talked to forgot to give me the figure with the discount. No problem at all, I just noticed, the price was a little higher, after I hung up. Well, I called back, and got Will, and he had already corrected the situation. Like I said, very easy to talk to, and no hassle. Was told, they sold like three sets just this morning, which wiped them out, but more are on the way, and should arrive in a couple of days.

Kevin

Yep, SMS runs a first class operation. They sold 8 sets at the group buy price. If there are others that want lights, give them a call. They might still honor it since he did say he'd keep it open for a week.

I can hardly wait to get my buckets and lights.
Thanks again to everyone that participated

Will was also offering the discount, to most any item on the site, except for a few things like tires, and I can't remember the other two or three things. I don't remember the details, just give them a call if you need anything else.
I added a set of Hella 450 driving lights to my order.
Kevin

My lights came in today... now the wait for the buckets.

Go my lights today, Beautiful! Just waiting for the rest of my refund so i can get the buckets

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www.FieroDomain.com
Over 120 Fiero Links, Articles, Images, Diagnostics

"If any car is both the parade and the rain, it is the Fiero"

Sure, I leave for holidays and this group buy happens. I assume it's too late to get in on this?

Thanks
Nolan

quote Originally posted by Sourmug: Sure, I leave for holidays and this group buy happens. I assume it's too late to get in on this? Thanks Nolan

Nolan, give SMS a call at 610-944-3233 and ask for Will. They might still honor the discount. They are open until 7:00pm.

With the next round of buckets getting close to shipping is he willing to arrange a second group buy?

When I called for the first round, he wanted at least 20 total lights sold to give us the group buy, so the question would have to be, How many folks are interested in another round?

im interested in this ill need a little bit to come up with the $ but if others want in count me.

20 total lights sold or 20 total kits sold?

20 lights = 5 people, that is easily done. I am in on this next round.

anyone know if they sell the connector to go into the Fiero light socket to make the harness as well? I could not find it on their site.

[This message has been edited by timgray (edited 03-16-2007).]

I'd be interested if there's another group buy. Procrastinated long enough.

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario
'84 Indy

quote Originally posted by timgray: anyone know if they sell the connector to go into the Fiero light socket to make the harness as well? I could not find it on their site.

Susquehanna Motor Sports: H4 male plug, item number HL28000, $5 each.

[This message has been edited by Marvin McInnis (edited 04-11-2007).]

quote Originally posted by whadeduck: I'd be interested if there's another group buy. Procrastinated long enough.

LOL, you and me both!

Nolan

I'm interested in the second group buy

I am also interested

I tried to stop procrastinating so much one time, but I kept puting it off.

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario
'84 Indy

Add me to the Group Buy
Just Called SMS and ordered, so use me as one more for the list.

[This message has been edited by DrDave (edited 04-11-2007).]

quote Originally posted by DrDave: Add me to the Group Buy Just Called SMS and ordered, so use me as one more for the list.

Did you call and ask for the Fiero group buy?

if so then they are still honoring the original group buy. Please let me know, and if not I can see about setting it up again.

Cheers

I'll see if I can call them tomorrow if I get a lunch break.

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario
'84 Indy

I just ordered a set of the 90mm headlamps via telephone. They are still honoring the group discount (10%). But apparently they're out of stock, and have a new shipment coming later this week.

is this group buy deal still going on?

If its still going on, I could possibly be interested as well....

I will buy a set also if the deal is still available!

I bought mine about a month ago and they still honored the discounted rate.

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Whade' "The Duck Formerly Known As Wade" Duck
'87 GT Auto
'88 Ferrario
'84 Indy

Thanks, I will give it a try in the morning

There should be some way I can get in on this ........ after all I have brought them a lot of business!! j/k Maybe I should send Hella an email asking for part of the profits?!?!