Hi, Guys,

As you all probably know, Fiero Power Windows do not use relays and pass full operating current through the window switches. Frequently our slow windows are a result of losses in those switches.

It appears that it will require two relays per window: one DPDT and one SPST. The existing circuit uses a single 30 amp circuit breaker to protect both the windows and the power locks. Therefore each window must draw something less than half that or 15 amps at stall.

There are some very inexpensive 5 amp dpdt relays available on Amazon.

Has anyopne actually measured the stall current on one of the windows?

There is also a circuit breaker on each of the window motors, but I cannot seem to find the spec for that in the FSM.

Any help would be greatly appreciated.

TIA,
Larry

i am looking to do the same thing before i move onto fitting newer motors from a truckor something with heavy windows.

i was just going to use a Normally Open relay inline with the power window wires from the switch to energize the relay coil and a full 12v strait from the battery to a new distribution block then to the windows themselves.



i cant draw a text schem like i thought i could, so i drew it and took a picture with my iphone and so on

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First LX9 Fiero GT, 1987 | My Fiero Fuel Economy | MPG Display for OBD I
Youtube Videos of My GT | modernize your fiero with technology!
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
screw paying those bastards. im not going to become rich by paying for things.....

[This message has been edited by americasfuture2k (edited 04-20-2010).]

americasfuture2k,

That looks like it would work...if you only want to raise OR lower the window. I believe you must reverse ground and 12v to the motor terminals depending on whether you are raising or lowering the window: thus one needs a DPDT relay controlled by the window switch to select up or down, and then a SPST relay to kill power to the motor when one has raised or lowered it.

See schematic on page 8A-120-0 of the '88 FSM.

Larry

have you considered rummaging through a bone yard looking at existing cars with power windows. It just seems that the relays you need might exist somewhere there.

My1stMidEng,

I would love to, but, so far as I know (I am a transplant), there are no yards where one can pick through or pull anything at all.

Last thing I bought from a yard was the cigar lighter plate/ALDL cover and they would not even let me look at it until they had pulled it!

Larry

ah yes, i forgot to list that. get the pwer windows relay from a scrapyard. i have a bag full of them from everytime i go. that was just a quick rough sketch relay i drew up, of course it would need to be a DPDT to work up AND down.

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First LX9 Fiero GT, 1987 | My Fiero Fuel Economy | MPG Display for OBD I
Youtube Videos of My GT | modernize your fiero with technology!
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
screw paying those bastards. im not going to become rich by paying for things.....

I think Dickman's product works the same way http://rodneydickman.com/ca...h=21&products_id=271

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My World of Wheels Winners (Click on links below)

3.4L Supercharged 87 GT and Super Duty 4 Indy #163

fierosound,

Yep, I believe Rodney's work just like that....although he has added MOV's to minimize arcing. But at $39 per side (with shipping), I think I can do better....5 amp relays can be had for as little as $1.50, MOV's for about $5.00....yes 5 amps is on the light side, but they only operate a few seconds at a time and even if they fail fairly quickly, I can always replace for $1.50.

Thanks for the reminder about Rodney's product, though.

Larry

If the Motor stalls, the motor draws in excess of 12 Amps. But that current varies, depending on battery voltage, engine runnung, mechanical condition, etc. I have seen it exceed 15 amps at stall - remember the circuit breaker usually doesn't trigger because you rarely stall both motors at the same time.
But even with the window going up smoothly current draw is 6-8 amps. 5amp relay is going to fail sooner or later.

Best regards

Oliver

keep us updated on how well this works. measure the voltage at the battery and at the window motor.

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First LX9 Fiero GT, 1987 | My Fiero Fuel Economy | MPG Display for OBD I
Youtube Videos of My GT | modernize your fiero with technology!
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
screw paying those bastards. im not going to become rich by paying for things.....

[This message has been edited by americasfuture2k (edited 04-21-2010).]

quote Originally posted by imacflier: fierosound, Yep, I believe Rodney's work just like that....although he has added MOV's to minimize arcing. But at $39 per side (with shipping), I think I can do better....5 amp relays can be had for as little as $1.50, MOV's for about $5.00....yes 5 amps is on the light side, but they only operate a few seconds at a time and even if they fail fairly quickly, I can always replace for $1.50. Thanks for the reminder about Rodney's product, though. Larry

I am like you in a way, I think I can do things a little different at a better price. BUT, on thins one I would spend the money at Dickmans. I installed a set in about a half hour and they worked outstanding. I would have spent $20 (everything in CA must be made of GOLD) at the yard for a hand full of pits and pieces and then my time which could have been 2-3 hours easy. Then the wire splicing from relay to relay and finding a good place for the four relays ( one up and one down per side)? Then if you don't get the properly rated AMP relays your work is going to be wasted.
I was a sceptic of the Rod relays, but not anymore. They are a GREAT upgrade and very easy to install.

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[IMG][/IMG]

My relay kits have 4 relays in each unit. The EE that designed it told me this is a better way for some reason. 2 will work. I may have that in an email. I would have to search. But I think he told me this verbally and I can't remember now why. He is also a Mensa(?) person. A very smart guy. So mine cost more because of there being 4 relays in each.

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Rodney Dickman

Fiero Parts And Acc's Web Page:
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Rodney Dickman's Fiero accessories
7604 Treeview Drive
Caledonia, WI 53108
Phone/Fax (262) 835-9575