OK guys in my earlier post and thanks to all the good advice I found that my headlight control module is bad as seen below.





I find that the little fuse link F1 and F2 on the board was melted to both of the transistors and one of the transistors is burnt.

I saw where our administrator Cliff Pennock had the same problem and he repaired his controller board and from the pictures it looks to have been the same transistor as mine that was lost.

My question is, do these transistors fail due to age or has something else shorted them out causing it to take out the transistor?
Reason being, I also notice that my right headlight motor needs to be rebuilt because it's jerky-jerky and falls back down. I am wondering did maybe this motor take out the transistor because it never reached the amperage draw to turn off the motor and it just kept running and running thus causing the transistor to heat up and fail? Just a thought, but my gut feeling is they just failed as with any other aging electronics.

Other than a few resistors and a few diodes, and of course a relay, there is a IC chip of some sort, I can only assume it's still in working order.

I am by no means any kind of an authority on knowing the ends and outs of circuit boards, but I will usually try repair /replace the parts that are bad provided if I know what to look for and from the looks of this board this might be something I can handle...MAYBE!

I will go ahead and replace both if these parts, will I be able to get the same ones with the same numbers or is there a new number for these two transistors?

John

EDIT: strike that idea out about the motors over running the cave just told me how it has a time circuit.....hum I bet the IC chip has something to do with that!

[This message has been edited by John N (edited 11-08-2010).]

Controller usually doesn't fail.

Cliff module got wet...
You have a bigger problem...

You have a least 3 issues...

Bad MOSFET
Bad Fuse (F1 & F2)
Bad solder joint on backside.

And just quick scan for me... Maybe more after I sleep...


Red line slowed obvious "cold" solder joint. Check all joints...

Can you fix it? maybe.
I recommend you get a good use module. parts are link in cave item.
Check used module for bad solder joint, same as above. Easier to fix joint now if any...

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 11-08-2010).]

quote Originally posted by theogre: Controller usually doesn't fail. Cliff module got wet... You have a bigger problem... You have a least 3 issues... Bad MOSFET Bad Fuse (F1 & F2) Bad solder joint on backside. And just quick scan for me... Maybe more after I sleep... Red line slowed obvious "cold" solder joint. Check all joints... Can you fix it? maybe. I recommend you get a good use module. parts are link in cave item. Check used module for bad solder joint, same as above. Easier to fix joint now if any...

Thanks for that information and not to sound really stupid, but what is a MOSFET and where is this item located?

I will check out your links on just findiing another one.

Thanks again, John

MOSFET = burn "transistor"


------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 08-30-2011).]

If you do decide to get a new module, get one from the link I have here. http://www.top-downsolution....php?products_id=119 There a lot cheaper than the fiero stores. I bought one for my 88 and it works great.

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Adam

quote Originally posted by ANAM427: If you do decide to get a new module, get one from the link I have here. http://www.top-downsolution....php?products_id=119 There a lot cheaper than the fiero stores. I bought one for my 88 and it works great.

Yeah Adam, that was the first placed the popped up last night when I Googled for this module...Priced right too! Most likely I will do as Orge suggested and just get a different one, I have so many other problems with this car.

I am now starting to wonder if maybe I should have passed on buying this Fiero, but the price was good and the undercarriage was in such good shape. I suppose I shouldn't be to surprised of all of this with a 23 year old car that has been sitting for a few years, things are bound to be bad.

I guess time will tell!

John

I've gone through a few of these modules myself after owning a number of '87s and an '88. I've opted to just replace them with spares in the past, but, as they all get older, they all seem to fail. I'm going to look into sources for each of the components. Looks like other threads have covered the relay. Not sure if anyone has taken the time to list the transistor/MOSFET part number, but, I'll look for that and see if we can either collect all of the parts in this thread or start a new one with them all. Does anyone have the specs for the fuse link? I can't seem to find that anywhere. For older modules and testing, does it make sense to replace these with a socket and a more standard replaceable fuse?

P.S. Cliff mentioned part # IRF540N in this thread //www.fiero.nl/forum/Forum2/HTML/095675.html

The Module is the same GM used in all their later style pop up headlights right up to the C6 Corvette. I picked one up for 20 dollars from a 97 Vette from the local Corvette parts dude. It has the exact same part number as the Fiero.

Follow up post:

I found a control module on eBay off of another car for 10 bucks. However when I installed it, the motors would not shut off and it ended up being the delrin pins were disintegrated due to age. I ordered new rebuild kits with gears and gaskets and installed them and everything is working fine.

What I suspect is maybe the PO turned on the lights and since the pins were disintegrated they would not fully open up since the gears were slipping and therefore they would keep trying to get them open up by turning them on and off over and over again, thus overheating the module components and blowing the fuses and transistors.

I have the old control module and will keep it with plans on replacing the bad parts.

I think having a snap in type fuse might be a good idea and I have seen some small fuse holders that might just work.

I do know that I like these headlight motors a heck of a lot better than on my 84 and if I keep the 84 I will switch them over to the second generation motors.

Thanks for posting that update. I'm in a similar situation with an 88 Formula that I just picked up. I started by replacing the actuators and I know the gears in the new ones are good, but there is no power coming through the original connectors (checked with my multimeter).

I found that the previous owner(s) had some electrical work done where a live wire was used to bypass the module...at least I think this is what they were trying to do. I'm planning on taking a peek under the left wheel well to see if they did and will check out the module to see if that is bad.

[This message has been edited by Norb_88Fiero (edited 03-29-2011).]

.... nm

[This message has been edited by theogre (edited 04-22-2011).]

If you want to rebuild the module in that first post, you'll have to make a new board first, the traces on the lower right appear to be damaged. All those parts look easily identifiable/replaceable, except for the integrated circuit, but you could carefully desolder it, and solder a socket to the new board and plug it in.