TheoUK and Skeets

What year cars do you have? I've had this prob for ages on my 78, but I know th welater cars are different (with the module in the rear box etc). Sounds like I might need to make a trip up north!

Ta!

 

Hi Stephen.
I spoke to you about this ages ago - and i still haven't got off my ar$e to sort it out! Mine's an 80. I've heard the early ones are different. I bet the route to fixing them is very similar. What's yours actually doing (or not doing)?
Have you got any photos of your cotrol board? Might help to see how similar they are between years, ie if there's a big transistor that's expected to take a stupidly high power etc etc.

If you want to make a trip up north, then feel free, but remember - its grim up here! :cheers:

 

Hey Geaxcat,

My windshield washer actually does work, believe it or not. The only thing on my Vette not functioning is, of course, the clock and this interrmittent wiper deal. I am hoping to get that fixed so the clock will get nervous and see that I mean business. Then, maybe, it will start to work on it's own out of fear of being fixed or replaced.




[Modified by CVT4ME, 8:43 AM 10/13/2003]

 

Yep theo, i did replace the thing with the huge aluminum bracket clipped to it!

I'm not sure what the rating of the replacement was.. i just gave it to someone and said please make it work! ... though i will check and let you know. I seem to remember that my original was a texas instruments item too ... my car is a little earlier (79.. to answer stephen's question.. hi stephen).. and my control board is on the transmission tunnel, but i would guess it is exactly the same as yours.

I was planning to just take the board to an electronic components shop and ask for "a bigger one of those please" ... though i have to find somewhere that sells that sort of thing... i guess maplins or somewhere like that?? ... Though you seem to know rather more about electronic components than i do, so i shall be listening out for any more suggestions! :D

 

"Though you seem to know rather more about electronic components than i do.."

Haha! No! I must just sound like i do :D
I've done bugger all with all this electronics malarky - I've just picked up a few things from some of my colleagues at the uni i work at. My stomping ground is very much in the mechanical area. I've discovered that asking anyone in the know about an electronics query is likely to result in lots of words i don't understand. So I was the same as you - "Mr electronics guru -this thing doesn't work, please provide me with a bigger one, so I don't have to tax my brain about it --- what do you mean, I have to work it out for myself?!"

Apparently there is more than one way to skin this cat. I'm hoping that as long as a transistor can take the power, then it will be a good replacement for the buggered one (its a TI EP2573, by the way).
You say yours is on the tunnel in the 79? with mine it's in the jack box. Does your car have a slider switch (like mine) to operate the wipers? Or is it like a UK car with the arm on the column? Just wondering how similar they are.

I'm expecting to get a replacment trans from RS - they make everything in the world! http://rswww.com You might have to register with them, and I think they only supply to the trade - but I bet you're bound to know someone who has used them, like i say, they supply everything.
If not, I suppose maplin would do, i'll have a look at their site. I reckon anything that will take about 100 Watts. Measure your motor's current draw and voltage into the controller. If like mine, all the power goes thru the big trans, then current x volts = power (Watts) rating you need.
I'm gonna try and get this killed off before the end of this week, so hopefully I'll have a good answer then.....
:cheers:

 

Theo,

Sorry, I don't remember where I saw the schematic but I will try and see if I can find it. If/when I do find it, I will send it your way.

 

That would be cool if you do. Cheers
By the way, I've had a thought about your wipers. On the front cover of the motor is a red or pink wire on its own. This is supposed to ground out on a little cam inside the motor, every time the wipers make one revolution. So in delay it tells the controller to cut the power and start waiting. If you disconnect this wire, then intermittent becomes "slow" since the controller doesn't know when to stop! Found that out by accident whilst fiddling around with it....
I wonder if this is your problem? Unplug that wire (the plug is close to the motor) and also the controller. You should get close to zero ohms if you do a continuity check between the red wire and the pink/black wire at the controller multiplug. (They must splice/change color somewhere in the belly of the car!) Hopefully that will check out. Then pull off the black plastic motor cover and you'll see that the red wire is attached to a 27 ohm resistor in series with the contact that grounds on the cam. Check that too -
Who knows it might be a quick fix after all. Wish it was just that with mine.
Good luck mate
:cheers:

 

Yep Theo, mine is a slide switch on the dash, just like yours... i think the only difference is where the control module is (probably a lot cooler in the jack box!)

 

Very true...
I wonder if the control modules are basically the same. Perhaps i'll post a pic of mine at some point (when i can find the digi-cam!) so you can see if your is at least something like the 80 one...
I'm sure they must be pretty close.

:cheers:

 

OK, Skeets ( and anyone who gives a poopie :D )
If you're looking to make a better choice of replacement for the main transistor, I have a bit more info. I was wrong about the power requirement needing to be 100Watts or so - I had a chat to an electrician today, who explained that as long as the replacement can handle the current (around 6 to 8 amps tops in mine), and has a voltage rating that is about double the alternator's 14V (this is to allow for spikes in the supply voltage to the board - never even thought about that) then it should be ok.
I had just got carried away having measured the current - knowing that electrical power is amps x volts, i thought that this was what i had to do to get the right rating for replacement. Apparently even though a Wattage is listed in the specs of the transistor, in this case it is not the important thing. Don't ask me why!
So if you find a replacement of say 10A, 30V, then you should be getting somewhere. It's a power transistor, and I think an NPN type. I've got a few more things to do with my board before i get round to replacing that trans, so I'll not be able to test what I've just written until then. When i get a replacement I'll post the number - if it works! - til then at least you know what to look for....
:cheers:

 

Hey Theo,

I have not been able to find that schematic that I thought I had seen. Maybe I imagined it. I will keep looking though. Thanks for posting all the useful info. that you have been giving us. The wife is going to NYC tomorrow, so I will be on solo dad duty and unable to get to my car until next week. ...and the weather is just perfect here right now for doing such activities. Once I get into this thing, I may hit you up for questions.

 

No worries mate,
I'm still trying to finish my own drawing of the circuit board - I've had to get a little help from people more in the know than me, but as i get further with it, I'm beginning to partly understand how it works.
If you've got any Q's about the wiring side of things, I've sorted that in my head now, so ask away! :D
:cheers:

 

Splendid work Theo! ... :cheers: