Ever Feel THIS Dumb? I Do!

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Ever Feel THIS Dumb? I Do!

Postby SurferJoe » Fri Oct 14, 2016 9:31 pm

Last winter - actually the Fall before it happened, the high speed blower ceased functioning. It still had Low, Middle and Almost High - but no real High.

I've been down this road before and it was always the module after testing every wire there is under the dash - under the air bag actually - and inside the vehicle which might sound all nice and cozy except it's on a 2000 Chevy Astro. Remember if you will that an Astro has NO foot room on the passenger's side.

I pulled it out, found out the warranty had been exceeded and figured 'Hey - I can bypass this High blower circuit and add some wire, a relay and a fuse holder'.

I found the command line from the blower switch on the dashboard and cut it off and added the relay and some associated wiring including an inline fuse holder.

"It's fixed" I said as I called my wife to try it for herself.

"No it's not - it's just as broken as it was before" as she was looking at me with that face that I bet gets stuck that way some day.

"Oh [email protected]! - I'll get back to it in a bit" I said and the truth be told - I totally forgot about it until every time I drove the van and I complained about the blower not running fast enough.

A year went by.

Just yesterday I decided that once and for all, I was gonna 'look into it' now before the first snows hit and I needed the fast defrost to work.

  • I pulled the module and checked if it was any worse for wear since last time I saw it. it wasn't.
    I checked to see that my fantastic bypass circuit was still the way I left it. It was.
    I put the module back in and started probing the power to it in High mode.

Aha! There was no power going to the relay I had wired in. Doh! :idea:

Get ready for it.....................

It's coming....................

I'll tell you .........

Here it is: The fuse holder that I bought had a 10 Amp fuse in it. The blower needs at least 20 Amps.

I put a 25 Amp fuse in it just for extra scrim. It's running - and all this after a year of not having High Blower mode at all.

Anyone else want to volunteer for Big Dummy Awards?
Joe Vreeland - In The Bitterroot Valley, Montana
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Re: Ever Feel THIS Dumb? I Do!

Postby Von » Sat Oct 15, 2016 11:30 am

every. day. the hard part is covering my tracks so my wife doesn't get that look.

that is all i'm sayin about that.
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Re: Ever Feel THIS Dumb? I Do!

Postby RickP » Sun Oct 16, 2016 11:39 am

Bigger is better doesn't work with fuses and electrical. You want the fuse to before wiring melts.
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Re: Ever Feel THIS Dumb? I Do!

Postby SurferJoe » Sun Oct 16, 2016 1:04 pm

Both the Battery + and the feed to the blower motor are 8 gauge.

I think this is the reason for failure of two control cards.... One was digital but obviously not Pulse Width Modulated and the second was just a bank of resistors.

I took the cue of the second with the resistors to indicate that I didn't have to do any more than feed straight battery current to the High side for max blower operation.

It works and no smoke was harmed nor allowed to escape during the process.

Time will tell, but a Bosch 5-pin relay is holding it all very well so far. The NC pin keeps the rest of the card's other speeds/ranges operating until High is selected and then the relay takes over on the NO connex. .
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Re: Ever Feel THIS Dumb? I Do!

Postby DSUZU » Sun Oct 16, 2016 5:16 pm

I experienced something similiar with my Spacecab. I "lost" one (or two) of the lower speed settings. A quick check showed that at least one resistor was open. Off to the boneyard and I found what I THOUGHT was a solid state resistor pack (electrical plug and spades are the same orientation). Scarfed it, put it in, and now I have all my lower speeds, but NO high speed. Note: usually a blown resistor will always still have the high speed feature. Eventually, I tried another solid state pack with the same results. Finally, an old pickup came into the yard and I got the resistor pack from it. All works now. Try as I might, I never could get any kind of accurate resistance or voltage readings to determine exactly which leads on ths S/S pack work which speed. Maybe because of transistors? I thought about bypassing to get a high speed fan, but the old school resistor is doing it for now. Dennis
1991 LS Trooper 2.8 V6 5 speed conversion (Sold)
1989 LS Spacecab 2.6 5 speed 4x4 manual hubs, Rodeo torsion bars, extended shackles, 2" lift, K&N airfilter (drop in), dump bed conversion, burgundy interior change, warn brush bar.
Previously owned: 1987 Trooper II LS, 1989 Trooper (parts only), 1994 Trooper 3.2 Auto, 1997 Rodeo 2.6 5 speed, 1993 shortbed pickup 2.3 (project - sold) 1992 Rodeo 4x4 LS (parts car, devoured by Spacecab needs) plus some 70 plus other non Isuzu vehicles over the years.


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Re: Ever Feel THIS Dumb? I Do!

Postby itsmehb » Sat Oct 22, 2016 9:13 am

Anyone else want to volunteer for Big Dummy Awards?

Way back when I was 16 and the proud owner of my first car, a 39 Mercury convertible, Mercury's first production year, I decided I could save scarce money by changing my own oil. So off to the local pep boys (yes they were around then) and got some oil and a new cartridge filter. Got the filter changed and the old oil drained. Feeling totally in control, I added all the new oil only to see new oil running out under the car and approaching my shoes. YES, you guessed it, I forgot to put the drain plug back in. I had to wait a week till I had enough money to get some more oil. Sometimes the best lessons learned are the hard one's. I NEVER repeated that mistake again, and I still remember how dumb I felt.
1990 Amigo, 2.3 5 speed (sold)
1991 Pick up (long gone)
2000 Amigo, 2.2 5 speed(sold)
1985 Trooper 1.9 4 speed (sent back to KS)
1989 Trooper RS 2.6 5 spd. Red

We get too soon old and too late smart!
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Re: Ever Feel THIS Dumb? I Do!

Postby N law » Tue Oct 25, 2016 4:48 pm

I plead the fifth. :D
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