a/c blower speed control

What version 1990 TR -- euro (F113B engine) or US (F113A040 engine) or ?

What is your symptom -- 1. no fan blower at all, or 2. fan blower only works at max speed setting, or ?

 

Most likely the power transistor has failed.

Do a search on "TR power transistor" and read those 19 threads for a good background.

Send me a PM with your email address, and I'll be glad to email you a scan of Fig 9 (AC) from the US TR wiring diagram book 509/88 for the 1988-1991 US TRs:
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I had the same problem with my 1990 TR. The problem was indeed the power transistor, which is buried inside the duct work under the dash, so that it is cooled by the flowing air. I was lucky, though. Turns out that the transistor is grounded by its attaching screws. All I had to do was clean the screws and mounting lugs, and put it back together. -Steve

 

Hi Steve could you get me copy of the diagrams as well. [email protected]

 

You can get a pdf of the entire 509/88 US TR wiring diagram at All Ferraris (click The Downloads, click Other Manuals - it's at the bottom of the list).

 

Is'nt there a fuse just beside that knob to adjust speed (just like Mondials have) ? A blown fuse also has that symtom...

Guido

 

Same problem here easy fix i got 2 new ones on e bay for $10.00 still have one left ,there is a number on the transistor just punch it e bay and it pop,s up,unsolder the old one and resolder the new one.

 

On the early TR speed control (with knob) ECU = yes, but it was eliminated on the later TR speed control (with knob) ECU.

 

I think this is what you need
Part # 2N5086
0032
MEXICO
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This is the back of it
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Although the printing looks like "2N5086", I think that it should be 2N5886 (2N5086 is a different kind of small amplifier transistor in a different package).

 

You could be right a bit washed out on mine