The Instrument Cluster Broke AGAIN on My Saab 900

[@thackerybrown2860]

A couple of friendly pro-tips for future soldering: get some solder wick - it helps you clean things up a lot (either removing original solder before starting your repair or cleaning up your repair work). also let the solder do the work for you - pre-solder the wire by holding it against the iron on one side and applying the solder to the copper on the other. As it warms it will suddenly absorb 90% of the solder you need for the job onto the wire itself. Then you press the wire to the surface you want to solder to and press the iron down on top of the wire and the solder will become fluid again and connect to both surfaces. Get very clean connections really quickly, without excess solder or holding the iron too long to the circuit you are attaching the wire to. can apply more solder to the junction if needed, but might not be if you got even a little of a bubble of solder on the wire in the pre-soldering stage

[@AutoAutopsy]

Thank you for the advice! 🙌🏼

[@MassiveTrackHunter]

Ahhh...the early years of circuitboard style gauge clusters....such a hodgepodge of flat strip and soldered on oddities. Kinda miss that easy troubleshooting era, compared to the pcb micro stuff on them now.

[@AutoAutopsy]

I guess it is simpler than the new stuff 😅

[@MassiveTrackHunter]

@@AutoAutopsy it was certainly nice that you could put new wires across failed tracings, something that would be much hard or impossible to do on new cars. Even though that classic drives you nuts, you would regret selling it. I wish I had not sold my SPG. The only car more fun in my 40yrs of owning, has been the viggen, but only slightly. Get her tuned with Swedish Dynamics, a whaletail, rear louvers, a wrap, and you will have a wicked looking toy that is reasonably reliable. I am keeping an eye out for another 900T to do that to. Take care. Hope to see you all at SOC.

[@austinvitoux]

Very nice! Glad to see you're enjoying the SPG on a cold night. It's the best time for boost IMO, especially when it's about 40 to 50 degrees F.

[@AutoAutopsy]

Thanks! It’s just a turbo, not SPG sadly :(

[@foamy_brawl9903]

Love your content brother, keep it up! 🫶

[@AutoAutopsy]

Really appreciate that! 🙌🏼🙌🏼

[@vincefromnh5332]

You probably noticed this, but the gas gauge on the pre-1993 900's are logarithmic to mirror the signal being sent by the float sensor. The gas gauge gives the true reading of the volume of fuel left in the tank.

[@AutoAutopsy]

👍🏼🙌🏼

[@MassiveTrackHunter]

Just wait til you get a mild tune on her. The way the boost just suddenly hits is unnerving, but will leave you smiling every time. Makes me miss my SPG.

[@AutoAutopsy]

Haha sweet

[@1873Winchester]

I think I might have used clear epoxy or a poly varnish on that repaired circuit myself, to seal it in. But the tape will probably do. Never heard of that type of tape before.

[@vincefromnh5332]

I bought my 1991 900 Turbo new. When I picked it up, the senior tech told me there are sensors which determine the octane of the fuel and adjust the injectors & timing. He said for optimum turbo performance, I should use 91+ octane. Whether he was correct or not 30 years ago, I don't know. But I religiously followed his recommendation. My 900 ran true & peppy for 325k miles before I sold it, to my regret now, in 2005.

[@AutoAutopsy]

That’s sorta what I figured. Thanks for confirming!

[@barenekid9695]

Either use Magnet wire OR silicone jacketed wire... as Heat doesn't melt the insulation.

[@adamfriedstein7614]

Nice work. Looks like you are stuck in base boost (5-6 psi). Could be a vacuum leak, apc issue, or pressure transducer... once you get that sorted out the car will be much faster ;)

[@AutoAutopsy]

Thanks! Hopefully now I can get back to the mechanica issues, so that’ll have to be one of the items

[@TheBTG88]

Did you take to opportunity to replace the gauge cluster light bulbs with LEDs to get a better light field?

[@AutoAutopsy]

Nope I just used the standard OEM bulbs

[@ivarkwant6607]

Have you thought about changing the steering wheel? IMO the three-spoke looks the best, especially since you have the rims to match ;)

[@AutoAutopsy]

Would love to! If I can find one at a decent price 🤨

[@ivarkwant6607]

@@AutoAutopsy yeah I guess they're quite hard to find these days :/

[@tompettersson3814]

It boosts less than baseboost. So it is probably about 135hp. Boostgauge should almost reach the red if everything is as it should :)

[@AutoAutopsy]

Yeah I’m sure I’ve got an issues somewhere haha

[@tompettersson3814]

@@AutoAutopsy check the magnetic valve and the function of the knocksensor and also adjust the baseboost (wg actuator) to 0,45. (Middle of the orange)

[@ThePrissy11]

I tried all three gas grades on my 9-3. It definitely runs best on 89.

[@AutoAutopsy]

If it’s stock you can probably get by with that!

[@1873Winchester]

I would pay ~120 euros to fill up my 900

[@raffe65]

🫡👍🇸🇪

[@AutoAutopsy]

🙌🏼