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Andy,
I can go on an on about troubleshooting needed, but if you're electrically disabled, then you'll save lots of time and patience if you pass it to a good specialist (and that's not me since you're there in the Elvesland and I'm here in Mordor which is quite away from you across the ocean). I'll go on with my moonspeak and you decide whether it's worth it or not.
The 1st step is to troubleshoot each fault and then try to find out what's in common among them. If nothing common can be found using common sense, then having your hands on your voltmeter you dig into the wiring checking all the circuits suspected.
I'll be referring to Bentley (16V edition) wiring diagrams because this manual is a must to have for every C900 owner and much more easier to get than Saab Factory manuals.
1. Fuse #7 blows away right when you click the stalk switch.
Diagram 'Direction Indicators an Hazard Warning Lights 1985-1990' on the page 371-56 (why this diagram and not any other? because it's the only one featuring the stalk switch) shows, that fuse#7 protects your blinkers when they run on the stalk switch and that it's the fuse#27 to protect them when they run on the hazards button.
A fuse goes blowing when there is an excessive current flowing thru it. Like a short circuit or too heavy load.
What's in common between direction indicators and hazard lights? Well, the bulbs and the relay (and the wiring from wires 76 and 79 and further down the road to the ground point #9. So either you have a short-circuit there or flasher relay is bad or one or more of the bulbs (or socket) is bad.
2. There are only ~7 volts between pin#49 of the flasher relay socket and a good ground (btw, you did check it against different grounds like the next pin#31, ignition lock housing, cigarette lighter housing, the car body, didn't you?)
A voltage drop happens when there's not enough current capacity in the circuit: like instead of a good thick wire current has to flow thru a single half-broken thin conductor. Or instead of a good solid connection to either pole (like the positive pole or negative which is also called the ground) there is some additional load (read: resistance) en route which is usually some sort of wiring/connector corrosion. Or there's a short-circuit somewhere above the load which overloads our voltage source.
Flasher relay socket pin#49 gets its voltage from hazards button pin#2 which sources it either from fuse#7 or fuse#27. So you have to measure the voltage on that hazards button and fuses to see whether on the circuit happens the voltage drop.
How you do that? You pull out the hazards button with connector still connected and put your thing (voltmeter probe) onto the required pin thru the read end (in other words: not breaking the circuit, not removing the button from the connector) while having the other voltmeter probe on some ground point. And, yes, it's worth to check voltages against different ground points.
The same goes for the fuses, but you need to unscrew those screws which hold the fuse panel and rise it a bit to get to the fuse contacts.
A good battery voltage on the fuse will tell you that problem lies down the circuit closer to the flasher relay socket. And that the problem is - most probably - a half-broken wire. But if you measure less then battery voltage, then either the problem happens above the fuse or it's a short-circuit down the fuse.
3. Parking brake and brake fluid indicators go lit when they should not.
Flick thru the Bentley until you're on the page 371-47 'Combined Instruments 1989-1990'.
Respective bulbs 47M and 47F go grounded thru their switches like part 43 and 192 (parking brake lever switch and brake fluid level switch), but they also have a constant connection to the ground thru the wire 182A and alternator indicator 47E and wire 195 - and finally thru alternator brushes and rotor. So to make mentioned bulbs lit one has to have some voltage on the wire 123G/I which originates at fuse#22. This can happen e.g. thru some shortened wiring loom or... if ground point#3 is bad and instead of flowing into the ground in this point the current from the directional indicators in the instrument cluster (those green arrows) comes to the negative rails and jumps on to the positive rail (the wire there that very 123G/I wire comes to) thru fuel and temperature gauges.
See the procedure above on how to check the potentials to determine what makes those bulbs light up.
Zig
posted by 5.18.17...
, Sun, 13 Jul 2014 18:48:45
, Sat, 12 Jul 2014 18:12:00, Sun, 13 Jul 2014 07:47:41, Sat, 12 Jul 2014 16:43:37, Thu, 17 Jul 2014 09:57:39
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