This has me really baffled.

Couple of days ago I'm pulling into work and about halfway across the parking lot the 122 dies. I coast into a parking spot.

Car won't start, but it will fire a bit when cranking. Upon further investigation I find I have blown the #2 fuse (from the top). OK, replace this and it runs.

Try to drive and it dies after about 10-30 seconds. Replaced fuse three times, same result. It idles fine but won't drive.

Any suggestions where to start?

From factory I have changed to alternator and Bosch electronic ignition (ignition pulls from same fuse that blows but has an inline fuse as well which doesn't)

The alternator was done 1.5 years ago and the ignition three months ago. Not had problems since initial installation bugs.

Anyhow your opinion is appreciated, this is a strange one.

Thanks,

-Mario E.
Lawrence, KS

To the brake circuit. I'll be tracing it down over the weekend.

Thanks to all for the pointers.

I plan on replacing my fusebox with one of Ron's gas-tight replacements while I'm focusing on wiring. After roaming over town searching for the Euro-fuses it would be nice to be able to use the little glass guys. Don't have the luxury of being in Volvo-friendly Northwest and longer.

Thanks again,

-Mario

Mario;

I'm glad to see that you're making progress finding the cause of the blown fuse. It shouldn't be too difficult, observe color code (Red is brake Light circuit), and instead of blowing any more fuses, connect a continuity checker/beeper to the Fuse2 output terminal (the one with the Brown wires, fuse blown or replacement removed, IGN OFF), it will beep and continue to beep until you remove (presumably) the short to ground...beware though, it may beep just from the two lamp filaments, so check the actual resistance in Ohms too!

Another hint: Locate connector for rear end lighting (under dashboard, at Dr side A pillar, Item 24/Junction Unit at: http://www.intelab.com/swem/122S%20Wiring%20Diagram.jpg) ...disconnect to seperate entire rear end wiring...Divide and Conquer electrical problems!

Good Hunting!

Mario;

It sure sounds like the electronic ignition may be the cause, although if there is a diode to the Terminal 50 of ignition switch, similar to the other electronic conversions, and this diode is bad, this could explain the symptom of firing during cranking, but not running after that....

...but, you need to figure out what blows F2 for starters!

Also. What rating is F2? Fuse2 is originally an 8A fuse...and all of the loads it supplies (Reversing lights, Horns, Brake lights *) are only "occasional use items". If you added the Ignition load to this fuse, did you increase it's rating (by the amount the ignition system's inline fuse is rated at)?

Which side of the Fuse2 did you power the IGN system from...by wiring the IGN sys to the protected side, you might think your doing a good thing, but a blown F2, due to for instance a shorted horn, will dissable the IGN...not so good....it should be the INPUT from IGN switch, so that blowing f2 doesn't kill the IGN...(it has its own fuse anyway).

Good Hunting

* reference: http://www.intelab.com/swem/122S%20Wiring%20Diagram.jpg

I took a look at the wiring diagram in the Haynes manual. If #2 fuse is the same as #2 in the diagram, then the following things are routed through that fuse:
- brake lights (through brake contact);
- horns;

Thogether with the small 25 A fuse this 8 A fuse is switched by the main (ignition) switch. Therefore it only gets juice (and burns through) when the ignition is switched on. By disconnecting the brake lights and horns you can try and run the engine. If the fuse blows, then it's the ignition (what's the ignition's own fuse rated at?), otherwise connect the horns and try again. Repeat process for brake light if fault did not occur.

When fuse blows trace the fault in the circuit that was last reconnected. I would not be surprised to see damaged insulation or something like that.

I would imagine that something on that circuit has developed a short circuit. Probably not the electronic ignition, but that is a possibility. You could try taking off the wires on that fusebox one by one and narrow down to what is pulling so much current the fuse blows. Then trace that circuit along to find the problem. As a temporary 'get home' fix you could just move the elec. ignition to another fuse box ciruit.

Moving that elec ignition to a different fuse would also help narrow the problem to either the ignition itself, or something else... Be sure to wire it to an appropriate place though such that it only gets power with the ignition on. I would think that ideally, you would wire it to an un-fused side of the fuse box being that it already is protected with the inline fuse.

-matt