1990 with Weird, Weird Electrical Problem

[TheOneEyedBandit]

Hi, folks. Here's a strange one for ya: what could fail and cause loss of spark, and also loss of power to the fuel pump relay, at the same time? The reason I know there's no power to the relay, is that I bypassed it with a toggle-switch a long time ago (the darn thing went bad on the side of the road, and a new one costs about $50).

It was sitting in the yard running (I was adding some stop-leak to the AC, if that means anything), and just shut down, like I'd turned the key switch off. Is there some hidden fuse, or fusible link, or maybe even relay, that could have gone bad?

The engine will crank and crank and crank, but won't catch or even sputter, everything else seems okay, but no spark, and no power to the fuel-pump relay.

By the way, I know this is probably a dumb question, but my service manual is a joke, and I can't find a half-decent wiring diagram online. Oh, well.

Thanks.

---Joe

[billburns]

I have had a 90 and 92 240 with the same symptoms as yours. Each time it happened I found that corroded connectors in the fuse panel was the cause of my no start problem.. The way to check if there is a problem with the connections is to perform a voltage drop test from one fuse tab to the other.. To fix the problem clean the tabs that hold each fuse in with a brass brush or emery cloth and clean or replace the fuses. To prevent this from happening again coat the tabs and fuse ends with silicone dielectric grease. Good luck Bill Burns