240 Issues of the day

So yesterday I changed the oil in Volvomort and was working a bit on the placement of the IAC valve. I buttoned it up and all seemed good. Just as I was pulling into the parking lot at work this morning, my battery light came on and all the gauges stopped working. Nothing else seemed to change, still ran great, my headlights, wipers, and heater were still on.

I parked the car, left it running while I looked under the hood, but didn't see or feel anything loose. After I shut the car off, it would not restart. Cranks over nice and strong, but does not start. Has anyone seen this before? Why would all the gauges turn off and it run, but not restart?

I am still at work and will mess with it on my lunch break....

So I popped out to the parking lot between meetings and it started right up. No lights on the dash or anything. Not confidence inspiring, but I will take it for now...hopefully it still starts right up when I leave for the day.

Check it with a voltmeter and see if the alternator is charging. Plus check the battery voltage before starting so you know how good the battery is. The gauges on many cars use a voltage regulator to supply a more stable operating voltage to the gauges. Those can randomly fail which would make your gauges not function. Or, if the input voltage to the regulator falls below a certain level it will shut down. While the engine can still run and things like the heater fan, and wipers would still work.

yugo4life said:

So I popped out to the parking lot between meetings and it started right up. No lights on the dash or anything. Not confidence inspiring, but I will take it for now...hopefully it still starts right up when I leave for the day.

Click to expand...

Symptoms tend to match what happens when fuse 13 gets crusty. In the 84, fuse 13 protects the wiring to the fuel injection and the instrument panel gauges and warning lights. What do you mean by "no lights on the dash or anything?" Are you saying some warning lamps do not light in KP-II for lamp test, or that none of them remain on when the motor is running?

dl242gt said:

Check it with a voltmeter and see if the alternator is charging. Plus check the battery voltage before starting so you know how good the battery is. The gauges on many cars use a voltage regulator to supply a more stable operating voltage to the gauges. Those can randomly fail which would make your gauges not function. Or, if the input voltage to the regulator falls below a certain level it will shut down. While the engine can still run and things like the heater fan, and wipers would still work.

Click to expand...

The battery is less than a month old, but I will check it and the alternator before I leave since I do actually have my multimeter with me.

cleanflametrap said:

Symptoms tend to match what happens when fuse 13 gets crusty. In the 84, fuse 13 protects the wiring to the fuel injection and the instrument panel gauges and warning lights. What do you mean by "no lights on the dash or anything?" Are you saying some warning lamps do not light in KP-II for lamp test, or that none of them remain on when the motor is running?

Click to expand...

Good question, I should have been more clear. When it originally happened, the battery light was on while the gauges did not work, but when I started it later, the battery light turned off and the gauges started working. This is different than other alternator issues I have had in the past when all the warning lights were on. I will check fuses as well.

If the brushes are very worn you can get intermittent charge issues like you experienced.