'84 died on the road, restart - died, then no restart

optimusprime · 05-26-2007, 07:25 PM

My '84 died right as I was rolling through an intersection, coasted to the side of the road - restarted. I'd say it ran for about two seconds then died. Then, no restart - all lights, gauges, radio, dead - no cranking.

Enter helper - hooks up jump leads, so I can at least roll up the windows - turn the key, start right up. I get out, unhook jump leads, by the time I get back to the driver's door, it dies. Repeat that twenty minutes later (maybe about 20-30 sec running, then dies). Once more, jump it - this time I rip off the jump leads, hop in, and speed away at about 60mph in town and make it home.

I'm pretty sure it's not an electrical problem, since it did die in mid-run. Any ideas what is to blame?

nynor · 05-26-2007, 07:32 PM

sounds electrical to me. alternator?

mjadair · 05-26-2007, 07:33 PM

Sounds like an alternator problem. Once voltage levels drop enough, the car cannot run at all. Jump will get the car going again but only until charge is depleted in battery. If you charge up the battery, start engine and pull the ground cable off the battery. If the engine dies the alternator is to blame.

optimusprime · 05-26-2007, 08:40 PM

OK, I'm showing 12.06 VDC at the batt. Running, though, I only get 13.6 (perhaps alternator, perhaps otherwise, I'll have to check the drop over the alternator later/tomorrow). I'm also pulling about 90mA at rest (too much, right?). So, I checked my fuses - turned the key, hit the headlights - dead, lights off power gone. I had to wait a few minutes before I could try again and it worked. Then I noticed something else a bit disturbing. Both side markers on the passenger side are out (despite an intact fuse), as well as the right side reversing (white) light. Also, the passenger side window switch doesn't work (the switch is good), though that window can be controlled from the driver door. Might I have a short somewhere in there that is draining the battery? (In addition to another potential alternator problem?)

Eldorado · 05-26-2007, 09:10 PM

cheap stuff first - take your battery for a free test at an autoparts store. after that, if you have to, dig out and take the alternator.

as for the lights, try changing the bulbs... if they blow again, you've got a problem..

have you done anything to the lighting/electircal system lately? anything at all? even something as little as change some bulbs..

onZedge · 05-26-2007, 09:33 PM

Never disconnect the battery, with the engine running, on an ECU equipped car!! Alternator may output unregulated voltage, and that will fry the DME.

optimusprime · 05-26-2007, 09:36 PM

Quote:

Originally posted by Eldorado
have you done anything to the lighting/electircal system lately? anything at all? even something as little as change some bulbs..

I was checking out a problem with my current draw - removed and replaced a few relays to see if I couldn't find the root of that problem. (I didn't.)

I really don't think it's a coincidence that the entire right side of the car is electrically crippled and the rest works perfectly. Ashtray light works fine - glove box light doesn't. Clock doesn't work, the two warning lights for seatbelts and handbrake don't work, as I've mentioned - no side markers, no right side reversing light.

(Also, I don't know how to get at those bulbs to check them.

optimusprime · 05-28-2007, 01:55 PM

Update: The side marker lights are operable, I switched them to the other side without a problem.

I started pulling some fuses, from a baseline draw of .160mA. At fuse 7, that drops to .060mA. With fuse 7 in and the driver's door open, I draw about .8mA. With the passenger door open, I still draw the same baseline .160mA. This leads me to believe my short is somewhere before the passenger door switch... can anyone confirm?

joliett · 05-28-2007, 11:09 PM

It's your car's computer brain. Under the passanger's footwell rap the computer case and then try and start. If it does - resolder the larger connections in the computer...wanna bet this is it?

SoCal Driver · SoCal Driver's Garage

Quote:

Originally posted by joliett
It's your car's computer brain. Under the passanger's footwell rap the computer case and then try and start. If it does - resolder the larger connections in the computer...wanna bet this is it?

I'll take the bet! The early 944's have the DME under the steering column right about the drivers knees!!!

Can still have loose solder connections.

I would check out the battery for a dead cell and clean the heck out of all it's electrical connections and the grounds between it, the chassis and the engine.