mopar2ya

This just started happening. When I start the truck the check engine light stays on and the volts are low for 30 seconds to 2 minutes then they come back up. If I shut the truck off and restart it the check engine light is off and volts are good. I wonder if the regualtor is crapping out. Is the regulator on a 93 in the computer or in the alternator?

kerryneb

Unfortunately, the voltage regulator in a '93 is in the computer. May not be a voltage regulator problem though. If the weather is fairly cold, and you're cranking and starting before the wait to start light goes out, the grid heaters can draw more current than the alternator can generate (or maybe the computer doesn't turn on the alternator until grid heaters have cycled, i'm not sure which.). Also could be a sticking relay. You can test this theory by disconnecting one of the 2 small wires going to the grid heater relays at each relay. Another possibility is alternator brushes are about gone. If necessary, you can use an old style external regulator instead.

wannadiesel

If it's turning on the CEL, you should have a trouble code to work with.

Turn the key on, off, on, off, on and leave it on. The CEL will blink out the code. Your code will probably be forty-something, so you will get 4 flashes, a pause, then some more flashes. The code will help figure out the problem.

boomer

Gee, this problem sounds so familure. Mine started out the same way and as time progressed it took longer and longer to activate the charging system. (Heat grids disconnected). If it was very cold, sometimes 5 to 10 minutes of engine running. I suspected the computer. I switched to an external voltage reg from a 92. Charging problem solved but no check engine light or wait to start light. If I do the key thing for the trouble code, I get nothing. Next, intermittent failure of the relay solenoid so I replaced solenoid and ignition switch. Problem still exists. Now, I have no speedo, power windows or heater. Everything else works. Wannadiesel, got any ideas???

mopar2ya

i always wait for the light to go out, it does it even when the block heater is plugged in and the engine heater grids arent needed, but the problem goes away within 30 seconds when the block heater is used as opposed to several mnutes when cold. I guess whn I do the head gasket, I can check the alt brushes, but normally when they are going you can smack the alt bracket and the volts will jump back up. No suck luck this time...

wannadiesel

In your case it sounds like you fried a fusible link. HVAC and power windows share one. I doubt this is connected to the lack of a charging system, that's a whole 'nother problem. Because the WTS light and speedo are out, I'm guessing you have a problem with the 5v signal to the sensors. Either it's fried or there's a bad connection.

Mopar2ya, got any codes for me yet?

mopar2ya

codes are 11-12-41..

kerryneb

11 is crank position sensor... that will cause 41-alternator charging circuit to fail. 12 is just battery recently disconnected. check voltage going to the crank position sensor.

mopar2ya

I will do that, thanks for the info.

wannadiesel

Also check the gap on the crank sensor, should be 0.050", use a brass feeler. And follow the wire to make sure there isn't a chafed spot or a flaky connection - there's a plug at the front of the head that could be a trouble spot.

On the code 41 - check the connections at the ASD relay, it's the one closest to the front on the fender. You can swap it with any of the others to check for an "iffy" relay.