Archived Check Eng. GEN. flashing. Not charging.

[JScanny]

2nd Generation 1997. It just recieved a kdp jig fix and a new idler pully and acted up so bad on the way home 100 mile trip. Had to turn around any thing over 40 mph trans was banging and eng was cutting out. It was raining and getting dark. Auto wurks swapped a electronic power control to get me home it did the same thing!They now tkink its the alternator generator. it was puting out 8 volts then jumping up to 12+inbetween flashing? I had to rent a rice burner to get home!#@$%! Any boddt have this happen to them?

 

[BigPapa]

My '95 did this last summer. Took the truck to Auto Zone, it's just across the street, they said it was OK. Took it to Advance, they said it was OK. Took the alternator to a shop that rebuilds alternators. They cleaned it, put new brushes in it, and I haven't had a problem since.



Scott

 

[GAmes]

It sounds to me like after the KDP fix that the engine speed sensor was not reinstalled correctly. It needs a . 050 inch gap from the damper.

 

[BigPapa]

I agree with GAmes. I missed that part... ...



Scott

 

[WDimig]

if you gen light is on, then it is your alternator, but do double check the air gap between the harmonic balancer, and the tach sensor, stick a piece of cardborad (like from a cereal box, dont use corrugaged, wayy to thick) between the balancer, and sensor, push down, the magnet will hold the sensor to the balancer, tighten the nuts, and remove the cardborad. when my alt. went out recently, the gen light came on, and i had no charging at all, replaced alt. , light went out, and batteries charging normally. good luck with your problem.



wes

 

[Dave M]

If the GEN light is ON it doesn't necessarily mean the Alt is bad! I know this from experience. On my 97 the CPS went out and symptoms were GEN light on , no alt charging, no TACH, no MIL light with initial key on sequence, speedometer not working. Some dash gages functions worked. So a GEN light may not mean a bad ALT... it could be CPS, especially when those other functions are dead. The PCM needs the CPS to control those functions.



See my CPS thread for more detail:



https://www.turbodieselregister.com...ons/184945-electrical-woes-maybe-bad-pcm.html

 

[Skydiver]

When my cheap factory grid heater relays would stick closed my alt. light would come after 4 miles of driving. Remedy: disconnect one wire from each relay.

You can tell by the volt meter staying below 11.

 

[Dave M]

When my cheap factory grid heater relays would stick closed my alt. light would come after 4 miles of driving. Remedy: disconnect one wire from each relay.

You can tell by the volt meter staying below 11.

Humm. . interesting. Maybe the huge current load on the batteries caused the battery voltage to drop and ... for some reason... it shutdown alt charging so you got the GEN light.

 

[GAmes]

Humm. . interesting. Maybe the huge current load on the batteries caused the battery voltage to drop and ... for some reason... it shutdown alt charging so you got the GEN light.

When there is a huge load on the alternator the pcm shuts the alternator down, I assume to prevent overload damage. To reset it you need to only shut the engine off and restart it. If the grid heaters are not on there is no harm, no foul. I know this because I have the grounds to my relays hooked to a toggle switch in the cab. A few times I have forgot to turn it off after the engine has started, and once I turned it on inadvertantly while driving. I haven't burned up a pcm or alternator yet.



If Skydiver was able to disable the relays by unhooking a wire, then they were not "stuck closed". That would indicate to me a bad signal from the temp sender which would give a grounding command from the pcm.

 

[Skydiver]

Oh yes, they were stuck closed. Don't know if it was one or both. When I tapped they broke loose. Mine will crank at 20 F with no help. It ain't pretty!