charging problem self inflicted .

jimjimjimmy

lobsterman
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i was working on a slight over charging problem on a 1990 w250 cummins and i accidently grounded the two field wires together when i was running a jumper wire from the hot field to the battery , the allagator clip grounded the fields together now it's not charging . did the alternator burn out or would it be the regulator . Thanks
 

67Dart273

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If you had any of the field connections in place you could have hurt the regulator. I'm pretty sure those use an isolated field just like the older Mopars on here. Just check continuity---with no vehicle wiring connected to the field terminals, you should have continuity between the two, and open to ground. You should be able to ground either terminal, and jumper 12V into it and see a small spark in sudued light. I don't know what the current draw is on those, but surely it's 2-4A maybe up to 6A or so.

I'm not very familiar with those, you have a link to a diagram? Does it use a firewall mount VR?
 

jimjimjimmy

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If you had any of the field connections in place you could have hurt the regulator. I'm pretty sure those use an isolated field just like the older Mopars on here. Just check continuity---with no vehicle wiring connected to the field terminals, you should have continuity between the two, and open to ground. You should be able to ground either terminal, and jumper 12V into it and see a small spark in sudued light. I don't know what the current draw is on those, but surely it's 2-4A maybe up to 6A or so.

I'm not very familiar with those, you have a link to a diagram? Does it use a firewall mount VR?
yes it has the external electronic regulator . it has two fields one goes to the top post of the reg and the other field goes to the ing terminal along with keyed power .
 

jimjimjimmy

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well i guess i will just buy and through another regulator on and find out i guess .
 

jimjimjimmy

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well if anyone is interested the truck was charging at 17.3 volts , way to high so i cleaned up all the connections and the grounds real good and added an extra to the body and i got it down to 14.8 the best i could get , still to high so i tryed a transpo adjustable voltage regulator and it was at 14.6 so i adjusted it to 14.3 and now it's charging steady and solid . two thumbs up for the Transpo adjustable regulator .
 

67Dart273

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The thing is, and I've preached this, LOL, is that "too high" voltage is almost always a matter of the VR not being at battery voltage. This means voltage drop in the harness and ground systems.

However, some? many? most? solid state VR's are temperature compensated, and in fact if they weren't would likely vary with temperature anyhow. So make sure you check it with system warm and battery "normalized." On the older Mopars, there's a chart in the service manuals that equates temp to charge voltage.

I understand your frustration!!! This is a common problem
 

jimjimjimmy

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The thing is, and I've preached this, LOL, is that "too high" voltage is almost always a matter of the VR not being at battery voltage. This means voltage drop in the harness and ground systems.

However, some? many? most? solid state VR's are temperature compensated, and in fact if they weren't would likely vary with temperature anyhow. So make sure you check it with system warm and battery "normalized." On the older Mopars, there's a chart in the service manuals that equates temp to charge voltage.

I understand your frustration!!! This is a common problem
Thanks for your help i will run another test today .
 
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