Voltage spike...?

[rich weyand]

No problem.  We always think of engine, frame, and cab as being ground, but in fact they are all shock mounted to each other, so there have to be ground straps -- cab to engine to frame -- to get them all to agree on "ground".  Easiest thing in the world to leave one off when you work on or replace the engine, and then absolutely anything can happen.

[454Man]

This morning I tested out the new ground I added last night. I cranked the AC, radio, and fiddled with the windows. Nothing bad yet :-) we will see.

[454Man]

Well still have the problem guys. Did the same test and back to the old prob. Except this time after I turned the blower motor down off high.

[454Man]

All went back to normal... I'm gonna try taking the fuse box apart from the fire wall and see what I can find

[454Man]

Well cleaned the contacts on the fuse box connectors and still... I'm ok if I don't turn the fan on high, head lights and all... Just the fan. I really don't think it's the fan because I've had it unplugged b4 and had the same prob... Dang

[454Man]

BD where is this resistor wire your talking about? I'm still at a lost. I think the next thing will b is to upgrade the charging wire from the alternator

[bd]

Keep a cool head.  You'll find the problem if you're systematic.

Absolutely verify that the alternator is properly grounded by installing a temporary jumper between the alternator case and the battery negative post.  This should determine beyond any doubt whether you still have a ground problem to correct.

If the temporary ground jumper doesn't correct the problem, take a very close look at the red, 12-gauge wires that feed power into the cab from the starter.  Inspect the cable connections at the starter, firewall junction block and bulkhead connector for any signs of looseness and/or heat stress.  Don't tear the fuse block any further apart just yet.  Simply unplug the connector on the engine compartment side and look for heat damage, distortion of the connector, etc.  You may need to clean away the black sealant to see the connector and terminals clearly.  Concentrate on the heavy-gauge red and pink wires. 

Based on what you've posted to date, I think you're going to discover an intermittent connection problem in a 12-volt feed circuit that breaks down when stressed by high current flow.  When the poor connection manifests under electrical load, it drops the voltage applied to regulator wire #2, and the regulator boosts output voltage to compensate.  Pay particular attention to where the #2 regulator wire ties into the main harness.

Trace both regulator wires as posted previously.  Report back with what you find.

[454Man]

Meant to say BD.... typing on phones ain't a good thing.lol I'm good.

[454Man]

Bd I'm thinking the same as what you said. Tomorrow after work I'll chase some wires and clean connections. This has got me stumped...

[454Man]

Forgot to say this is also my second starter. I've kept a tab on things changed. :-)

[bd]

These wiring references will be your best friends if you refer to them regularly: the 1983 Wiring Manual (page 9) and the more generalized 81-87 Wiring Diagrams.  The 1982 Wiring Manual is missing from our library.

Circuit 25 (brown) is the #1 regulator resistance wire to which I referred (look at the diagrams for an illustration of where the wire should be routed).  Circuit 25 is the 'exciter' lead that turns the regulator ON initially with ignition power.  It's not likely your issue is with this circuit, but you need to verify where it connects, nonetheless. 

Circuit 2G (red) is the #2 regulator wire that should connect directly to the starter through a fusible wire.  The #2 wire is the 'sensor' or feedback lead the regulator uses to adjust alternator output.  If not a ground, the culprit is most likely in this wire or between the starter and battery, hence, zieg's early post to verify battery cable condition/connections.

To resolve your issue as efficiently as possible, try to avoid making any assumptions.

Once you correct the actual fault, I'll provide an upgrade to a more effective design that will help alleviate this type of problem in the future.

[Irish_Alley]

on your battery whats that alligator clip for?

[454Man]

Fan motor I thought going straight to the battery would help.it did help a little

[454Man]

How new are your battery cables?

Idk I guess I could ohm the positive wire

[bd]

Don't measure cable resistance; do a voltage drop test!  Voltage drop tests are dynamic tests.  Resistance checks are static tests.  Your ohmmeter isn't sensitive enough to correctly register the small resistance that could cause an operational problem in a high-current circuit.  Whereas, measurable voltage loss across a cable is a dead giveaway.  Resistance measurements have their uses, but are best suited to low-current circuits.