Voltage regulator?

steiner_5000 · Post by **steiner_5000** » Fri Feb 16, 2007 10:02 pm

I just got done doing a 4.0 swap into a 85 B2. Anyway I cant turn the motor over with the key. The dash lights and CD player turn on when the key is on but then turn off when I turn the key to the start position. So I try to start the truck by "arking the solenoid" and it worked fine until it starting smoking under the battery box. I'm thinking it came from the voltage regulator because theres nothing else down there. Now could my problem be that the voltage reg. is shot or could my clutch switch be shot?

steiner_5000 · Post by **steiner_5000** » Sat Feb 17, 2007 9:28 pm

Does anybody have an idea?

Bob Myers · Post by **Bob Myers** » Sun Feb 18, 2007 9:37 am

SOunds like the engine is either locked up or starter is dead. Smoke from under the battery tray would likely be a ground wire, voltage reg is internal to alternator

steiner_5000 · Post by **steiner_5000** » Sun Feb 18, 2007 11:50 am

But I can turn the motor over just fine, just not with the key. It turns over nice but wont start.

Bob Myers · Post by **Bob Myers** » Sun Feb 18, 2007 12:21 pm

OK, that is not what I read in your post earlier, now that we have established this; did you isolate the source of the smoke. Smoke is very bad.
Chek the clutch switch with a volt meter, is there voltage on both side of the switch with clutch dpressed and key in start position? If so move on the solenoid mounted on the fenderwell. Is it reciving voltage from the single small wire coming in to the pushon connecter in the front/center?

steiner_5000 · Post by **steiner_5000** » Mon Feb 19, 2007 11:29 am

Could this have anything to do with the ground strap on the back of the motor because I have that bolted onto the body. Its where it came off in the other truck.

BDEUCE · Post by **BDEUCE** » Mon Feb 19, 2007 11:54 am

no, probably has nothing to do with that. try the things the other guys told you.

Post by **Nobody** » Mon Feb 19, 2007 12:51 pm

Your starter circuit goes through the the plug that goes to your tranny. Since you did a motor swap, that would a good place to check. If I recall correctly, it's a red wire with a blue stripe. The starter solenoid itself could also be bad.

The votage regulator isn't under the battery box. The only thing I can think of under there is where the battery ground cable attaches to the frame, and then goes to the engine. If it arched there, then it's very likely that the ground cable isn't hooked up to the engine, or it's a bad connection.

DBrown · Post by **DBrown** » Tue Feb 20, 2007 5:28 am

did you alter the 4.0l harness or the 2.9l harness?

the starters for the 4.0L are a gear reduction starter so they need to be wired different then the 2.9L starter.

my advice is to start with the problems as seperate problems then one large one. it will make the trouble shooting easier.

steiner_5000 · Post by **steiner_5000** » Tue Feb 20, 2007 8:29 am

What I did was I found the ignition wire from the old harness and just ran that directly to the "I" post on the solenoid. Then wired the starter in the same way it was on the explorer. Little red wire to the "s" on the solenoid and the big cable right to the battery. Will this not work?

steiner_5000 · Post by **steiner_5000** » Wed Feb 21, 2007 9:19 am

Isnt this right?

DBrown · Post by **DBrown** » Wed Feb 21, 2007 11:25 am

the starter sounds right but I don't know about the other wire...

do you have a volt meter?

if I remeber right the voltage regulator is in the alternator

ranger5.0 · Post by **ranger5.0** » Thu Feb 22, 2007 7:51 pm

The trigger source to kick the solenoid on is on the same side as the 12 Volt battery in pole. The other, I believe puts out a 12 volt kicker boost to the coil to help start the engine. Most of the electronic ignitons don't use this option anymore since they rely on full twelve volts in tead of being reduced to 6-9 volts like a breaker point system. I would not use the feeder pole. Also in 1985 the 2.8 used an external voltage regulator and the 4.0 used an internal. The voltage regulator was on the drivers side fender well or fender mounted if I recall correctly.

steiner_5000 · Post by **steiner_5000** » Fri Feb 23, 2007 7:54 am

I went through some of the wires with my voltmeter and these are the results I got. There are 2 wires going down to the starter. A small one from the solenoid on the "S" post and then the big one coming straight off the battery. I volt metered the solenoid and found that 3 of the 4 posts had a constant 12 volt reading. The battery in, barttery out, and the "S" post had volts but the only one not to was the "I" post. Does this sound right? By the way I really appreciate you guys helping me out with this. I'm just about ready to tear my hair out over this project. So again thanks alot everybody!!!

DBrown · Post by **DBrown** » Sat Feb 24, 2007 1:31 pm

I would run the large power wire to the batt and hook it up to the side of the seloniod that the main power is hooked to, then just run the small wire from the firewall that tells the seloniod to kick straight to the small wire on the starter. I think that is how I had the starter in my 86 hooked up and that should get you to turn over.

this is how I got mine to finaly run right. I just attacked one problem at a time. first get the motor to crank then wire the ign. and so on....