What is wiring diagram of 1990 Chevy suburban starter I have three wires two go on the big post coming out of the soleniod one attached to the small post on the soleniod cart wont turn over

place the starter in a good vice or clamp it securely to a bench
attach the ground wire from the battery to the mounting flange of the starter body
attach the positive terminal to the positive terminal big terminal post that has no wire going inside the housing
touch the very small terminal to the positive terminal post to energize the solenoid and spin the starter
the body has to be firmly clamped or the motor will spin off the bench

There are three posts on the starter solenoid. Two large ones, and one small one. One of the large ones has a braided wire going into the starter. leave this one alone. On the other large ones, you will connect the positive battery cable as well as the large red wire coming from the alternator. The small purple wire connects to the small post on the solenoid. Lastly, on the engine block pointing the opposite way (towards the drivers side) is another stud and you will connect the negative battery cable to it.
Make sure that none of the wires can touch the other posts coming out of the solenoid.


4: Negative Battery Cable
6: Purple Starter actuator wire - 12V when key turned to start.
9: Positive Battery Cable
10: Positive Cable from Alternator

Well, according to my diagrams for 88-94 models, the alternator only uses the red and brown. There are pink-black wires that power some of the sensors and solenoids but should go to a fuse marked ECM in the fuse box.
Have you tried hooking up the harness without using the pink-black wire ?

Take negative off battery post. Take off big end of cable from starter. and the small solenoid wire. Two bolts hold starter on (some cars use three bolts). Take them out and starter is free. Reverse procedure to install new starter.

Good luck.

OK, There should not be a "Tan" wire there. It is probably the "Red" or "Orange" wire that has faded real bad and just looks tan. It goes on the same post as the large black battery cable. It should be a 10 gauge wire. The other end of that wire goes to the "BAT" terminal on the alternator. (in case you want to check and make sure) The smaller black wires should be ground wires, They will attach to the transmission housing. Usually, there is a special bolt with a stud made on the end of it and a nut that secures the wires. As you said, the purple wire goes to the small post on the starter solenoid.

On the battery side should be the blk/org (alternator wire) and yel/blk-w/fusible link with of course the positive battery cable, On the other big terminal should be the other yellows, for your small terminal marked with an "i" should be the red/blue if it has the small terminal, if not on the big terminal opposite of the battery.

you have three post on the solenoid 2 big and 1 small 1 big connects directly to starter motor the other big gets direct battery power the little one is ignition (concidrably smaler wire) hope this helps be sure to double check all connections and grounds

Doesn't sound right. Black wire should be attached to negative battery terminal. If cable is large, it might be the ground wire to the starter. Must be attached to the starter with nut on post. The starter will also have a big red wire connected. This wire is hot, and is connected to the starter motor when the solenoid closes (when you turn the key to start, the small wire to the solenoid supplies 12 volts to engage the solenoid).

most of the time all big hole wires go to the big post whitch would be battery an hot leads.the smaller wire sould go to the s post closer to the block. s stands for start.. GOOD LUCK

It's just an old Chevy starter! On that round starter solenoid, you will see two or three posts. One thick copper post, and one or two small
steel ones. The thick copper post you can't miss. It's about as thick as your little finger. The one, or two, small terminals, (Posts), are the thickness of a ball point pin refill.

You should have the Positive cable that comes down from the battery, connected to the thick post. There should -> also be two or three wires in a small wire loom, that connect to this post. This small wire loom will have a metal round terminal, that has a hole in it, large enough to go over this post. The battery cable goes on first, then this small wire loom terminal. Then a lock washer, and a brass nut.

If you have a solenoid with two small terminals, in the solenoid itself, next to the small posts, you may see -> ST,
and -> R. There should be a single wire, that comes down out of a wiring harness. It will have a round metal terminal end on it, and a hole in it, just large enough to slip over the small post. You want to connect it to the post with -> ST

All that is going on here, is that the solenoid is a magnetic switch.
If it wasn't present, you would have a thick wire, like that battery cable, going up to your ignition key switch. Instead you have a real small wire going to it.

Electricity for other circuits, like the lighting circuit, heat and air circuit, and so on, get their supply from the large solenoid post, also. That's what that two, or three wire, harness is for.

ST stands for Start. This is the Start side of the solenoid. R stands for Resistor. There was a wire used to connect to this small post, and it led up to a resistor mounted on the firewall, of older cars. These cars used a distributor with points in it. A wire went from the resistor over to the distributor.

Your solenoid may not have two small posts. It may just have one, with ST next to it, Or -> S