Once you find your meter, do as Onkel Udo suggested. At least this way you can divide the system between the stuff in the instrument panel and the stuff in the alternator. Then you will know which place to look for the problem.
--
Art Benstein near Baltimore

Time flies like an arrow. Fruit flies like a banana.

My HVAC guy is here and I asked to borrow his VOM.

I found that the battery is reading 12.4v and after starting the car it remains exactly that.

I find it hard to believe that replacing the regulator/brush assembly on the original alternator and the replacement I put on are both dead. However, putting the meter between the positive lug on the alternator and the ground shows no voltage.

What should that setup read on a good alternator?

Randy

Like oldduke says, get your multimeter and test the output on a cold engine. As oldduke says on the voltage output.

When you say you replaced the brush assembly, oh, I see, on the starter motor of your 1990 Volvo 740 estate / wagon.

You replaced the:
• large copper brushes on the starter motor, or
• the starter motor brushes.

I was confused and though you meant the alternator brushes. D'oh!

It would not hurt to perform a full check of starting and charging. Though the problem could be in the solenoid as a mistake to the repair in the solenoid (I've done it). You used quality and not after market brushes for the presumably Bosch starter motor, or another model?

As for charging faults, you may want to check this first. Harbor Freight sells cheap, cheap, cheap multimeters that work ok for like 7$.

• Agree Dan and Onkel and oldduke with conductor as ground from the alternator body to the engine block. The braided conductor can fray and break sometime at or in the ring terminal insulators. Use braided copper conductor or a strong stranded conductor of a proper insulation temp rating for under the auto hood. Does not hurt to up the factory conductor by one gauge, considering the current. Though I see the alternator ground conductor on 240 as a size too small.
• New brush ends on a worn slip ring interface? If the alternator is also 200k. Doubtful, unless rebuilt.
• Presuming you merely replaced the brushes on the alternator brush carrier or voltage regulator ... New brushes are Bosch or OEM to your alternator brand? You allowed enough brush length to secure contact the slip rings?
• Failing voltage regulator, if as many miles as your 1990 745.
• Failing one or more field coil windings in the stator or rotor (armature?)
• Battery cable on battery posts secure and free of corrosion? B+ conductor from B+ on battery post and conductor from starter motor to alternator B+.
• Check the excite D+ connection.

Here we have the Volvo 700-900-90 series FAQ hosted right here on your mighty brickboard.com, with the topic on starting and charging:

https://www.brickboard.com/FAQ/700-900/ElectricalStarting.htm

If you checks on the charging system do not work out, perhaps pull the starter again and check for faults or shorts that should not be there.

You have service manuals? We do have:

http://www.volvowiringdiagrams.com/?dir=volvo/740%20Wiring%20Diagrams

As for the starter motor or alternator internal electrics, use your experience or fins wiring diagrams specific to the starter motor and alternator.

For some Volvo OEM factory green manuuals, try:
http://www.volvotips.com/

Be certain you use the most modern browser version, pop-ups DISABLED, the most current media runtime Volvo Tip's uses. Do not let Flash or Shockwave media runtimes store data on the drive. Adobe refuses to make a secure media runtime. So Mozilla balks.

Download drivers from the OEM source ONLY, never third party sites.

Hope that helps.

Back to writing cover letters for jobs. yay.

Thanks,

The Sleeping Pill (Benardryl) Works Best the following Morning. Like Now.
--
The Volvo 164: The Mightiest of All Volvo Automobiles in Perpetuity