Starter issue... or not?
 

I go to start our 1994 Buick regal and every other time it will not start. It will not start after driving it for a while aka when its hot.

When it does not start I can get 5.5 volts from the blue wire connected to the solenoid. When the key is turned I can hear it thunking. The big wire going to the starter is getting 12volts. could the starter acting up be a symptom of the 5.5 volt issue.

Any thoughts

1994 buick regal
100,000 miles
3.8 liter
battery has 12.5 volts

Check the power connection going to the power distribution block right next to the battery. Mine was loose at one point and caused me all kinds of issues, including no crank, low voltage reading, abs issues, etc.

Anyone know where the starer relay is on this as well?

If it has one, I think it will be in that same distribution block.

On top of the starter (I think).

"Blue wire" to the starter solenoid? It's usually a purple wire to the starter solenoid...

Yes the blue wire...I'm color blind.

I cleaned up all the connections I could find, retested the system and I get 12 volts to the started in every way.

So I figured the starter was bad. I replaced it and it is still happening.

The only solution I have found is to pop the hood and let it cool for 10 min.

Any ideas?

I would doublecheck the blue wire to make sure it will light a test light. The only other possibility is a bad ground, which I believe the primary ground is by the ICM.

It hasm relay as you say
in this box witth in englich
is marked crank #11
in dis fuse relay box
lookets for this relay
is gravs in colors\
mays yous is same
butts itsss marked
crank nots on top of de
starter de starter solonoids
on topps of de starters

How old is your battery? Perform a load test to determine the problem. Solenoid could also be the culprit.