951 won't start

[smallinson]

I have a 87 951, and recently I've had some trouble starting it. Turn the key, nothing - headlights dim to nothing so something is obviously drawing a lot of juice. After doing this for a while, there's occasionally a slow crank which is enough to get it to fire. The battery has been trickle charged and seems OK. My thoughts were dirty commutator on the starter motor or maybe a dodgy solenoid. Any other ideas?

[wvicary]

Do a amp draw test on the starter or just have it replaced/rebuilt. Also inspect the main ground cables near the battery and from chassis to engine block. I often just replace these items due to age and eliminate them as causes.