Intermittent no start new symptom

[Chuck stallions]

Replaced bad starter. Now after the truck sits a few hours and I try to crank it i here a clicking type buzz under the dash truck seems to be spinning over fine. Also I've owned the truck since Sept of 2010 and the tach has never shown rpms while cranking but with new starter it does. About 300 cranking rpms when I hear the clicking type buzz. Both batteries are new 10 days old
Passanger batt shows 11 vdc while cranking driver batt drops below 10vdc. Went to have batts tested they showed good had alt tested shows bad diode but puts out 13.7 vdc charging. Can't figure out what that buzzing sound is GEM maybe. Truck is an 01 350

[NoRalPh]

Couple a things, First the tach has nothing to do with the starter. The difference is weather the CPS signal is sent to the tach or not. In an '01 (like yours) some do / some don't... Sometime in '01 the new, updated, instrument cluster was introduced that included a Trans Temp Gauge.

If yours doesn't have that gauge you're supposed to show cranking rpm on the tach. If it HAS that gauge you're not.

Both batteries are in parallel and I don't know how you could be seeing different voltages while cranking. Maybe it'd be a good idea to reevaluate all the connections and cables......

Take the cover off the fusepanel and put your hand on the relays there, one at a time, and see if you can't find one of them giving you that buzz, look especially at the IDM relay (303 maybe?).

Does it only buzz while cranking?

[Chuck stallions]

I have the old cluster no trans temp gauge. The only reason I associated the tach with the starter is it has never shown cranking rpms before until after I put the new starter on. I did an amp draw test last night both batts showed 2 tenths of an amp draw I assume that's the KAM causing that. Let the truck sit over night cranked it this morning no buzzing. Maybe I'm going crazy