Engine/Transmission (1994 - 1998) Hard starting "97

[donhoward]

I’m having trouble with my ’97 on start up, usually in the morning, but only occasionally. When I key the starter it sounds like the batteries are almost dead and the motor barely turns over. The engine starts right away and runs fine but this hard to turn over thing is a little worrysome. This usually only happens on during the first start up of the day. I’ve replaced both batteries, cleaned all battery terminals and grounds, replaced the starter contacts and plunger with a Larry B’s kit, and checked for fault codes (none). Does anyone have any suggestions?

 

[K5IP]

If it were mine, I would check the battery terminal voltage under starting load and compair the voltage under the two different start conditions. If the terminal voltage is much lower when the fault occurs, I would assume the starter is drawing more current. High current conditions can occur if worn starter motor bearings are allowing the armature to rub against the field structure. Winding shorts could also cause this but would have a more consistant failure.

If bearings are a problem, replacing them is not usually too difficult.

Rog

 

[donhoward]

Thanks, I'll rig up a meter in the cab and watch voltages while starting. How about the starter relay, could that be the problem?

 

[K5IP]

donhoward,

I doubt that the relay is the problem. As long as it is allowing the main starter contactor to be pulled in, it is probably ok.

I should also have mentioned a second failure condition. If you find the battery terminal voltage to be higer in the faile mode (as opposed to lower) it would indicate that your starter is drawing less current (nominal is about 500 to 700 A), which could indicate brushes have been worn.

Unfortunately I may have been incorrect in saying these things are easily repairable. I am looking through my service manual and no breakdown info is given, they only say to replace. I suspect this may not be the case, but I'am not sure.

Rog

 

[donhoward]

Thanks again. Either way it looks like the starter will need to be replaced. The truck has 165,00 on it and this is the original starter. It has had what I would consider easy service and everything I have read indicates that these starters can go through two or three sets of contacts before the unit needs to be replaced. Thanks again for your help.