Starter motor / solenoid

[Spike]

OK brains trust
History - had the van unstarted for about 2 months, started fine off the key [ the battery is quite new ] drove for about 1 hr left standing for about 15 min and it sounded slow off the key but started ok, drove for about 30 min stopped for 3-4 hrs and slow off the key again but started, left standing for about 10 min and then all l got was very slow motor turning off the key and it was roll start time !! and now that is all l get. Charging is ok and bat v is good. all connections are tight.
my question is could the problem be the contacts inside the solenoid?
should my next move be to bypass the solenoid and put 12v direct to the starter and if successful will this confirm my suspicions
cheers

[pj350]

It does sound like a charging issue ..
Could try shorting out the solenoid with a screwdriver...
would tell you if that is a problem.

[damienengland]

I don't generally connect slow cranking with a solenoid issue. Can you try swapping batteries temporarily to eliminate the battery as cause? I think the solenoid engages the drive gear, so bypassing probably won't give the same load conditions as cranking.

[Sandaro]

Check coil maybe. If it is burning hot to touch when you're getting slow start may be on way out.

[Innuendo]

Slow cranking can be caused by heat or voltage drop when hot. Running a relay to the solenoid can help.
I would be taking a reading of the voltage to the solenoid on crank cold and then hot.

[wbute]

I suggest that it would either be dodgy battery leads/battery or connections. Or it’s just worn out. The solenoid usually just won’t throw the starter motor into gear and just clicks.
I had a Kenworth with a 14 litre Cummins that had 4 N70 batteries trying to drive the starter motor. It was always a slow cranked especially in winter. In the end I could get it to start and got the auto sparky to look at it. Turned out it had a braided earth lead between the engine and chassis. It broke. But when he replaced it with a new insulated earth lead the cranking speed went back to what it should have been.

[Innuendo]

Earth lead is a good suggestion. Look for an engine earth lead (block to chassis) don't simply rely on the battery earth.

[Spike]

OK, problem seems to be solved, this is the process l followed but am unsure how l arrived at a successful ending.
l have an earth lead from bat neg to alternator brkt bolt and 1 from bat neg to the radiator support. l removed both and cleaned / sanded connection point, still just running very slow off the key. Next l thought l would test the integrity of either. l removed the lead that goes to the engine / alt bolt, still the same,re connected and then removed the lead that goes to the rad support. BINGO started like a champ ! Tried it a few times, warmed everything up, started it a few more times, all OK. Re connected the bat neg cable to the rad support and it starts fine. Out for a drive and a few stop starts and all OK. So l will be stuffed if l know......a dodgy earth somewhere? Thank you for every ones input, cheers