Main Fuse Problem?

[leebee]

Update: Fitted another starter motor today. Tried it first on push button switch with and ammeter connected to main starter cable.

As we wound the engine over with ignition off it was drawing 290 amps for the first four checks. However on the every fifth or sixth turn of the key the ammeter would go off the scale over 400amp limit. This is obviously the reason for the main fuse blowing ( and subsequently the starter brushes when the main fuse id bridged out).

Problem is - what is causing this massive overload as the van is very reliable and starts quickly on the turn of a key? All pulleys are running free - I also wired up a test light to the start side of the solenoid to ensure the engine wasn't running with the engine, which it is not.

We are at a loss with this one? Any advice welcome?

[ake]

Check every electrical connection between starter and battery is tight, a poor connection will cause a higher load because of the resistance

[leebee]

All connections are tight. We are trying to get hold of a higher rated ammeter to check how much above 400amps it is intermittently pulling. Also trying a different make of starter brushes in case original replacements were a faulty batch. Just can't figure out why on first few spins it pulls 290amps and then the odd spin after that it goes off the gauge when cranking. The van was used for 6 months without fault prior to this main fuse/starter problem - now it appears that the main fuse or brush wires could blow at any time. Changed alternator, starter, battery and had the engine bay wiring harness off for visual inspection - it is now just an expensive 2007 high top storage shed!

[whitemice]

Wondering whether there is something dodgy going on with the ignition switch. ie. it is INTERMITTENTLY allowing the starter to remain ON.

The earth from the starter has to be REAL good or current will go HIGH. Worth replacing with or adding another BIG wire DIRECTLY to battery negative rather than relying on engine mounts for the HIGHEST load of system to find earth.

The main BATTERY positive cable HAS to be real good ie. ABSOLUTELY NO INTERMITTENT contact/shorting.

Is solenoid wiring connected correctly as SMALL current/heat knackered brushes WILL occur otherwise?(check by disconnecting earth of starter and then reconnect just by touching to see that there is no small spark with ign. on.

[Davidcity]

Hello, I hope you are well. I am having a similar issue with my transit, blown battery fuse twice and was wondering if you found the cause of the problem ?