Difficulty starting - battery problem?

[ECR]

Well it had most of the signs of a battery problem but it wasn't. The starter would spin up well some times but other times really struggled. I repeatedly charged the battery and checked with a tester that it was good but it still looked like a failing battery. I opened up the starter motor and cleaned all the solenoid contacts, I checked all the wiring and ensured that the earth was good. In the end, I took the starter motor off and had it checked over by a specialist.

The problem turned out to be that one of the two braided wires to the brushes on the motor had fractured and so the motor was effectively getting half current. Sometimes, the broken braid would reconnect and then the motor spun well. My starter is an offset motor from Ark motorsport and like most alternative starters is based on a Denso starter. It's one more thing to check if you have mysterious starting problems.

By the way, Ark apply hot melt glue to the braids to help prevent them fracturing due to vibration .....

 

[anthonym]

I had similar in Portugal in 2006. Both braids were fried by heat and vibration, they worked but reduced. Replacement fixed them.

[Wrightpayne]

My 21 year old K series has never had any starting issues (other than ignition switch failing).

Do we think a bit of pre emptive maintenance on the starter would be in order? Strip, clean, re-grease and new brushes. Anything else ?

[Jonathan Kay]

Do we think a bit of pre emptive maintenance on the starter would be in order? Strip, clean, re-grease and new brushes.

It's really helpful to have the fault and fix documented. But it doesn't seem to be very common. So I don't think I'll be doing that.

But many starters are eminently repairable and it would be smart for each of us to work out what we've actually got and what we'd do and where we'd send it.

Jonathan

[ECR]

It’s a toss up between “if it ain’t broke don’t fix it” and preemptive maintenance. If you’re mechanically competent then a strip down and clean solenoid and contacts would be useful but if not ( no disrespect intended) then leave well alone. As you don’t start the car every day the brushes are unlikely to have worn out

[anthonym]

I think... if the insides are at risk there will be external evidence to match. Specifically fried wires and connectors. Cars with extreme heat and vibration being high risk, such as my K R500. Cool cars like VVC SVs more likely to be just fine. 

 

Edit. Hot melt glue sounds like a verry good idea.