Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Help with CVH starter

The selenoid is located on the top of the starter. This is a single unit. I went for the rebuilt because I wanted to keep all original parts on my 1985 Morgan.

Would have thought a model of that age would certainly have a small cube shaped starter relay which should make a faint click if operating. This sound will usually be masked though by the louder clunk from the piggy back starter solenoid which both engages starter pinion and applies power to starter motor itself. The old mechanics trick was to short between the two large terminals at back of starter with large blade screwdriver to bypass solenoid and prove starter itself spun.

If flat battery or poor earth connection is to blame solenoid would usually click in rapidly repeating fashion. You don't mention that happening so suspecting solenoid as you do would be a good first call. Bosch ones I know can be replaced individually but for Ford ones it may be simpler to replace whole unit.

Do an earth test first. I used a jump lead from the battery neg to the starter mounting bolt. That showed a poor earth. I replaced both front and rear earth straps (1993 4/4 with cvh). Clean all contacts at the motor.
Next try cleaning the starter especially if it has the piggyback solenoid on the starter body. It works by energising a lever that moves the motor gear to engage the flywheel ring teeth. With age it can get sticky. You and bench test the motor with battery connections if needed. It may also be a case of worn brushes in the motor. A DIY job or take it to an auto electric repairer.

As a general note, if you're bench testing the starter, clamp it or get a good grip as it can kick when energised (and fling itself on the floor and get damaged ... don't ask how I know! 🙂)

K

I have heard and read that a picture can be better than a thousand words, that perhaps being the case, rather than me rambling on at length as I tend to do, perhaps if you beam up the data available from the link below you will find all sorts of info on understanding the operation of a starter motor and associated circuits...? If you get stuck on anything, plenty of help here to assist the learning process..?

https://www.youtube.com/results?search_query=ford+cvh+starter+motor+tests

Good luck.

Well success

Connected jump lead to the starter bellhousing bolt and the negative battery terminal and the engined fired right up.

Can't see any convenient bolt holes but there's a handy rectangular chassis bracing plate nearby which I can drill for an earthing bolt. It's far enough away from the manifolds too.

Thanks for all the advice

Great to read you traced the problem to a poor earth, though is it the one from the battery to the bulkhead/chassis. or the one from the chassis to the engine/gearbox..? A clean up of the connections may be all that is necessary, Perhaps while you are at it, worthwhile to replace the earth lead you thought looked a bit ropey..?

I thought the battery earth to chassis braided strap looked a bit puny but then I'm used to bigger and more modern battery setups. The chassis stud the earth connected to was pretty corroded and I don't think it would survive an attempt to undo it. It worked well enough for the test I did.

I couldn't get under the car to comment on the gearbox earth. I couldn't see any earth strap around the starter motor area but the advice to run an earth from the upper starter mounting bolt to the chassis seemed a good idea.

Of course I forgot to check the size of the bolts - 17mm ?

Getting ready made cables seems somewhat difficult so I thought I'd invest in a crimping tool (Draper 64335 Crimping Tool) and make my own.

What size cable would you suggest? 16 or 25mm ? Since this is an additional earth I thought the 16 would be sufficient.

I intend to put a longer (M10?) bolt through the starter/bellhousing and connect a right-angle ring terminal onto the end with a locknut to secure it. The other end would be an M8 ring terminal secured to the chassis brace below the bulkhead.

If you look at the dimensions of the cable supplying the starter motor you will see that it is rather heavy, given the starter motor is the highest electrical load in the car... Logic would seem to hint that the earth lead to/from the engine to the chassis, would ideally be of similar dimensions as it has to carry the same amount of current for the starter motor to operate successfully..?

I would suggest to save you cash, that buying a crimping tool is rather costly, as you can buy ready made up earth leads from Halfords for less than the cost of a crimping tool...? Of course there may be even less costly earth options via the interweb..?

Before you fit the new lead, be sure to clean to bare metal either side of the earth lead connecting points on the engine /chassis you can paint or grease over the bolts/nuts/chassis engine both ends to reduce the risk of any bare metal exposed in the cleaning process from corrosion..?

Good luck in your choices

The Draper crimper is only £18 and I would probably have cause to use it more than once.

The problem with the Halfords leads are: a) they are a bit weedy and b) they are only M8. The starter mounting bolt is at least M10 so we're looking at a custom cable.

Digging around in my bookmarks I found ECS (Electrical Car Services). They can make up leads to order; in this case a 45cm long tinned copper cable with insulation and a right-angle M10 ring terminal and an M8 straight ring terminal is £14.28.

E.g. ECS Custom Cable

Pretty good value I think.