The 75 and ZT Owners Club Forums - View Single Post

Keith · 7th December 2006, 14:04

Repairs :-

Motor
It is possible to dismantle a faulty motor by carefully bending and straightening the tabs on the back and removing the back plate. Normally it becomes immediately obvious that the brush attached to the black wire has worn down to the point where it loses contact and hence the motor stops, often though the other brushes are also jammed by carbon deposits in their brass holders. A replacement brush and a clean up of the holders, commutator etc will normally return many thousands of miles of life to the motor but a supplier of brushes has not yet been found so cannibalising old motors is currently the only source.
Please note a source for the brushes is now available, see this link:- http://www.the75andztclub.co.uk/foru...8&postcount=73
Some people have had limited success flushing the brushes in a fully assembled motor with WD40 although to be able to get the WD40 to where it matters i.e the back, the Motor should be removed as spraying through the grill is not adequate.

Be careful when dismantling and reassembling the motor not to dislodge the front bearing as any sideways movement could cause the fan to foul the shroud, dropping one as I did is not to be recommended!

Relays
Rarely one of the two or three Relays in the fan control box might fail in service
All the relays in the Rad fan control box are made by Tyco, they are Form A (on these quoted docs)
if the contacts look badly pitted replacing them whilst doing the motor is a good idea.

The relays are the same in Diesel and V6 Petrol I need verification re those in the 1.8

Big relay is V23134-B52-C642
http://catalog.tycoelectronics.com/T...%2052C642&I=13
and http://relays.tycoelectronics.com/datasheets/134.pdf

The two little relays are both V23073-B1005-A302 typical, I can't find them directly on the Tyco website but a google brings up this!
http://www.growtech.cn/admin/ProMgt/...5144750730.pdf

Almost any relay of a similar rating could be used in the petrol version as the box has lots of space but in the diesel the correct form factor is required to avoid having to wire them externally as the circuit board is designed to connect directly to the relay coils

Under bonnet fuse box Relay
This is a standard Relay and for testing could be swapped for any other similar coloured one in the car it only powers up the coils (and PWM circuit for the CDT) in the fan control relay box not the fan motor itself. if none of the relays in the fan control box can be heard clicking check this relay first.

Note The motor is hard wired to an large Fuseable link, expect smoke before that fuse ever blows!

Now the bit that matters a link to Howto get the Bumper off.

http://www.the75andztclub.co.uk/foru...read.php?t=204

The following posts contain some pictures of the various control boxes and Fan internals etc

7th December 2006, 14:04	#5
Keith This is my second home ZT400 Join Date: Oct 2006 Location: Ellesmere Posts: 5,948 Thanks: 0 Thanked 43 Times in 29 Posts	Repairs Repairs :- Motor It is possible to dismantle a faulty motor by carefully bending and straightening the tabs on the back and removing the back plate. Normally it becomes immediately obvious that the brush attached to the black wire has worn down to the point where it loses contact and hence the motor stops, often though the other brushes are also jammed by carbon deposits in their brass holders. A replacement brush and a clean up of the holders, commutator etc will normally return many thousands of miles of life to the motor but a supplier of brushes has not yet been found so cannibalising old motors is currently the only source. Please note a source for the brushes is now available, see this link:- http://www.the75andztclub.co.uk/foru...8&postcount=73 Some people have had limited success flushing the brushes in a fully assembled motor with WD40 although to be able to get the WD40 to where it matters i.e the back, the Motor should be removed as spraying through the grill is not adequate. Be careful when dismantling and reassembling the motor not to dislodge the front bearing as any sideways movement could cause the fan to foul the shroud, dropping one as I did is not to be recommended! Relays Rarely one of the two or three Relays in the fan control box might fail in service All the relays in the Rad fan control box are made by Tyco, they are Form A (on these quoted docs) if the contacts look badly pitted replacing them whilst doing the motor is a good idea. The relays are the same in Diesel and V6 Petrol I need verification re those in the 1.8 Big relay is V23134-B52-C642 http://catalog.tycoelectronics.com/T...%2052C642&I=13 and http://relays.tycoelectronics.com/datasheets/134.pdf The two little relays are both V23073-B1005-A302 typical, I can't find them directly on the Tyco website but a google brings up this! http://www.growtech.cn/admin/ProMgt/...5144750730.pdf Almost any relay of a similar rating could be used in the petrol version as the box has lots of space but in the diesel the correct form factor is required to avoid having to wire them externally as the circuit board is designed to connect directly to the relay coils Under bonnet fuse box Relay This is a standard Relay and for testing could be swapped for any other similar coloured one in the car it only powers up the coils (and PWM circuit for the CDT) in the fan control relay box not the fan motor itself. if none of the relays in the fan control box can be heard clicking check this relay first. Note The motor is hard wired to an large Fuseable link, expect smoke before that fuse ever blows! Now the bit that matters a link to Howto get the Bumper off. http://www.the75andztclub.co.uk/foru...read.php?t=204 The following posts contain some pictures of the various control boxes and Fan internals etc Last edited by GreyGhost; 4th August 2009 at 14:39..