Cab electric horseshoe not lifting - UPDATE 2 - FIXED!!

Post Tue Apr 24, 2012 7:44 am

Morning All,

I have an electric hood on my cab, but in the past, only the horseshoe has opened electrically - the rest of the mechanism is bust and disconnected, which I can live with. However, the horseshoe motor isn't doing anything now - totally dead - no noises or anything.

Where should I start looking?

Post Mon Apr 30, 2012 12:38 pm

It's not often that a technical query gets no responses, so I'm giving this a shameless bump in the hope someone can help me. Summer's coming (believe it or not!).

Post Mon Apr 30, 2012 3:58 pm

I don't think there's enough knowledge about to answer questions relating to electrical hood problems, Pete. I presume you have checked the fuses. There are also some connectors in the boot (remove the moulded cover) you could check to see if you're getting a current to the motor.

I could be a micro-switch problem. Is the hood pushed back before you start the auto opening sequence?

I hope someone comes along and answers your question better than I could.

Post Mon Apr 30, 2012 10:03 pm

Check that the levers that operate the roof (rather than the horseshoe) haven't been moved. Moving these trips the micro switch to operate the hood motor rather than the horseshoe one as both can't have power at the same time. If this doesn't work try with a multimeter to see if there is power to the horseshoe motor.
Could also be the ecu for the roof which can corrode inside.

Post Tue May 01, 2012 12:51 pm

Thanks for the advice guys. When the weather eventually improves, I'll look into this further.

ben9040 wrote:Could also be the ecu for the roof which can corrode inside.

Where is this ECU?

Post Tue May 01, 2012 12:53 pm

This page has a document about fitting the electro mechanila roof.

http://www.ow.no/index.php?option=com_wrapper&Itemid=34

Might give you some pointers.

Ben

Post Tue May 01, 2012 1:05 pm

ben9040 wrote:Check that the levers that operate the roof (rather than the horseshoe) haven't been moved. Moving these trips the micro switch to operate the hood motor rather than the horseshoe one as both can't have power at the same time. If this doesn't work try with a multimeter to see if there is power to the horseshoe motor.

This ^

Completely disengage the main drive motor so it swings out of the way and try to move the drive into the gearing slightly, this could be enough to trigger the microswitch and get the mot motor working again. Alternatively disconnect the plug that goes to each of the main motor micro switches and join the terminals together on the plug on the ECU side with a short piece of wire (effectively doing the mictroswitches job). One or both of these shorted out should make the top cover work if the ECU isn't faulty.

Post Thu May 24, 2012 9:57 pm

Resurrecting my old thread on this problem as I've had more of a play with it tonight. (Now the hot weather has arrived at long last, I am of course keen to get the hood down!)

I think something has broken altogether now as the two switches on the dash don't do anything now - no whizzes or whirrs - nothing at all. I've tried disengaging both motors, turning them a bit then re-engaging one at a time, but I can't get a peep out of either motor. I got the ECU out and opened it up - nothing obvious in there - clean as new. I've poked about in the microswitch at the top of the screen to ensure that isn't jammed, but I can hear it click on and off as I stick a pencil in, so I assume that's working ok. Seems like something somewhere is telling the ECU not to do anything.

I did note that one of the wire cables to the boot hinge (drivers side) had snapped, but on removal of the surprisingly complicated, housing underneath that it feeds into, I found that this is entirely mechanical - just seems to make sure the boot is closed when the horseshoe goes up to prevent them clashing.

Any other ideas??

Post Fri May 25, 2012 11:10 pm

Right, POETS day today and as the sun was still shining, I set about sorting my hood out before the summer disappears! I worked through the wiring diagram, usefully provided in the wiki (http://www.e30zone.net/e30zonewiki/imag ... le_Top.pdf), first confirming all relevant the fuses were intact, then checking the ground and power connections to the control unit, then confirming that the control switches on the dash were getting through to the control unit - all good so far.

Then I moved on to the two micro-switches that sit around a cam on the horseshoe motor, which I managed to work out weren't set up right - they weren't signalling to the control unit at the appropriate places. So, after much mucking about, adjusting the lever that attaches the cam in the stowage area to the horseshoe (by winding/unwinding the thread on one end of the lever, having released it from the horseshoe first) and also by the cleverly provided adjustment screw on the motor cover plate, I got both the open and closed position switches to work at the right times. I was also able to improve the way the horseshoe clamps down in the closed position by these adjustments. Anyway, this still didn't fix my problem of making the horseshoe motor work.

The horseshoe motor. The two blue & brown wires go to the two micro-switches under the removable plate. The adjustment screw is circled red.

The cam/lever inside the stowage area. By adjusting the screw thread on the lever (circled red), I was able to improve the position that the micro-switches kicked in, but also get the horseshoe to sit down better.

So, next on the list were the other two micro switches (noted as I and II on the wiring diagram) which are located behind the roof motor. Checking operation of these showed that neither were operating. I found that these were operated by the position of the cam lever in the stowage area that lifts/lowers the hood - well, they're supposed to if it hasn't all sheared off like mine! Anyway, with the motor disengaged, I was able to rotate this cam and see both micro-switches operate at different positions. So, with a little trial and error, I eventually found the position that gave the right signals to the control unit to enable the horseshoe motor to operate. And that was all it was - that cam in the stowage area had obviously just been knocked out of position slightly, operating one of the two micro-switches, that told the control unit that the hood wasn't in the right position for the horseshoe motor to kick in.

The culprit - moving this cam lever a little sorted the problem

A lot of time spent for a very simple fix, but I'm really pleased, plus I know a lot more about how the whole mechanism works now, so I'm well chuffed. So much so in fact, that I'm going to attempt to restore the entire hood back to full electrical operation now, using one of the repair plates available on eBay. In preparation for this, I degreased/cleaned every single moving joint in the entire hood mechanism (there are loads!!), then lubricated them again with spray grease and finally worked the hood back and forth manually loads of time for it all to soak in, resulting in a very smooth and easy operation. Should make lighter work for the motor when I eventually get it sorted. I feel another tech' article for the wiki coming soon.

So inspired I was by my success, I gave the car a good wash'n'polish tonight, ready to go cruising tomorrow in the sunshine - with the hood down!!

Happy days.

Post Sat May 26, 2012 9:38 am

Well done. I need to have a look at mine now that the weather is warmer. I don't think my problem is going to be as difficult as yours to resolve as my hood worked fine before the cam in the storage compartment slipped and bent the main lifting arm.

I disconnected the motors and have been having problems getting them to work since. This I feel is minor (famous last words) so hope to sort it quickly. Cleaning and regreasing all the hinges is a great idea too so I will start by doing that first.

Many thanks for your thread and advice

Post Sat May 26, 2012 12:12 pm

Nice work Pete...you should do a piece for the Wiki.

Post Sat May 26, 2012 9:55 pm

aimlessrock wrote:Nice work Pete...you should do a piece for the Wiki.

If/when I get the whole mechanism done, I will.

Post Mon May 28, 2012 9:50 pm

I did some research, the age of the motors is now an issue, turns out the motor casings are made of some alloy compound that does not weld, and actuating the button to go in the opposite direction, mid lift, puts additional stress on the motor casing, this coupled with the age, shears off the top of the housing.

I bought this plate..

http://www.ebay.co.uk/itm/190684305470? ... 1558.l2649

Simply because of the full money back guarantee (including postage) if I was not happy, it took an half an hour to fit, and cured the problem.

Seller knew his stuff, was more than happy to answer questions.

Roofplates work, old alloy casings suck.

Post Tue May 29, 2012 7:29 am

Nice one! Did you have any problems setting it all up after fitting the plate? Could you post some photos of it all installed as I'm not 100% on how it all fits together yet.

Post Sat Jun 02, 2012 8:42 am

Hi, no problems fitting the kit and it worked fine, i'm told micro switches can be a problem if they are moved though.

I supported motor in the boot, undid allen bolts, added plate, tightened new allen bolts, fitted cam and centre bolts, connected arms, and voila, one working roof.

I don't have pictures, but listing picture 3 shows it all connected up.