E23 Faulty Instruments

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   I have a really nice E23 1984 735iSe with all the bells and whistles including Buffalo hide interior. I have not had it long and it has a genuine 75,000 miles and drives really well. However, the speedo will work intermittently and occasionally the rev counter and MPG guage will die. They all come back on but I cannot find the fault. It is not the connection on the diff.  I have changed the 2 small batteries on the circuit board and thought that this would cure it..but no. I have had it to 2 separate BMW specialists but to no avail. Anyone got any ideas?  

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McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Topic: E23 Faulty Instruments Posted: 13-March-2006 at 05:01
	I have a really nice E23 1984 735iSe with all the bells and whistles including Buffalo hide interior. I have not had it long and it has a genuine 75,000 miles and drives really well. However, the speedo will work intermittently and occasionally the rev counter and MPG guage will die. They all come back on but I cannot find the fault. It is not the connection on the diff. I have changed the 2 small batteries on the circuit board and thought that this would cure it..but no. I have had it to 2 separate BMW specialists but to no avail. Anyone got any ideas?

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eta. Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II Joined: 21-October-2002 Location: United Kingdom Status: Offline Points: 599	Posted: 13-March-2006 at 05:42
	Are you sure the batteries are the correct type? There was a post somewhere about them - best to use ones with tags - I think Maplins sell them. It is possible the pcb has been damaged by the batteries leaking and has got a hairline crack. Have you checked all the tracks for continuity?

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 13-March-2006 at 06:32
	Hello Eta, Yes, I have checked the tracks and the batteries are fine and I only changed these this weekend. The problem has been this way for a few months, now. Oddly enough, when I remove the panel, check and clean and return it to the dash, all works fine for half an hour or so and then the speedo dies. On a longer run, the speedo can work all the time but the crusie control will work intermittently. In motorway stop-start the other day, the speedo, rev counter and MPG guage stopped. When we got to a clear section and started to run at 70mph all came back working again. By the way, the temp guage has always flickered or died, since I acquired the car.

eta. Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II Joined: 21-October-2002 Location: United Kingdom Status: Offline Points: 599	Posted: 13-March-2006 at 07:29
	I'm not technical, but as it is intermittent, then there has got to be a poor connection somewhere. More of the e23 experts will be along soon to give you better advice. BTW, welcome! Nice to have another e23 on board. I have a '86 model 735iASE.

bmw1066 Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II GOOD OLD E23 Joined: 16-January-2005 Location: West Sussex Nr Brighton Status: Offline Points: 1095	Posted: 13-March-2006 at 07:30
	Sounds like you have a iffe conection. Have had the same problom with mine. Sounds like a lovley car. Try hear www.bmw7resource.co.uk to were all the e23 nutters are hear. Like me Edited by bmw1066
	Mark 735 se 1982 RED BARON A E23 is for life not just for x-mas BMW e34 530 v8 Sport kit Spelling always Bad

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 13-March-2006 at 08:59
	Thanks to you all, I cannot find an iffy connection anywhere, although I do not rule it out. When i first bought the vehicle, it would take a mile or so fot the speedo to come to life. Now it can take an hour! Regards,

Drew540i Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II Available from all good newsagents! Joined: 15-August-2005 Location: The Mansfield Massive Status: Offline Points: 632	Posted: 13-March-2006 at 12:44
	Sounds like Fuse No.6 needs a clean up and the tangs tesnioning. I've had this on E23's in the past and it was always this. The later E23 has the same SI board as an E28 and I have a couple of good working ones.

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 13-March-2006 at 13:54
	Well, it isn't fuse number 6 either. I have just cleaned and tensioned the tangs and no joy. A swift wallop to the left hand side of the instrument panel and the speedo started again...then died. What is an SI board, by the way?

PaulS Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II East Anglia BMWCC Regional Chairman Joined: 03-July-2004 Location: Aylsham, Norfolk Status: Offline Points: 2516	Posted: 13-March-2006 at 14:10
	The SI board monitors all yor guages for the servicing lights I believe. These play up a lot on the older cars (my e28 was exactly the same). I had the problem of rev counter and speedo doing the same as yours and no temp guage. Ended up buying a known working cluster from another e28 and put my original speedo guage in to keep the mileage the same. All worked ok then. HTH Paul
	95 E34 530i V8 Auto Maldives Blue

M3AG Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II 7 series & e36 m3 registrar! (Madness) Joined: 17-October-2002 Location: Good Old Hertfordshire Status: Offline Points: 1644	Posted: 13-March-2006 at 14:22
	McOil Try a complete replacement PCB board, as it does sound like this is the problem. Some of the wiring does crack with age and heat, and the only way of knowing if it is the board is to replace it. As Drew said, e28/23's are interchangeable, and are fairly easy to locate. Just make sure it's from a 6 pot. AG Edited by M3AG

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 13-March-2006 at 15:44
	Great, I'll try that...does anyone have a replacement?? I have looked on e-bay to no avail...By the way, how did you get a picture of your car on the message? McOil

essjay2004 Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 08-March-2006 Location: Grmsby, Lincs Status: Offline Points: 2	Posted: 13-March-2006 at 15:51
	Hi, my sister had a 1988 535i with exactly the same problem. It was diagnosed as a cracked circuit card and finished up buying an instrument pod off eBay for �75 as a new one is quoted at �500 fitted! If you buy a used one, be sure the part numbers match exactly as the wiring loom connections vary from model to model. Hope this helps

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 13-March-2006 at 15:58
	Thanks, essjay, It looks like that is the way forward - new CB. �500 is a bit rich! i will definitely go the e-bay route or mybe someone on here has one.

PaulS Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II East Anglia BMWCC Regional Chairman Joined: 03-July-2004 Location: Aylsham, Norfolk Status: Offline Points: 2516	Posted: 13-March-2006 at 16:03
	McOil, first upload photo onto hosting site - I used www.bmwmovies.net which is free to register to. Have the forum site open and photo iste. Once uploaded right click on the photo and go to properties. Go to the link and right click 3 times to highlight the link. Then right click again and copy. Go to the forum window and go into your settings and go to your signature. Then put {img} then right click and press paste to put the link in, then {/img} after it. change the {} to [] so the forum codes work. HTH Paul
	95 E34 530i V8 Auto Maldives Blue

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 13-March-2006 at 16:06
	Thanks Paul.

PaulS Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II East Anglia BMWCC Regional Chairman Joined: 03-July-2004 Location: Aylsham, Norfolk Status: Offline Points: 2516	Posted: 13-March-2006 at 16:22
	No problem! Paul
	95 E34 530i V8 Auto Maldives Blue

Drew540i Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II Available from all good newsagents! Joined: 15-August-2005 Location: The Mansfield Massive Status: Offline Points: 632	Posted: 13-March-2006 at 16:36
	I have a good SI board in a 525e Auto. Works fine. The car is due for the chop in the next fortnight. I'd want �30 for it (yeah, I know we're not supposed to flog things here) but they are about �150-200 quid new. To be honest this could also be a problem with a wiring plug - pull the ones out of the cluster, spray a bit of proper contact cleaner (NOT WD40!!) and exercise the plugs - could cure it, you never know! P.M me if you want it, I could take it out and send it to you this week.

Doive Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Really Senior Member II Joined: 09-February-2005 Location: Clinging to a turbine, Hexham Status: Offline Points: 1212	Posted: 13-March-2006 at 19:12
	I currently have exactly the same fault on my 525e, econometer is knackered (probably for the best), rev counter will die about an hour into a journey and come back to life intermittently, speedo is reasonably reliable but can very occasionally fail to register. I know it's the batteries, they have likely leaked all over the board. Problem is the acid damages the ICs on the board as well, this can damage their functions or lead to dry joints and will cause strange readings. I have a good board out of my old eta, I'm in the process of replacing all the dash bulbs with LEDs and changing the batteries. Not a difficult job. I'd say yours is definitely the batteries damaging the board.
	1987 BMW 525e Lux Auto (sadly deceased) Get Firefox - Ditch Hopeless Inertnet Exploder www.doive.co.uk

McOil Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 13-March-2006 Location: Preston, Lancs Status: Offline Points: 8	Posted: 14-March-2006 at 09:51
	Hi Doive, If it were the batteries, it cannot be now as I changed them and they had not leaked. I am changing the PCB, now. Let's see....

PaulS Members Profile Send Private Message Find Members Posts Add to Buddy List Really Senior Member II East Anglia BMWCC Regional Chairman Joined: 03-July-2004 Location: Aylsham, Norfolk Status: Offline Points: 2516	Posted: 14-March-2006 at 10:47
	McOil, you have pm. Paul
	95 E34 530i V8 Auto Maldives Blue