[thelvis1]

Having an issue with my 1997 740il. Not getting power to the ignition where my cluster panel isn't displaying information to start vehicle. Checked fuses and replaced ignition switch and nothing. Any help would be greatly appreciated

 

[u.nanimous]

You're new here so I have to ask...how long have you had the car?

Did you check ALL the fuses? Under the hood, above the battery...under the passenger seat?

Be patient, we have an electrical expert that is on here every few days who can probably help you figure this out.

Welcome to the 'fest and good luck!

 

[thelvis1]

Thanks. Had "Goldielocks" for 2 years. A restoration project. Hopefully your buddy can help me pinpoint the problem.

 

[u.nanimous]

I would have thought he'd seen this by now and offered some help...maybe it just needs a little - BUMP!

 

[thelvis1]

Okay, I'll try bumping the starter

 

[u.nanimous]

I meant bumping the thread so it is closer to the top of the list.

 

[Mayorchuck]

Are you saying the gear selection is not displaying on the cluster? If so, did it happen after you washed the undercarriage or after a rain storm? I ask because the transmission position switch, aka by other names such as transmission neutral switch, is known to get water inside and cause this issue. It is located on the drivers side of the transmission. There are DIY's on a couple of forums if you do a search.

 

[thelvis1]

ignition/ no start issue

No, didn't wash undercarriage but will check neutral switch. I was told about a strap fuse, but where is it? I can't locate

 

[Mayorchuck]

Never heard of it.

 

[thelvis1]

I'm at a loss, trying to diagnose before towing to the dealer.

 

[thelvis1]

What fuse/relay would send power to that portion of instrument.cluster to complete circuit?

 

[Mayorchuck]

No fuse. Lights are handled by the Light Control Module but it's not a illumination issue. The DME is not getting the signal the car is in gear. Fuse 22 powers the selector/range/gear (pick a name) switch. You know, there has been a few of these that has been caused by the oil level sensor. It is on the same fuse/circuit. Unplugging it has resolved the issue. I believe it sits on top of the left side of the oil pan. It may or may not be causing the fuse to blow.

 

[QSilver7]

Having an issue with my 1997 740il.

Not getting power to the ignition where my cluster panel isn't displaying information to start vehicle.

(??? I don't understand what this means)

... I was told about a strap fuse, but where is it? I can't locate

(???I don't understand what this means)

What fuse/relay would send power to that portion of instrument.cluster to complete circuit?

May I ask for a different explanation or wording (if possible) of some of the things that have been written. They aren't making sense to me...and perhaps to others, too.

The communication bus for your e38 is a lot different than your e28. There is communication going multiple ways from major control modules over a "bus"...this cut down on the amount of wiring required in the car.

The 20 digit alpha/numeric display in the instrument cluster receives data from the LCM (in regards to the check control priority 1 & 2 warnings). That display is also has first priority to the Check Control System. The OBC, CLOCK, and AUDIO can send things to that display...but will be wiped out by the check control system since it has first priority.

Again, it's not clear (at least to me) what the issue is that you're having with the instrument cluster. Like, does it not put up ANY warnings from check control? How about the OBC & AUDIO...does any data from those components send data to the cluster's display?

There's also the button on the right side of the display (the CC {check control} button) that can call up info on the display. What happens if you press & hold the right button? Do you get the message CHECK CONTROL OK?

How about if you try to program the OBC features to appear in the cluster's display...if you press & hold the BC button on the tip of the turn stalk indicator...does PROG? appear in the cluster's display?

If the check control system isn't sending data to the cluster's display...then that would point to the LCM. That is the component that sends the check control warnings to the IKE (instrument cluster display).

Also, do to the clusters having pixel issues...you can safely say that the cluster hasn't been changed, right? If it has, was it coded to the vehicle?

Again, there's so much that's unclear...help us help you better and fill in as much as possible so that we can get an idea of what the issue is...that will lead to better suggestions or directions from the forum.

 

[thelvis1]

None of the l.e.d. indicator lights come on or check systems. As stated, the car isn't getting power. New battery and ignition switch still won't fire

 

[Mayorchuck]

That's different. If it were mine, I would check the ground from the (-) battery terminal. From there check the main fuses above and forward from the battery. From there, the main feed goes under the passenger seat, the lowest point of the floor pan that is perfect for holding water from sunroof drains that leak. That fuse block feeds the various fuses in the ebox.

 

[GMCPaul]

No fuse. Lights are handled by the Light Control Module but it's not a illumination issue. The DME is not getting the signal the car is in gear. Fuse 22 powers the selector/range/gear (pick a name) switch. You know, there has been a few of these that has been caused by the oil level sensor. It is on the same fuse/circuit. Unplugging it has resolved the issue. I believe it sits on top of the left side of the oil pan. It may or may not be causing the fuse to blow.

When the oil pressure switch which is located on the passenger side front bottom of oil pan fails it blows fuse 22 under the hood and vehicle does not start due to DME being unable to read the gear selector switch which as the Mayor said is also served by Fuse 22, so if fuse 22 is good it's not the oil pressure switch.
Paul