Stereo install now tach not working. Coincidence?

[danielmp]

Just finished a complete stereo install on my '90 325i. The car had a cheap aftermarket headunit which was somehow still wired through the factory premium amp. When I pulled the headunit, there was a rat's nest of speaker wires crossing between the headunit and the factory amp wiring. I pretty much cut the whole mess out since I was running new speaker wiring. I put a new amp, headunit, front and rear component speakers, 10"sub, and ran all new speaker wire. The stereo sounds great, everything works including dimmer control on the headunit and the antennae control but now my tachometer and MPG gauges are doing nothing. Speedometer, odometer, coolant temp are all fine, gauge illumination is fine. Nothing else in the car is affected. Could I have cause this with my install or is it likely a coincidence?


Install details:
Headunit - Kenwood KDC 994
Ran new fused constant power wire directly from the battery terminal
Connected into the factory ground (BN/BK)
Connected into the factory ignition wire (VT/GY)
Connected into the factory dimmer control (GY/RD)
Connected into the factory antenna control (WT)
Ran a new remote amp control wire
Ran RCAs to the amp in the trunk

Amp - Alpine PDX5
ran power and ground cables directly to the battery power terminal and the factory ground next to the battery

Any help would be greatly appreciated.

[StereoInstaller1]

Have you downloaded the ETM yet so you can see what is what in the wiring?

[Highway1]

Check your fuses ;)

Sent from my HD7 using Board Express

[danielmp]

Yes I have the ETM and I have checked the fuses. Thanks for the brilliant help guys.

[Dominic49]

Yes I have the ETM and I have checked the fuses. Thanks for the brilliant help guys.

or you can be a sarcastic douchebag, thats sure to get you a bunch of help

start with the basics before assuming the worst we cant help you to step 9 if we don't know you first went through 1-8

[danielmp]

I think the sarcasm started before my comment. Anyway, the fuses are all good. From the ETM looks like fuses 10 and 21 would be the only ones with any impact on the tach. Fuse 10 supplies the tach and all of the Fuse 10 wires are GN/WT. I know I didn't come near any GN/WT wires. Also, it seems if it was a power issue I would have other symptoms with the SI board and so far the tach/mpg is the only thing not working, SI board appears to be fine as LED lights are coming on at start. (all other fuse 10 functions are fine like check engine lights, reverse lights, seatbelt timer, etc) I guess I could have caused a faulty ground somehow from the tach but looking at the ETM I can't find any ground points from the tach that are near the stereo install area.

I'm thinking now that the actual tach gauge coincidentally went out at the time of my stereo install cause my SI board appears to be good. I don't have a lot of experience using the ETM so I could be missing something. I have a good cluster in my other car, '88 vert. so I may just swap the two this weekend to see if it's a cluster issue or a wiring issue. It's kind of a pain in the ass to do that, but if I have to pull the faulty cluster anyway to get the voltmeter back there to start diagnosing things then the diagnosis might be easier if I just pull 2 clusters and temporarily swap them.

I don't mean to be an ass so excuse the sarcasm. Let me know if you guys have any other suggestions to try before swapping clusters. Thanks for the help.