Crusader 8.1 - add warning gauge cluster and project update

could not get edits to save, post below

First off, I haven't been on here in a while but all is well. Mark was nice enough drop me and email and see if I had given up on the 8.1's and bought an RV instead

The short story is, it's been an odyssey getting these 8.1's (now fully rebuilt) ready to install. Of all things, I got hung up for weeks and weeks on an oil pan leak! The simplest things and probably the ONLY thing I couldn't address in the boat. I turned out to be the rear cap/block connection as the source. One is 100% ready to go, I threw a sheet over it and down to a punch list on the second one. In the meantime, I just got a deposit on my 454's yesterday and will be pulling those just after Labor Day.

One of the things I wanted to add with these newer engines is a warning light gauge cluster. I scored a pair of gauges and harnesses but cannot get them to power up outside of my powerprobe. One of my challenges is the wiring harness colors on the round 10 pin engine connector don't quite match any of the diagrams I have. I searched everywhere and the oldest 8.1 wiring (or any manuals for that matter) diagrams are around 2006/07.


I'm trying to test this now while I have the engines in the garage and before I commit to installing new gauges. I posted a quick video the other day if anyone has any thoughts. It looks like just a two wire connection. I think the ECM provides the data back to the gauge for the water, trans and oil pressure lights. If true, if I get the CEL to come on momemtarily with the IGN, I'm good.

Am I missing something simple here? On my test gauge panel, I have an IGN switch and a separate momentary START button. On the boat, it's a single two position switch combining these functions. I'm turning the IGN switch ON in the tests I've done so far. That activates the fuel pump and gauges only.

https://www.youtube.com/watch?v=SJbb...ature=youtu.be

thanks
Bob

Bob: I looked at the video and the frames that appear to be from a crusader pub, showing the wiring diagram (2 wires to the light module), look just like the wiring for the ECM-07 installation manual...I think your's are earlier so they won't have the CANBUS. My guess is you have the MEFI-4's and I haven't had time to see if that light module is compatible with the MEFI-4's...just my observations...

makomark said:

Bob: I looked at the video and the frames that appear to be from a crusader pub, showing the wiring diagram (2 wires to the light module), look just like the wiring for the ECM-07 installation manual...I think your's are earlier so they won't have the CANBUS. My guess is you have the MEFI-4's and I haven't had time to see if that light module is compatible with the MEFI-4's...just my observations...

Click to expand...

Ah, interesting and exactly why I wanted to get them working in the garage before I commited to drilling gauge holes @ the helm. For what it's worth, there's a guy I connnected with who has an '02 Tiara with original 8.1's. From the factory, he has individual LEDS with the same functions (labeled exactly the same as my gauge).

I know mine are early serial #'s if that makes a difference. I do have the MEFI 4 OBD scan port and that works with the scan tool just fine. I haven't been able to find any wiring diagrams pre '06/'07. If you are anyone else has something, that would be a big help.

thanks
Bob

I dug thru some of my library and found the MEFI-4 does use a CANBUS but for the master slave connection, not for the diagnostic tool...

I will email you one of the manuals I have for an 8.1L w/ the MEFI-4....I'm certain Crusader uses what GM supplied; its the 'optional items' that would be missing from that manual. I'd say you can look at the ECU connections and figure out if you have any wires on the 'indicator outputs' and then go from there...

Just to close out this thread for the future searches. It is a little confusing on these older 8.1’s as Mark points out above. Mine DID have unused connectors so it was in fact plug and play all along. Thanks to Rick @ Line Six who got me on the right path. Adding these has nothing to do with the round/ten pin connector but as luck would have it, there are references to a CEL/ DATA OUTPUT for the unused wires. That, plus a diagram showing a splice into the ten pin got me down the rabbit hole. Plug in each and the unused purple wire is switched power. There was zero chance of me figuring this out, I wasn’t even close.

If you have 8.1’s and no warning lights, this is a great upgrade but find the gauges and harnesses while you can!

Bob