Kroon Harness Installation

[Tom]

Thanks for this thread, Tom. It's going to be very helpful as I just ordered one of these harnesses for our 951 since the exchange rate is currently pretty good. I added the MAF option, which includes a switched, unterminated 12V wire from the 14-pin connector at the firewall to the area of the AFM.

You will love the harness! I ordered a standard harness and am determined not to cut into it for anything. If I go back to a MAF, I'll used either the unused cycling valve connector or the diagnostic port for 12 volts. I'll post details later, but have come up with non-invasive sources for most of the signals I might need.

[Latitude48]

Thanks for this thread, Tom. It's going to be very helpful as I just ordered one of these harnesses for our 951 since the exchange rate is currently pretty good. I added the MAF option, which includes a switched, unterminated 12V wire from the 14-pin connector at the firewall to the area of the AFM.

You will love the harness! I ordered a standard harness and am determined not to cut into it for anything. If I go back to a MAF, I'll used either the unused cycling valve connector or the diagnostic port for 12 volts. I'll post details later, but have come up with non-invasive sources for most of the signals I might need.

The MAF currently on our 951 gets power from the same pin in the 14-pin connector, but in a much less elegant way via a splice as I recall. Since I'm planning to install the F9T MAF when available I figured this would work out well. I know Joe currently sets up his NA MAF to get power from the coil, but I thought this would be a cleaner installation. Time will tell.

[Tom]

Thanks for this thread, Tom. It's going to be very helpful as I just ordered one of these harnesses for our 951 since the exchange rate is currently pretty good. I added the MAF option, which includes a switched, unterminated 12V wire from the 14-pin connector at the firewall to the area of the AFM.

You will love the harness! I ordered a standard harness and am determined not to cut into it for anything. If I go back to a MAF, I'll used either the unused cycling valve connector or the diagnostic port for 12 volts. I'll post details later, but have come up with non-invasive sources for most of the signals I might need.

The MAF currently on our 951 gets power from the same pin in the 14-pin connector, but in a much less elegant way via a splice as I recall. Since I'm planning to install the F9T MAF when available I figured this would work out well. I know Joe currently sets up his NA MAF to get power from the coil, but I thought this would be a cleaner installation. Time will tell.

I'm sure that will work great. I just confirmed that the diagnostic connector at the back of the glovebox (or on the corner of the DME bracket on later cars) has a 12v wire that runs directly to that same 12v pin in the 14-pin connector on the firewall. I plan to use that (and the ground wire also in that connector) for power in the cabin. It also has the knock signal from the KLR and an ignition pulse, so I plan to use it to make a tidy little connector that feeds my boost controller, knock counter, and wideband. I was temped to 3D print the connector, since I already did the other half for another project, but found them at Rose Passion and decided that was the path of least resistance. Those connectors are easy to hack since the wires just solder into the big pins, so if needed you can always solder an extra wire in without any hacky splices....

rose-kostal.jpg (71.31 KiB) Viewed 1501 times

[Tom]

One thing I'd suggest when installing this harness is to take very close note of how all the old wires are routed, where they are clipped and clamped, what goes over and under what, etc. Take tons of 'before' pictures! The new harness isn't baked into shape like the old one -- the snorkel points up straight and all the wires are super flexible and give no clue how they should be routed.

The new snorkel needs a clamp to hold it down. Since I didn't have the factory clamp, I opted to use a cheap stainless cushion clamp from Amazon at dr bob's suggestion. A 1-1/4" clamp is the best fit around the Kroon harness, but I opted to modify a 1-1/2" clamp to extend the tab 3 or 4mm to make for my steam vent fitting. I just pounded the bent end flat and re-bent it a little further away from the hole; then trimmed the rubber cushion part to fit, and had to drill the holes out to 8.5mm for the intake bolts.


Original on left; modified version on right.

kroon-modified-clamp.jpg (310.24 KiB) Viewed 1475 times

It worked!

kroon-clamp-installed.jpg (523.43 KiB) Viewed 1475 times

[Tom]

Yippee, got the car running this afternoon with actual electrons flowing through the Kroon harness. Started up on the first try! Connectors at the KLR and DME are super tight so had to get a bit creative there. Will share my solution and a few other thoughts in the next few days. I'll also go back and add an installation checklist in the first post. Next I need to work on the ancillary electronics (boost controller, zeitronix, and knock counter), and then finally will work on burning my own chip for this fairly unique set up (3 liter, big turbo, and mostly stock parts -- not unlike the factory 3 liter turbos really). Good day here at CP headquarters!

[ROB III]

Tom,
Are you still using a Profec B Boost controller? I still have a Profec B Spec II in the box which I bought 20 years ago, but I THINK the chip from the Vitesse Stage II set-up I bought (also 20 years ago) had a boost control function, but that is also still the box.

[Tom]

Tom,
Are you still using a Profec B Boost controller? I still have a Profec B Spec II in the box which I bought 20 years ago, but I THINK the chip from the Vitesse Stage II set-up I bought (also 20 years ago) had a boost control function, but that is also still the box.

Yes, I'm still using the original Profec B-spec with the big black solenoid box. I've tried others, but keep coming back to the simplicity of the Profec. I know VR offered a boost control function using his piggyback, but it relied on a MAC solenoid like all of the other EBCs I've tried. I was just never a fan (and/or never had the patience) to program in duty cycles for the MAC valves. I'm sure with a lot of trial and error, you could dial in the exact boost curve you want, but I like just having a knob I can turn up and down.

[ROB III]

but I like just having a knob I can turn up and down.
BINGO
Thank you

[Tom]

Still loving this harness and think it's probably the best money spent on my car in a long time!

That said, here's more on the connector issue I mentioned. The main 35-pin connector is supposed to hook in on one end and then clip into place with the shiny spring-metal latch on the other end. Same with the KLR. The problem is that I could not get the connector to latch no matter how hard I pushed, and without it latching, it kept springing up and unplugging itself.

The culprit appears to be the rubber weather strip seal inside the connector. The Kroon version is about 1.5mm thicker than the factory piece. I don't 'think' the factory rubber is just flattened out after being squished for 40 years, because it just don't look deformed in any way and is uniformly skinnier -- not just skinnier where the connector clamps down on it. The rubber is just sitting in its groove and can be picked out easily (no glue, etc.). So my solution was to just swap over the rubber pieces from my factory harness. You could also just remove the rubber altogether and probably never miss it.


Below: here's the latching mechanism holding a connector in place as designed.

kroon-latch-eampla.jpg (566.64 KiB) Viewed 1368 times

Below: Here is the factory rubber in the Kroon harness.

Kroon-connector-with-factory-WS.jpg (630.72 KiB) Viewed 1368 times

Below: And here is the rubber that comes in the Kroon harness -- notice how much higher it sits.

kroon-new-rubber.jpg (699.62 KiB) Viewed 1368 times

Below: here are a couple pictures showing the smaller factory piece compared to the Kroon piece. Given @Kroonwireharness's endless abilities to replicate rubber parts, I'm thinking they might want to create a thinner rubber gasket more akin to the one used by the factory.

kroon-rubber-cf.jpg (311.83 KiB) Viewed 1368 times

kroon-rubber-cf2.jpg (201.55 KiB) Viewed 1368 times

Below: if you don't have a skinny factory rubber piece available and don't want to go without the seal, another option that works is to put washers under the latching piece on the DME/KLR. Doing this raises the latch so that the connector doesn't need to be pushed down as far to latch.

kroon-fix1.jpg (469.69 KiB) Viewed 1368 times

kroon-fix2.jpg (517.64 KiB) Viewed 1368 times

[Latitude48]

My new Kroon harness for the 1989 951 arrived today. Guess I'll wait to open the box until Christmas It will be a while before I tackle the installation... I just decided to spring for it now while the exchange rate is favorable.

I was a bit surprised at the $105 UPS duty charge I prepaid as I only paid $45 total for nearly $3000 worth of Euro Golf R LED Matrix headlights shipped via FedEx from Latvia.