I never liked the wimpy Euro-sound of the 512TR horns, so it seemed an opportune time to replace them while the steering rack was out. I got these Hella horns, a definite upgrade: Image Unavailable, Please Login Image Unavailable, Please Login First, make sure the battery power is disconnected at the cut-off switch in the front boot. Then remove the access panel in front of the driver's side wheel well (7 bolts and washers, 10 mm wrench. You should see something like the next photo. Then remove the two locknuts and washers that hold the horn compressor to the frame bracket (10 mm), disconnect the electrical harness, unplug the plastic air hose that goes to the horns and remove compressor.
The horns themselves are each held in place with 10 mm bolts and lock nuts. Just loosen and they slide rearward. Image Unavailable, Please Login Image Unavailable, Please Login
One Hella horn will bolt to the horn bracket and the other will bolt to the compressor bracket. Re-use the 10 mm bolts and the washers/locknuts. Image Unavailable, Please Login Image Unavailable, Please Login
The only slightly tricky part is fabricating a wiring harness that connects the existing electrical pos/neg wires to BOTH horns. 12 g wire, heat shrink crimp connectors and a heat gun do a professional job. The Hella horns come with a relay, but the 512TR already has a horn relay and fuse in place. On the Hella horns, the #87 marked terminal is positive. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Now just connect your fabricated wiring harness to the existing horn wires (black is negative), turn on the battery power and give the new horns a blast. The Hellas have a great sound. You will be pleased. Then just re-attach the access cover and we are done. This was hands down the easiest modification I have ever made on this car, and, best of all, no brackets were harmed during the process. Save the horns in case the next owner is an "original or die" guy (or sell them on EBay).
Thanks for the write up .. it is always nice to see how to get to certain components Sent from my moto g power using Tapatalk
Nice write up and quality work but not for purists. There must be something wrong with the original compressor (Maybe dried out?). Not much can compete with the sound of the original horn if it's in good working condition. Do yourself the favor and save the old horn. Some buyer in the future will appreciate to have the legendary Fiamm horn included in the deal. Best, Peter
Thanks for the advice, Peter. The horn works perfectly and sounds like every other 512TR horn I've ever heard. Just not my cup of tea is all.
