The Service Manual pages MN-20 and MN-25 show an ECU grounding post in the ELISE back when the ECU was mounted in the engine compartment.
I don’t see a ground post in around the rear bulkhead in the Exige - so is there one or not?
Bonus Question - anyone here an expert with the wiring in A/C cars? Between the poor diagram in the Service Parts Manual and Mr. Massey’s retirement, I need help in deciphering what’s what.
You need Andy ‘Haynes Manual’ Dovey for this…he’ll be along in a minute as he’s actually in the country somwhere…
I am pretty sure the ECU earth is on the rocker cover in the engine bay, but as Benja has said, Andy D is your man.
There is no earth post for the standard K series ECU - all the earths go through the bulkhead 48 pin plug to the ground on the chassis - there are two signal earths pins 17 and 10 and 2 power earths pins 38 and 31.
You can check that out on page 30 of the service manual.
With the Honda ECU the earth is on the rocker cover …
Whats your problem with the AC wiring ?
AndyD - thanks for confirming the ECU earths confusion.
A/C: The problem is the recirc pump doesn’t work anymore. My A/C was removed at the factory, but the recirc pump was kept in place b/c preventing heat soak was perceived as a feature worth keeping on a track-only USA car. It has operated fine over the past 8 years.
I hooked up a small 12 volt battery to the recirc pump’s leads and it burbled away just fine. Next I’d like to test the control circuit to see if the relay works and the wires from the relay to the pump are alright.
However, I recently examined the A/C relay box (aka Fan control module). Not all the colors on my wires match the diagram on page PH-24. Exasperating. While the heat soak relay is separate from this module, given the discrepancies I’ve had with PH-24, is the heak soak portion of the diagram correct, or am I flying semi-blind?
Here’s a humorous example I did solve - My Cooling Fan #1 has a blue ground wire that according to PH-24 is supposed to be blue with a slate stripe. Then I noticed a slate colored piece of TAPE wrapped around each end of the wire! I guess the diagram is in fact correct, eh?
Bob