S4/Sprint wiring

[slowsprinter]

elan_modified_wiring.pdf

Hi Guys

I am in the process of rewiring my project Sprint. I decided that I was going to carry out some sensible wiring upgrades like adding some extra fuses and adding hazard lights, electric fuel pump and electric headlight lifters.

I decided to use Peter Wrisley's diagram (pdf link above) as the basis for my wiring and I have bought PM looms which I intended to modify. I also wanted to use his idea of using relays to control the electric windows. So I enthusiastically started ripping my dash wiring apart, labelling it all up and starting to rebuild. I built a small relay board for the windows and intend to mount it on my radio fitted into the dash. In the process of wiring up these relays I have hit on a snag. Please would one of you electrical gurus take a look at Peters Dash Harness diagram and tell me if it is correct?

I expected the 2 relays for the left window to mirror the 2 for the right window. It does not appear to be the case. Tags 86,87A on the right relays are earth (Negative), and 87 are positive. On the left pair of relays, the right hand relay tag 86 has a feed from positive and negative!! Please tell me if I am being a numpty but shouldn't the two 86 be connected together to Earth? Conversely the two 87 connected to the positive feed from Fuse 5?

I would be grateful for advice before I potentially smoke my new wiring
Thank you
Ian

[slowsprinter]

https://lotuselan.net/w/images/4/4f/Ela ... wiring.pdf

Oops I realised the link to the diagram did not format across to my post.

[Craven]

Without sending too much time on it, you will have a dead short on the ‘ top drawing’ set of relays.

[slowsprinter]

Thanks for the reply @Craven, so you agree that the diagram is wrong? It's just that this pdf has been kicking about for ages on the Forum, so I assumed it was all correct. I will now watch out for other mistakes as I go through. I just needed confidence and confirmation from someone else that there is an error there.

So on the 'dash harness' diagram, the wiring appears correct for the right window motor where 12v is applied to the coil of the relay from the switch which closes the contacts and provides higher current from fuse 5 down higher gauge cable to the motor? And that the wiring for the left set of relays is wrong in the diagram?

Ian

[Craven]

On the top drawing of relays, S128 + feed is connected to pin 86. Dash switch feeds 12v to pin 85 so relay will have same potential on both 86 and 85 and will not work.
Also as drawn, S128 is directly connected via pin 86 to pin 87a which is connected to ground = dead short.
Bottom set of drawing relays look correctly wired.

[slowsprinter]

@Craven
Thank you very much! Agreed. I am not too confident in my electrical knowledge, I appreciate the confirmation and I can get on with it!

Ian

[geni]

great, would it be possible to rectify the diagram(s) to make correct copies
It will help a lot of us.

[slowsprinter]

Geni

I am very sure my IT skills are not up to that job, hopefully someone can. Now that there are mistakes on the drawing I will be giving it all more thought as I go through.

Ian

[elansprint71]

What goes around... some years ago I decided to rewire my Sprint and bought a three-piece loom from Matty. I laid it all out in my living room floor and marked up all the terminations in an attempt to avoid problems on installation. There were getting on for twenty "mistakes" so I took it back to Matty and spoke with their electrical "expert" he said, "oh, they are all like that" I Have to modify them... at which point Matty himself wandered through. I tackled him and he said some thing like "Ovvviously, all Elans are different so our loom is generic" (i.e.wrong) in his presence I asked his "expert" to plug together the three sections. The two of them had less idea than I did. Apologies to long-term forum members who might have read this story about 18 years ago.