Electrical gremlins, wiring diagrams needed?

[markw996]

Hi,

 

As some of you know I have just taken delivery of a 94 Esprit S4, unfortunately it has quite a few small faults that I want to fix asap. I'm pretty confident with car electrics but a diagram would be helpful.

 

Does anyone know where I can download an S4 wiring schematic / diagram from?

 

1) Fuel gauge pegs to full violantly (suspect sender or wiring)

2) Alarm doesn't seem to work at all (it has ultrasonics so I presume there is an alarm)

3) Electric mirrors only work in some directions (suspect switch but would like to prove before buying one)

 

Thanks,

Mark.

 

[philip600]

Hi Mark, if you join the forum as a full member you can download the full workshop & parts manual. Certainly worth the money.

Phil.

[Jamie Garroch]

I didn't know that Philip. Mark, before I discovered TLF, I bought a set of 'hefty' (great for weight lifting!) original Lotus manuals from SJ Sportscars back in 2010 as follows:

 

B082T0327J WORKSHOP MANUAL ESPRIT 1988 to 1992 £116.91

F082T0327J WORKSHOP MAUNAL, ELECTRICAL SECTIONS £57.88

 

Regarding the alarm, mine recently went kaput and after dismantling the dash (I renewed the entire interior), I discovered that the ultrasonics weren't even connected!  The alarm/immobiliser is a Toad after market one so all wires are unmarked and black and there is zero electrical documentation so I suspect if I call them that they will say it's cheaper to install a new one than try to debug the existing install.

Edited August 8, 2013 by JamieG

[markw996]

JamieG, I have a Toad Ai606 installed in my Porsche (I fitted it and worked out all the wiring so I could splice it all into the loom of the old Sigma alarm that went wrong). It's a very common alarm so if yours is the same and if it's any help, then drop me an email and I'll gladly help if I can.

[Jamie Garroch]

Hi Mark. Thanks for the offer. I think mine's an older version and just called Toad MP5.  It has the main alarm unit (with siren) mounted in the front compartment and an interconnected immobiliser black box 'mounted' (thrown) into the area behind the radio. The wiring for a professional install is shocking. Poorly soldered connections others without any insulation and instead of neatly tie wrapped supports, half the loom is wrapped around the bonnet release handle.  I've just dug out the paperwork to get the model number and found the install certificate that says "lifetime warranty" so I may give them a call first to see if that's what it actually says it is.  Assuming Toad continued with unmarked black wiring looms, how on earth did you figure it out?

[markw996]

It wasn't too difficult, I just eliminated the obvious wires first i.e. permanent live, ignition live, earth (of which there are usually at least 2), then found the two indicator wires by testing the remaining wires with a multimeter while arming and disarming the alarm. You will also usually have 4 wires for immobilising (2 for ignition, 2 for starter motor) which are easy to work out and they will go short circuit when alarm is disarmed enabling you to split them into pairs. You can then cut one pair and see if the starter will turn, that will tell you which is which. Any remaining wires will be for an LED and if fitted a boot release and / or electric windows etc. It really helps if you can find a wiring diagram for an alarm that is similar, then at least you know which wires you are looking to identify.

Edited August 8, 2013 by markw996

[Jamie Garroch]

I just got my car back after it's been away for a total engine rebuild sinceOctober 2013 and it won't start due to no earth on the coil. I initially thought it was the immobiliser but am not sure now since the MP5 unit still enables/disables the other expected sub systems. I'd love to get a system diagram for the MaxPower MP5 but also interested in anyone knowing what could possible interrupt the earth connection to the coil (there is 12V on the positive side but only when earthing anywhere but the -ve side of the coil!)