Miss firing 380 SL

Myros

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Malcolm

I'm old enough to remember having to do it, as well as being shown how to by my Dad. Limited funds as a spotty youth and a VW beetle that needed something doing every 3,000 miles gets you into good habits, oil and plugs-wise.
I think it's one of the things I like best about the SL, even though it's hideously more complex than a VW, you can still do stuff to it, and reap the rewards.
 
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Isdyldan

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It's definitely as lose connection somewhere connecting to the pod. There is a large round connector (about 14 pin I think) - does anyone know which colour wire does what please? I can't understand the diagram in the Haynes manual.
Thanks again!
 
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Isdyldan

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I am now really confused - I dismantled the instrument pod and checked the pcb for loose connections but all seemed ok. I discovered that pins 8 & 9 from the round bakerlite connector fed the battery light, so checked that there was 12 volts across 8 & 9 with the ignition on, and there was. I used a spare 12v battery and some wires and put to pins 8 & 9 on the pod and the battery light lit up. With the connector back in place and ignition on the lamp still will not come on! I am fairly sure it is not a bad connection, so somehow having the whole connector in place is somehow telling the lamp not to come on. Any ideas please??
By the way, if ever you have to open the bakerlite round 14 pin connector, be careful to note the order - I almost had a disaster!
 
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Isdyldan

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Right, it's a combination of poor connections and the round 15 pin connector having been messed about with in the past. Could anyone help please by letting me know the pin-out details for this connector for a 1981 380SL ? My Haynes book only covers 350 and 450SL's unfortunately and I've been unable to find the correct manual. The pin-out details seem to change year by year for some reason too!
Many thanks - it's beginning to drive me mad!
 

Myros

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dan I sent you an e-mail

with some wiring diagrams I found. I don't know how good they are, but check your in box.
 
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Isdyldan

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That's brilliant thanks! I now just need to work through what I have where!

Regards, Dylan
 
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Isdyldan

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Many thanks for your help to date Myros. Unfortunately the wiring on those diagrams differ to the wires I have. I thought I had it sorted using the diagram from the Haynes book I have (covering 350SL & 450SL), but when I went to indicate the fuel and oil pressure gauges flicked up & down violently!
I think I will have to search the forums again and possibly start a new thread as this issue doesn't really match the title any more.
Thanks again, Dylan.
 

Myros

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dylan, sorry about the diagrams

I had the same thing happen to me with my 124 when the multi-pin connector came apart in my hands. Even using the wiring from the haynes, it was all wrong, and I had the oil level warning flashing with one indicator.
The 107 isn't as easy to work on, as I could just test connections with the cluster resting between the wheel and dash on the 124.
It really will be one for your test lamp and the help of a mate. Use a digital camera or make sketches and notes of what you do. You may need it.
Re your problem, you've obviously got the feeds from the indicators going to the gauges. Set the indicators going in turn and check the feeds and you'll soon find which they are. You'll need to fire up the engine to get the feed for oil pressure, but the tank feed will come live with the ignition, so again, you should find them ok. Don't switch anything about until you think you've traced the four feeds in question, then do them one at a time.
Sorry if that sounds like egg-sucking.
In the meantime I'll try and find some more diagrams, but given my lack of aptitude with computers, that could take me a while.
 
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Isdyldan

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Hi - well I think I have had a major break-through. Most gauges and lights work now (although I haven't started the engine yet so not sure about oil pressure). The battery light still isn't lighting but there is 12V at the pins which run to it. The circuit on the pcb runs from the +ve through a resistor, a diode, the lamp, & then back to the other pin. The resistor seems to have gone open circuit. I'm not sure how to test the diode, but the burnt out resistor seems to be a probable cause of my problem, unless of course it had burnt out due to another fault! I'll remove it from the pcb & see if I can still see what value it should be - most of the paint has flaked off it. Does anyone know what it should be please?
 

television

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The diode will be a standard silicon, and will measure around 2k to 5k in one direction and open circuit infinity in then other

Re the resistor, there no circuit diagram on these things.

It is possible to work some resistors out from the burnt one.

This depends on the construction, carbon,metal film,ww etc.

If you get stuck you can post it to me, and I can try and work it out for you
 

Myros

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Keep up the good work malcolm

Dylan, I've sent you some scanned diagrams from a 380 this time. check your inbox.
 
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Isdyldan

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All working fine now - thanks to everyone. Had a great weekend cruising around with the 8V burbling away! The only issue is that my wife has to go in the back as our 2 year olds seat will only fit in the front seat - will research that problem next!
Thanks again.
 

Alex M Grieve

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All working fine now - thanks to everyone. Had a great weekend cruising around with the 8V burbling away! The only issue is that my wife has to go in the back as our 2 year olds seat will only fit in the front seat - will research that problem next!
Thanks again.

A test of who is the most loyal member of the family is to put your wife and your dog in the boot and drive around for a while. Then stop and open the boot and see who gives you the better welcome!

Based on that, if anyone goe in the boot, it should be the 2 year old!! :rolleyes:
 

Myros

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got the munchkin taped as well

you need a Britax Vario-ronny. It's like a table they sit under, with a slot in it that the lap belt ( or a 3 pointer) They hold them up quite well, come up to their chests and stop them lolloping around in the back. Not common here, I got ours mail order from a chap in Germany. LMk if you need more details.
 

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