Thread: No start. Blowing Maxi Fuse 2

I've not heard of it before! I hope it's an easy fix!

If you get to Townsville and run into dramas, gimme a PM or call (040 87 84 37 5) and ill rip one of my compressors off the Rangie to see if that sorts your issue.

Cheers
Keithy

I have a spare compressor. I will check the measurements you ask for and post in the morning. I will let you know the startup current on the compressor.

It may be another component which is in parallel to the compressor which is drawing excess current in addition to the compressors normal startup current - the combined draw blowing the CB. Do you have the electrical manual fr the p38 and which month and year is it.

The car is a 95 model. According to the electrical troubleshooting manual I have on the laptop, the fuse only supplies the starter solenoid (via relay 16), the compressor and the diaphragm valve on the EAS block (both via relay 20).
I've pulled relay 20 and will do some driving today to prove it isn't the starter motor (which is only 4 years old). The compressor has been pumping slowly, so could have suffered a mental breakdown.







Keithy, thanks for the offer. Hopefully I'll be right to limp home after xmas.

The compressor draws 11 amps under load and the impedance is0.4ohm.

You must have a wire with insulation worn through somewhere between maxi fuse 2 and the standard fuses that drive parallel circuits from the maxifuse feed.
Do a thorough inspection looking for worn looms first - you may quickly find the bad wire.


Failing that, You need a to insert a resetable circuit breaker into the maxi fuse position and remove connectors sequentially on each line until you find the short to earth.

If you dont have one then there should still be the odd autoelectrician still open.

Good luck and make sure you report back if you solve this issue.

I forgot to say that a very common source of short to earth in the air suspension circuit is in the wiring that leads down between the metal valve block and the air compressor box . However that should only lead to an intermediate fuse issue and probably not the main maxi fuse. Either way you will probably find chaffed wires there - I did when I overhauled the valve block..

Peter, Thanks for that. I'll do further tracing.


The car is starting fine with relay 20 out and with a bit of manual tweaking of airbag heights is going OK, so holidays services will continue as planned. I'll check for 0.4 Ohm measured at the compressor terminals in the meantime.


My wiring schematic shows no sign of any smaller fuses downstream on the main power wires, so my plan is to check Ohms from relay 20 to the compressor connector, plus the connector to earth. Hopefully will narrow down the problem area.


No chafed wires in the EAS box, I've only replaced the valve block a year ago. Put a new seal in the compressor then, but it still wasn't pumping up very fast. The compressor has oozed a bit of oily burnt smelling goo between the motor and pump head.
I've looked at the Island 4x4 site, and there is a Dunlop compressor for 150 quid or an OEM compressor for 200. Any experiences with the Dunlop one?
Thanks.... Troy

I have a Dunlop one as my second, no dramas from me after 2yrs of use.

Well, the story comes to an happy ending. Got the beast home again with a top up to the airbags required once only, even on 10 year old airbags. The air tank pressure has stayed at 100psi for 2 weeks, new Dunlop compressor from island 4x4 delivered in 7 days. Fitted in half an hour, replaced EAS relay and up she rises!


Much faster pump up than before so the old compressor must have been very tired.


My recommendation... keep a 30A maxifuse in your spares kit.


Troy N