L

layfin

Active Member

• Jul 5, 2021

• #1

Hi all.

I have a 1984 109 FFR 24v. The Fuel and Temp guages are both faulty. I searched the Forums for this issue and it appears that the Voltage Stabeliser is faulty. The wiring diagrams show this, however I cannot find one on my dash as indicated. Is it located somewhere else or is there some other issue.

Regards.

Chris.

 

Blackburn

Well-Known Member

• Jul 5, 2021

• #2

I was under the impression Military vehicles had a different type of gauge and do not need voltage stabiliser.
Have you a wiring diagram for the FFR

 

L

layfin

Active Member

• Jul 5, 2021

• #3

Yes, I have the MoD Hand Book which includes the wiring diagram, however, I don't see the Stabeliser in it. I have doubled checked the wiring and tried a new sensor in the cylinder head.

 

C

Colthebrummie

Well-Known Member

• Jul 6, 2021

• #4

They are usually fixed to the bulkhead behind the instrument binnacle.

Col

 

Blackburn

Well-Known Member

• Jul 6, 2021

• #5

You will need a military parts book as well as sensor may be a different part to civvy version.
Blanchards list a different gauge for military
https://pablanchard.co.uk/Gauge-Oil-Temp-Eng-IIA-Military-500555.
Give Blanchards a call they may be able to advise.

 

ExMil109

Active Member

• Jul 6, 2021

• #6

Blackburn said:

I was under the impression Military vehicles had a different type of gauge and do not need voltage stabiliser.

Click to expand...

Yes, it's a different gauge and doesn't need the stabiliser. The usual problem with these gauges is that they corrode internally and read high/max as soon as you connect the sender, but the same problem is sometimes down to bad earth on the gauge cluster.
Are your gauges reading too high or too low?

 

L

layfin

Active Member

• Jul 6, 2021

• #7

Going straight to high.

 

ExMil109

Active Member

• Jul 6, 2021

• #8

First thing to check is that the back of the gauge cluster has a good earth connection.
If that checks out ok then it's likely the gauges themselves have failed, but also worth checking in case the sender wire has shorted to earth somewhere. If you disconect the wire at the sender and the gauge drops to zero then it's likely the gauge; if it stays at max then there's a short to earth in the wiring.
You can dismantle the gauge cluster to check if it has corroded internally - I have some pictures of the gauge internals that I'll upload when I find them...

 

L

layfin

Active Member

• Jul 6, 2021

• #9

Great, thanks.

 

ExMil109

Active Member

• Jul 6, 2021

• #10

Here are the pictures of the Smiths gauge cluster internals. Each gauge has an internal earth connection that can corrode, so worth checking that these are clean and tight.
If that doesn't fix the problem, it's likely the gauges have failed - these Smiths gauges are not as robust as the thermal Jaeger ones that the non-military Series have.

 

L

layfin

Active Member

• Jul 6, 2021

• #11

Really appreciated, I will check that whenever it stops raining over here.