voltage spikes

Lance · Post by **Lance** » Fri Aug 14, 15 10:17 pm

Hi, any advice would be helpful please.
did some rewiring on my dart this week eliminating the duff ammeter and installing a new volt meter, when I started the car the volt meter was reading 12v, as the revs increased so did the voltage reading up to 16v !! the reading was the same at the battery terminal's, I assume the voltage regulator is up the creek ?? if this is the case where's the best place to get a replacement.

Pete · Post by **Pete** » Fri Aug 14, 15 10:28 pm

Yep, sounds like the Voltage regulator is toast - should be about 14.7 Volts...

Lots of suppliers - USAutomotive, WASP, John Wolf Racing, eBay...not heavy money.........

Lance · Post by **Lance** » Sat Aug 15, 15 8:32 am

Thanks very much Pete.

Dave81 · Post by **Dave81** » Sun Aug 16, 15 9:31 am

Lance wrote:Hi, any advice would be helpful please.
did some rewiring on my dart this week eliminating the duff ammeter and installing a new volt meter, when I started the car the volt meter was reading 12v, as the revs increased so did the voltage reading up to 16v !! the reading was the same at the battery terminal's, I assume the voltage regulator is up the creek ?? if this is the case where's the best place to get a replacement.

This sounds familiar........

I had the very same issue but topping out at 17v.

Check that the VR and electro ignition is earthed properly first.
I then changed the VR, EI and the alternator.....was still the same even after doing the ammeter bypass. So could only be the wiring. But I ran a new wire.........yes, but what I didn't expect was that the two wires that run from alt through to ballast and coil were fubard. Within the first few inches of wire I found a few dodgy wiring connectors that had incinerated the sheath and basically all he wires were shorting. Luckily no fire, but it was fooling the VR into under reading and allowing it to overcharge. It cooked the gellpack on the EI nicely.

So check here first....

Dave81 · Post by **Dave81** » Sun Aug 16, 15 9:35 am

Page 4 of my workshop thread;

http://www.moparuk.com/forums/viewtopic ... c&start=60

My tech Q at the time:
http://www.moparuk.com/forums/viewtopic.php?t=47189

Hope you find the issue Lance!

Lance · Post by **Lance** » Mon Aug 17, 15 11:13 am

Thanks Dave, no electronic ignition at the moment and as far as I can tell, the wiring looks unmolested, so like you I've gone ahead and ordered a new VR but I will take your advice and go back through the loom and also recheck the earthing.
When I checked the voltage the gauge tops at 16v and that was pucker point for me so may well go higher!!
Anyway, if you're interested, I'll let you know the results.

Lance · Post by **Lance** » Mon Aug 17, 15 11:16 am

Dave, forgot to ask, when you did the MAD electrical ammeter bypass did you fuse the alternator feed to the starter relay ?

Dave81 · Post by **Dave81** » Mon Aug 17, 15 1:55 pm

Lance wrote:Dave, forgot to ask, when you did the MAD electrical ammeter bypass did you fuse the alternator feed to the starter relay ?

Yes mate.

From memory (I can check tonight).

Due to the fact I couldn't find comparative fusible links here in the UK, I put a 25amp inline fuse where it states a 16 gauge wire (in car electro systems).
And put a 50amp block fuse where it asks for a 14 between alt and starter solenoid.

I'm running a 65 Amp Alt and according to my research they should never exceed 75% of their rating in normal use, so this was also used as a safety device. I have spares in the car just in case, as when the 25amp fuse blows it kills the car!

I've run the car many times and not had an issue. Ive never had a radio and I deleted the heater due to it not working, so gauges and lights are the only daily load.

I've also tried wipers on speed three and main beam.......just keeps on working!

Dave999 · Post by **Dave999** » Mon Aug 17, 15 2:12 pm

sounds like your regulator isn't earthed properly

it measures voltage from battery above 0 volts **

if its earth is above 0 volts it sees battery voltage minus what its earth is
and pumps too much into the alternator to make up for what it thinks is a loss

run a wire from the bolt that holds the regulator down direct to the battery - and see if things improve

** if it thinks its casing is at 0 volts and its actually at 2 volts, when it tries to see 14.7 at the battery its only sees 12.7volts

therefore its stuffs more current into the alternator windings until it see's what it thinks is 14.7 which is now 16.7 when you measure at the battery

stick volt meter to battery + and battery - with car running

then stick volt meter to battery + and the case or mounting screw of the regulator

if you see a smaller voltage its an earthing issue with your regulator if you see the same voltage the regulator is stuffed

Or if its mechanical it needs adjustment, its been set up for Minnesota/Canada/arctic ambient temperatures .

Dave

Lance · Post by **Lance** » Mon Aug 17, 15 9:29 pm

Thanks Mr T and Mr G,
Ok, followed your instructions Dave and both voltage readings are the same so next step is the new VR, see what the score is then !
thanks again for the advice fellas.

Dave81 · Post by **Dave81** » Mon Aug 17, 15 9:52 pm

Just to top it off make sure the battery negative to ground and engine block to ground connections are in good condition. All that, plus the new VR should hopefully sort the issue!

Mopar Muscle Association UK

voltage spikes

voltage spikes

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voltage spikes