Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
MrPants's Avatar
 
Join Date: Mar 2003
Location: dfw, texas
Posts: 1,137
advice on making a volt gauge please

i suspect that my alternator is not charging the battery properly. i would like to be able to check it at any time (esspecially while driving).
i was thinking that i could run some alligator clip wires from the battery through the firewall into the cabin and then test it with my multi meter while in the car. that seems like a hassle.
so this is my question(s): is there any where at the fuse/relay board that would give me an accurate reading of the battery voltage? do any of the unused relay slots get full power from the battery? should the voltage at the battery with the car running vary at all or is it constant?
i am highly uneducated on all this electrical stuff so any advice would be greatly apprecited!
__________________
84 944 Non Alcoholic
Old 02-04-2004, 08:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
bearone2's Avatar
 
Join Date: Jun 2003
Location: Phoenix, AZ
Posts: 1,327
you need to take it from the battery. make some long cables, don't crimp them as you close the hood and connect to the digital/led volt meter. don't use a volt meter with a needle unless you have to.
__________________
87 951, K27/6, Almond Beige, 17" Turbotwist
87 944S, alpine white, 5sp died a violent death
84 944, silver/brown, auto, gone but not forgotten

"may the force be with you"
Old 02-04-2004, 09:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
One of the large red wires that connects to the positive terminal is the main buss feed to the fuse/relay panel.

If you clean the battery connections up including these wires you can use the 30 buss on the fuse block.

This way you only need to run a ground wire from the battery.

Then if you clean up the ground to the chassis from the battery you could connect the ground side of the volt meter to a grounding point under the dash.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 02-04-2004, 09:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
MrPants's Avatar
 
Join Date: Mar 2003
Location: dfw, texas
Posts: 1,137
Quote:
Originally posted by SoCal Driver
If you clean the battery connections up including these wires you can use the 30 buss on the fuse block.
i dont know the proper terminology. where is the "30 buss"?
im looking at this and it looks like that thinner red wire you mentioned goes to the DME relay (connection 2 on the "fuel pump relay" in the picture). am i reading that correctly?

will i get a proper voltage reading if i connect the negative lead from multi meter to the body or does it need a direct connection to the battery?
__________________
84 944 Non Alcoholic
Old 02-04-2004, 10:21 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Dec 2002
Location: Richmond, VA
Posts: 484
Remove the center console gage cluster and disconnect the clock. Make a splitter and run the extra leads up to the center speaker grill. Mount the voltmeter in the center speaker grill. Reconnect the clock and reinstall the center gage cluster.
__________________
Cliff Hipsher
'87 944 India Red
'86 951 Kalahari Metallic
Old 02-05-2004, 05:12 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Quote:
Originally posted by MrPants
i dont know the proper terminology. where is the "30 buss"?
im looking at this and it looks like that thinner red wire you mentioned goes to the DME relay (connection 2 on the "fuel pump relay" in the picture). am i reading that correctly?

will i get a proper voltage reading if i connect the negative lead from multi meter to the body or does it need a direct connection to the battery?
The "wire" I mention is the top one of the five horizontal "lines" on the schematic drawing. This is actually a thick copper stamping that is part of the fuse/relay block assembly. One of the heavy red wires from the positive battery terminal goes directly to this buss. It's hot all the time.

The #15 buss is from the ignition switch. It is only hot when the key is turned on.

You can use a 12 volt test light to "see" the 30 buss. Connect the test light lead to a ground point and use it's points on the fuses. There are several that are always hot. The cooling fans are one of these.

Even if you go directly to the battery to source a volt meter you still have to use the connection terminals on the battery. If these are not clean then you will not get a true reading.

Get a VDO volt gauge. There are ones that will match your existing gauges. I have one in a box some where that I will eventually install. Also an amp gauge. Though a digital display mounted in the center speaker grill showing this info is a better idea.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 02-05-2004, 07:22 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
I'm off the hook.....
 
Join Date: Oct 2001
Location: 22 miles south, then 11 miles west of LAS
Posts: 2,895
There are voltmeters that plug in to the cig lighter. Funky, but they work.
__________________
No, I don't sing. Based there for too long.
Old 02-05-2004, 07:52 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 01:16 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.